These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Influence of different maceration time and temperatures on total phenols, colour and sensory properties of Cabernet Sauvignon wines.  

PubMed

Maceration and fermentation time and temperatures are important factors affecting wine quality. In this study different maceration times (3 and 6 days) and temperatures (15? and 25?) during production of red wine (Vitis vinifera L. Cabernet Sauvignon) were investigated. In all wines standard wine chemical parameters and some specific parameters as total phenols, tartaric esters, total flavonols and colour parameters (CD, CI, T, dA%, %Y, %R, %B, CIELAB values) were determined. Sensory evaluation was performed by descriptive sensory analysis. The results demonstrated not only the importance of skin contact time and temperature during maceration but also the effects of transition temperatures (different maceration and fermentation temperatures) on wine quality as a whole. The results of sensory descriptive analyses revealed that the temperature significantly affected the aroma and flavour attributes of wines. The highest scores for 'cassis', 'clove', 'fresh fruity' and 'rose' characters were obtained in wines produced at low temperature (15?) of maceration (6 days) and fermentation. PMID:23703104

?ener, Hasan; Yildirim, Hatice Kalkan

2013-12-01

2

Total-colouring of plane graphs with maximum degree nine  

Microsoft Academic Search

The central problem of the total-colourings is the Total-Colouring Conjecture, which asserts that every graph of maximum degree admits a ( + 2)-total-colouring. Similarly to edge-colourings—with Vizing's edge-colouring conjecture—this bound can be decreased by one for plane graphs of higher maximum degree. More precisely, it is known that if 10 then every plane graph of maximum degree is (

Lukasz Kowalik; Jean-Sebastien Sereni

3

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)

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.

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

2008-12-01

4

Colloidal approach to prepare colour blends from colourants with different solubility profiles.  

PubMed

Food colouring plays a vital and a determining role in the processing and the manufacturing of food products because the appearance of products is critical for attracting consumers and influencing their food choices. However, factors such as legislative restrictions, limited number of approved colourants and the processing, formulation and stability issues of the natural colourants severely limits the application of food colouring in actual product formats. Hence, finding alternatives to the currently utilised formulation practises, represents an important area of research. Here, we report a simple colloidal approach to prepare colour blends by co-incorporating colourants with contrasting aqueous solubility profiles in composite colloidal particles. Curcumin and indigocarmine were selected as water insoluble and water soluble food-grade colourants respectively and incorporated in the colloidal particles prepared from food protein-zein. Composite particles obtained by loading of curcumin and indigocarmine (at different ratios) had mean particle size ranging from 76 to 300nm. The spherical shape of the colloidal particles was confirmed using transmission electron microscopy and the colloidal dispersions were further characterised using UV-Vis and fluorescence spectroscopy. The incorporation of colourants in colloidal particles led to the generation of different shade of colour in yellow-green-blue range. The encapsulation also led to the stabilization of individual pigments against photodegradation. Such composite colloidal particles could potentially serve as an approach for developing tuneable colouring system for food and nutraceutical applications. PMID:23790940

Patel, A R; Heussen, P C M; Dorst, E; Hazekamp, J; Velikov, K P

2013-11-15

5

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

6

Total light flux and colour of solar corona  

NASA Astrophysics Data System (ADS)

Measurements were made of the light flux and color of the corona in 1.03-6.0 solar radii with a multiple-band electrophotometer. The effective wavelengths of the instrument are 450, 555, 650 and 940. In one of them, the 555 band, the spectral rresponse defines a system that is in close agreement with the spectral response of the human eye. The results of the measurements are as follows: (1) the total light flux of the corona Lc is equal to 1.23 times 10 to the minus 7th power L(Solar); (2) in 555, 650 and 940 bands, there is no color difference between the corona and the photosphere.

Hao, Y.

7

Quantitative analysis of six lignans in fruits with different colours of Schisandra chinensis by HPLC.  

PubMed

A simple and rapid high-performance liquid chromatography method was utilised for the simultaneous determination of six major lignans in Schisandra chinensis with different colours continuously for the next 2 years. Six lignans were successfully separated on a C18 column at 254 nm using a gradient of acetonitrile and water. The assay was applied for analysing six lignans in the different colours of fruits of S. chinensis such as red, pink or white, and the component stability for the next 2 years was also detected. The result indicated that the total content of lignans in fruits with different colours varied remarkably, which was relatively high in red fruits, followed by white fruits and the lowest in pink fruits. Moreover, the contents of lignans in the samples of S. chinensis examined for the next 2 years changed irregularly and marginally. PMID:24650174

Sun, Dan; Li, Qian; Li, Hongbo; Li, Yanhui; Piao, Zhongyun

2014-01-01

8

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

PubMed

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. PMID:23194541

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

2013-02-15

9

Colour-specific differences in attentional deployment for equiluminant pop-out colours: evidence from lateralised potentials.  

PubMed

We investigated how target colour affected behavioural and electrophysiological results in a visual search task. Perceptual and attentional mechanisms were tracked using the N2pc component of the event-related potential and other lateralised components. Four colours (red, green, blue, or yellow) were calibrated for each participant for luminance through heterochromatic flicker photometry and equated to the luminance of grey distracters. Each visual display contained 10 circles, 1 colored and 9 grey, each of which contained an oriented line segment. The task required deploying attention to the colored circle, which was either in the left or right visual hemifield. Three lateralised ERP components relative to the side of the lateral coloured circle were examined: a posterior contralateral positivity (Ppc) prior to N2pc, the N2pc, reflecting the deployment of visual spatial attention, and a temporal and contralateral positivity (Ptc) following N2pc. Red or blue stimuli, as compared to green or yellow, had an earlier N2pc. Both the Ppc and Ptc had higher amplitudes to red stimuli, suggesting particular selectivity for red. The results suggest that attention may be deployed to red and blue more quickly than to other colours and suggests special caution when designing ERP experiments involving stimuli in different colours, even when all colours are equiluminant. PMID:24188915

Pomerleau, Vincent Jetté; Fortier-Gauthier, Ulysse; Corriveau, Isabelle; Dell'Acqua, Roberto; Jolicœur, Pierre

2014-03-01

10

Methodology for constructing a colour-difference acceptability scale.  

PubMed

Observers were invited to report their degree of satisfaction on a 6-point semantic scale with respect to the conformity of a test colour with a white reference colour, simultaneously presented on a PDP display. Eight test patches were chosen along each of the +a*, -a*, +b*, -b* axes of the CIELAB chromaticity plane, at Y = 80 ± 2 cd.m(-2) . Experimental conditions reliably represented the automotive environment (patch size, angular distance between patches) and observers could move their head and eyes freely. We have compared several methods of category scaling, the Torgerson-DMT method (Torgerson, W. S. (1958). Theory and methods of scaling. Wiley, New York, USA); two versions of the regression method i.e. Bonnet's (Bonnet, C. (1986). Manuel pratique de psychophysique. Armand Colin, Paris, France) and logistic regression; and the medians method. We describe in detail a case where all methods yield substantial but slightly different results. The solution proposed by the regression method which works with incomplete matrices and yields results directly on a colorimetric scale is probably the most useful in this industrial context. Finally we summarize the implementation of the logistic regression method over four hues and for one experimental condition. PMID:20883341

Laborie, Baptiste; Viénot, Françoise; Langlois, Sabine

2010-09-01

11

Cyclic Colour Change in the Bearded Dragon Pogona vitticeps under Different Photoperiods  

PubMed Central

The ability to change colour rapidly is widespread among ectotherms and has various functions including camouflage, communication and thermoregulation. The process of colour change can occur as an aperiodic event or be rhythmic, induced by cyclic environmental factors or regulated by internal oscillators. Despite the importance of colour change in reptile ecology, few studies have investigated the occurrence of a circadian rhythm in lizard pigmentation. Additionally, although colour change also entails changes in near-infrared reflectance, which may affect thermoregulation, little research has examined this part of the spectrum. We tested whether the bearded dragon lizard, Pogona vitticeps, displays an endogenous circadian rhythm in pigmentation changes that could be entrained by light/dark (LD) cycles and how light affected the relative change in reflectance in both ultraviolet-visible and near-infrared spectra. We subjected 11 lizards to four photoperiodic regimens: LD 12?12; LD 6?18; LD 18?6 and DD; and measured their dorsal skin reflectance at 3-hour intervals for 72 hours after a habituation period. A proportion of lizards displayed a significant rhythm under constant darkness, with maximum reflectance occurring in the subjective night. This endogenous rhythm synchronised to the different artificial LD cycles, with maximum reflectance occurring during dark phases, but did not vary in amplitude. In addition, the total ultraviolet-visible reflectance in relation to the total near-infrared reflectance was significantly higher during dark phases than during light phases. We conclude that P. vitticeps exhibits a circadian pigmentation rhythm of constant amplitude, regulated by internal oscillators and that can be entrained by light/dark cycles. PMID:25354192

Fan, Marie; Stuart-Fox, Devi; Cadena, Viviana

2014-01-01

12

Changes in colour and texture and their relationship with eating quality during storage of two different dessert bananas  

Microsoft Academic Search

The behaviour during storage at 20°C without any controlled atmosphere of two different varieties of dessert bananas from the Musa cavendish AAA group and the Musa paradisiaca L. AAB group was studied. Changes in instrumental colour and texture, and in a number of a sensory attributes (“green colour”, “yellow colour”, “colour uniformity” and “quantity of dark spots” of banana peel

A. Salvador; T. Sanz; S. M. Fiszman

2007-01-01

13

Observations with a different approach to morphological colour variation in an isopod population (Crustacea: Isopoda)  

Microsoft Academic Search

Morphological colour variation in Idotea baltica basteri Audouin, 1827 (Isopoda: Crustacea) is reported for the first time on populations from a brackish water lake (Kucukcekmece\\u000a Lagoon) in Turkey. According to pigmentation characteristics, the isopods were described and sorted to ten different colour\\u000a morphs which are named as maculata, maculata-lineata, uniformis, uniformis-lineata, immaculatum, immaculatum-lineata, nigrum, nigrum-lineata, albafusca,\\u000a and albafusca-fasciatum. The similarity

Belgin Camur-Elipek

2009-01-01

14

Gender differences in colour naming performance for gender specific body shape images.  

PubMed

Males are increasingly subjected to pressures to conform to aesthetic body stereotypes. There is, however, comparatively little published research on the aetiology of male body shape concerns. Two experiments are presented, which investigate the relationship between gender specific body shape concerns and colour-naming performance. Each study comprised a between subject design, in which each subject was tested on a single occasion. A pictorial version of a modified Stroop task was used in both studies. Subjects colour-named gender specific obese and thin body shape images and semantically homogeneous neutral images (birds) presented in a blocked format. The first experiment investigated female subjects (N = 68) and the second investigated males (N = 56). Subjects also completed a self-report measure of eating behaviour. Currently dieting female subjects exhibited significant colour-naming differences between obese and neutral images. A similar pattern of colour-naming performance was found to be related to external eating in the male subjects. PMID:11234250

Elliman, N A; Green, M W; Wan, W K

1998-03-01

15

Condition-dependent expression of red colour differs between stickleback species.  

PubMed

Sexual isolation may arise when male mating traits and female preferences differ between species. Such divergence in mating traits is likely to occur when the strength or targets of sexual selection differ. Therefore, by comparing the traits under sexual selection in closely related species and the nature of preference for those traits, we can gain insight into when sexual selection contributes to sexual isolation and how it does so. Collecting these data is no easy undertaking. To simplify this comparison, I use the presence and extent of condition dependence in traits to determine whether directional sexual selection is acting on them. Condition dependence thus serves as a signature of sexual selection. I investigate differences in sexual selection on red nuptial colour in limnetic-benthic species pairs of three-spined sticklebacks. I evaluate condition dependence by comparing the strength of the relationship between colour and condition, and the magnitude of variance in red nuptial colour to other colour traits and to nonsexual traits. I find that limnetic males have strong condition-dependent expression of red nuptial colour whereas benthic males have at most weak condition-dependent expression. Ancestral anadromous males show no condition dependence. This suggests that colour is under strong directional sexual selection only in limnetics and that this is the derived state. Moreover, I find that the strength of female preference for red is related to the extent of condition dependence. The extent of condition dependence is also associated with the importance of colour differences to mate recognition. These results show that differences between these species in the action of sexual selection underlie their sexual isolation. PMID:17584250

Boughman, J W

2007-07-01

16

Highly sensitive colour change system within slight differences in metal ion concentrations based on homo–binuclear complex formation equilibrium for visual threshold detection of trace metal ions  

Microsoft Academic Search

A new technique of expressing slight differences in metal ion concentrations by clear difference in colour was established for visual threshold detection of trace metal ions. The proposed method is based on rapid change of the mole fraction of the homo–binuclear complex (M2L) about a ligand in a narrow range of the total metal ion concentration (MT) in a small

Hitoshi Mizuguchi; Hiroshi Atsumi; Keigo Hashimoto; Yasuhiro Shimada; Yuki Kudo; Masatoshi Endo; Fumihiko Yokota; Junichi Shida; Takao Yotsuyanagi

2004-01-01

17

Usage pattern and exposure assessment of food colours in different age groups of consumers in the State of Uttar Pradesh, India.  

PubMed

The present study aims to investigate the nature and levels of colours in food items and to undertake risk assessment vis-a-vis intake among different age groups of consumers in the State of Uttar Pradesh, India. A total of 478 edible foodstuffs were analysed, and of six permitted colours, Sunset Yellow FCF (SSYFCF) and Tartrazine were most popular, and two non-permitted colours, namely Metanil Yellow and Rhodamine B, were encountered. The study showed a marked improvement in the trend of use of non-permitted colours over previous surveys, with 90% foods now resorting to approved food colours. However, 59% of foods employing permitted colours exceeded the maximum allowable limit, with average quantities crossing the threshold of 100 mg kg(-1) in most food commodities. The intake of SSYFCF exceeded the acceptable daily intake (ADI) for children and adolescents by 88% and 39%, respectively, and was statistically significant when analysed by error bars and distribution curves. In adults, SSYFCF saturated 59% of the ADI. For Carmoisine, Tartrazine and Ponceau 4R, saturation of ADI ranged from 27.4% to 90.3% in children and adolescents and from 10.8% to 47.6% in adult subjects. These results indicate that children and adolescents are more vulnerable to higher intakes of food colours compared with the adult population. Allowing a uniform level of all colours in foods under Indian rules, notwithstanding wide variations of 250-fold in their allocated ADIs, could be one reason for the higher intake and hence only technological need-based levels of individual colours are desired to be prescribed. PMID:19890754

Dixit, S; Purshottam, S K; Gupta, S K; Khanna, S K; Das, M

2010-02-01

18

Evolution of sex differences in microhabitat choice and colour polymorphism in Idotea baltica  

PubMed

We studied microhabitat choice of colour morphs, causes of sex differences in microhabitat use and colour polymorphism in Idotea balticaa marine isopod living mainly on the brown alga Fucus vesiculosusThe colour morphs differ in frequencies between the sexes and appear to be cryptic on the visually heterogeneous FucusIn this study, no colour-morph-dependent preference for visually matching microhabitats was found. However, in all three experiments conducted, females were found more often on the lower parts of the Fucus than males. The microhabitat choice of the sexes was directed by some character of Fucus itself, not by preferred height within the plant. However, the sexes did not choose differently between upper and lower parts of Fucus as food. The food choice and substrate choice correlated in males but not in females, implying that microhabitat and feeding preferences are more tightly associated in males. We propose that the stronger preference for the less exposed lower parts of Fucus as microhabitat and the lack of correlation between microhabitat and substrate choice in females can be explained in terms of a greater investment in anti-predator protection in females than in males. Thus, the sexual difference in microhabitat choice would ultimately result from different strategies maximizing reproductive success in males and females. We suggest that the sexual differences in coloration and colour morph frequency in I. baltica are explained as an adaptation to sex differences in patterns of habitat use.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour PMID:9344431

Merilaita; Jormalainen

1997-10-01

19

Effects of aposematic coloration on predation risk in bumblebees? A comparison between differently coloured  

E-print Network

Effects of aposematic coloration on predation risk in bumblebees? A comparison between differently.1111/j.1469-7998.2010.00709.x Abstract It has been proposed that sympatric bumblebee species form mimicry the predation rates of local bumblebees with those of imported non- native bumblebees, whose coat colour

Chittka, Lars

20

Assessment of different colour parameters for discriminating potential suspended sediment sources and provenance: A multi-scale study in Luxembourg  

NASA Astrophysics Data System (ADS)

Sediment colour has recently been used successfully to estimate suspended sediment sources in small catchments using the fingerprinting approach. The methodology offers opportunity for further research since it provides a rapid and cheap means for investigating sediment sources. However, the colour-based fingerprinting approach has not yet been tested in medium and large catchments. This paper aims to test whether colour parameters are capable of discriminating sediment sources in a nested system of seven sub-catchments ranging from 0.7 to 247 km 2 of the Attert River catchment, NW Luxembourg. Time-integrated suspended sediment samples and samples of potential sediment sources (land-use types and channel banks) were collected in all catchments. Sediment colour was then computed from diffuse reflectance spectrometry measurements (ASD FieldSpec-II spectrometer, 0.4-2.5 µm) taken over the visible wavelength range. Twenty-four colour parameters were derived from several colour space models (CIE xyY, CIE XYZ, RGB, Munsell HVC, Helmholtz chromaticity, CIELUV and CIELAB) and their ability to discriminate potential suspended sediment sources and provenance was evaluated and compared. Results demonstrated that time-integrated suspended sediment samples collected in the study catchments had statistically different colour values. Moreover, these values always represented a mixture of the colour values measured on potential suspended sediment sources in the catchment. Inter-source colour contrasts (land-use types and channel banks) were observed in all catchments (Kruskal-Wallis H-test). However, although colour is able to distinguish potential sediment sources in small catchments, the level of source discrimination decreases as the catchment size increases, probably due to heterogeneous geology and pedology, intra-source variability and to source overlap. Nevertheless, in the studied medium-sized catchments (ranging from 19.4 to 247 km 2), colour could differentiate between topsoil and sub-surface (i.e. channel bank) material and/or up to three sources types. No single colour model had discrimination power across catchments, instead in each catchment a different combination of colour parameters gathered from different colour space models produced optimal discrimination of potential sediment sources. Furthermore, a colour-based fingerprinting approach did not possess potential for integrating spatial provenance and source type information because colour parameters could not discriminate between contrasting geological sub-areas. In summary, although colour parameters were not capable of discriminating the range of land-use type and channel banks as potential suspended sediment sources in medium-sized catchments, they afford substantial information and could be integrated into the classical fingerprinting approach together with other constituents (e.g. geochemistry, radionuclides and/or organic compounds).

Martínez-Carreras, Núria; Krein, Andreas; Gallart, Francesc; Iffly, Jean F.; Pfister, Laurent; Hoffmann, Lucien; Owens, Philip N.

2010-05-01

21

Colour contribution to children's wayfinding in school environments  

Microsoft Academic Search

The purpose of this study was to explore the contribution of colour to children's wayfinding ability in school environments and to examine the differences between colours in terms of their remembrance and usability in route learning process. The experiment was conducted with three different sample groups for each of three experiment sets differentiated by their colour arrangement. The participants totalled

Nilgün Olguntürk

2011-01-01

22

Planetary nebula or symbiotic Mira? Near infrared colours mark the difference  

E-print Network

Nebulae around symbiotic Miras look very much like genuine planetary nebulae, although they are formed in a slightly different way. We present near infrared photometry of known and suspected symbiotic nebulae obtained with the Deep Near Infrared Southern Sky Survey (DENIS). We demonstrate that the near infrared colours are an excellent tool to distinguish symbiotic from genuine planetary nebulae. In particular we find that the bipolar planetary nebulae M 2-9 and Mz 3 are in fact symbiotic Miras. Further observations on prototype symbiotic Miras prove that the proposed classification scheme works generally.

S. Schmeja; S. Kimeswenger

2001-08-21

23

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

PubMed

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

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

2013-12-01

24

Effect of high pressure high temperature processing on the volatile fraction of differently coloured carrots.  

PubMed

To get deeper insight into the effect of high pressure high temperature (HPHT) processing on the volatile fraction of carrots, differently coloured cultivars exhibiting orange, purple, red and yellow hues were investigated. The impact of HPHT sterilisation was compared with thermal sterilisation based on equivalent microbiological inactivation. The results of this study demonstrated HPHT sterilisation to exert a distinct effect on important chemical reactions in comparison to thermal sterilisation. A comprehensive integration of MS-based metabolomic fingerprinting (HS-SPME-GC-MS) and chemometric tools has been implemented as an untargeted multivariate screening tool to identify differences. In all carrot cultivars, two dominant discriminative quality-related reactions were found: oxidative degradation and the Maillard reaction. Regarding the first reaction, oxidative terpenes, free fatty acids and carotenoids degradation products were detected at higher levels after HPHT sterilisation. Regarding the latter reaction, HPHT sterilisation appeared to suppress the formation of Maillard and Strecker degradation products. PMID:24491739

Kebede, Biniam T; Grauwet, Tara; Palmers, Stijn; Vervoort, Liesbeth; Carle, Reinhold; Hendrickx, Marc; Van Loey, Ann

2014-06-15

25

Anti-oxidative analysis, and identification and quantification of anthocyanin pigments in different coloured rice.  

PubMed

Anthocyanin pigments in coloured rice cultivars were isolated and identified using high-performance liquid chromatography techniques. Two black rice cultivars (Asamurasaki, Okunomurasaki) contained three major anthocyanins: cyanidin-3-glucoside, peonidin-3-glucoside and malvidin. Chinakuromai (black) rice additionally contained a fourth anthocyanin, petunidin-3-glucoside. Four red rice cultivars contained only malvidin. The total anthocyanin content varied greatly among black rice cultivars (79.5-473.7 mg/100g), but was lower in red rice (7.9-34.4 mg/100g). Total phenolic content was similar between red (460.32-725.69 mg/100g) and black (417.11-687.24 mg/100g) rice. The oxygen radical absorbing capacity was ranked as follows: red (69.91-130.32 ?mol Trolox/g)>black (55.49-64.85 ?mol Trolox/g)>green (35.32 ?mol Trolox/g)>white (21.81 ?mol Trolox/g) rice. The antioxidant capacity resulted mainly from the seed capsule, not the endosperm. The anthocyanin pigments contributed little to the total antioxidant capacity of red (0.03-0.1%) and black (0.5-2.5%) rice cultivars. Hence, the antioxidant capacity is derived mainly from other phenolic compounds. PMID:22980872

Chen, Xiao Qiong; Nagao, Norio; Itani, Tomio; Irifune, Kohei

2012-12-15

26

Colour analysis and verification of CCTV images under different lighting conditions  

NASA Astrophysics Data System (ADS)

Colour information is not faithfully maintained by a CCTV imaging chain. Since colour can play an important role in identifying objects it is beneficial to be able to account accurately for changes to colour introduced by components in the chain. With this information it will be possible for law enforcement agencies and others to work back along the imaging chain to extract accurate colour information from CCTV recordings. A typical CCTV system has an imaging chain that may consist of scene, camera, compression, recording media and display. The response of each of these stages to colour scene information was characterised by measuring its response to a known input. The main variables that affect colour within a scene are illumination and the colour, orientation and texture of objects. The effects of illumination on the appearance of colour of a variety of test targets were tested using laboratory-based lighting, street lighting, car headlights and artificial daylight. A range of typical cameras used in CCTV applications, common compression schemes and representative displays were also characterised.

Smith, R. A.; MacLennan-Brown, K.; Tighe, J. F.; Cohen, N.; Triantaphillidou, S.; MacDonald, L. W.

2008-01-01

27

Colour stability and vitamin C retention of roselle juice (Hibiscus sabdariffa L) in different packaging materials  

Microsoft Academic Search

Purpose – In Nigeria, roselle juice is quite popular among the populace presumably owing to its attractive colour, pleasant flavour and nutritional attributes. In the citrus industry, processing and packing material selection have significant effect on quality of juice product during storage. The effects of packaging materials, and storage temperature on colour and vitamin C retention of sobo juice extracted

J. O. Aina; A. A. Shodipe

2006-01-01

28

Colour of normal and high pH beef heated to different temperatures as related to oxygenation.  

PubMed

The effects of oxygenation and thermal treatment (internal temperature, T(i): 45, 60, 75°C) on the colour and some colour related physical and biochemical properties of beef longissimus dorsi (LD) muscle, both normal (pH(u)?5.6) and DFD (pH(u)>6.6), were studied. The colour components (L (?), a (?), b (?) values) for the raw and heated LD, both before and after oxygenation, were instrumentally and sensorily evaluated. The colour of raw and heated (60°C) DFD beef before and after oxygenation differed significantly from the normal meat and contained more native muscle pigment (TMP). pH also influenced the depth of the oxygenated layer, specific activity of cytochrome c oxidase (SACCO) and the amount of oxygen consumed. An increase in internal temperature was usually accompanied by a lower SACCO and a significant decrease of TMP, as well as a change of all colour parameters. Oxygenation of the raw and heated slices (except at 75°C) of both types of meat led to higher L (?), a (?) and b (?) values. PMID:22060797

Gašperlin, L; Zlender, B; Abram, V

2000-04-01

29

Multiple coloured ornaments in male common kestrels: different mechanisms to convey quality  

NASA Astrophysics Data System (ADS)

The simultaneous exhibition of more than one secondary sexual trait is a widespread phenomenon in nature, though it has rarely been explored. It has been proposed that different ornaments may convey complementary or back-up information about a single aspect of individual quality (redundancy hypothesis) or that each ornament may convey unique information (multiple-messages hypothesis). During a 5-year period, we measured several carotenoid-based (eye ring, bill cere and tarsi skin) and melanin-based (head, back, rump and tail feathers) potential ornamental colours in male common kestrels. We analysed whether multiple ornaments can convey different or related information about individual quality. We explored whether different ornaments can express different information depending on the pigment (carotenoids or melanins), the time-scale over which the ornament can change (dynamic vs. static) and the season of the year when the ornament is formed. We found that both melanin- and carotenoid- based traits correlated with indexes of quality, including body condition, body condition of their partners and laying date. However, not all ornaments correlated with the same measures of quality. In addition, some ornaments were intercorrelated within the same individuals while others were not. These results suggest that different ornaments can convey information about different qualities, as predicted by the multiple-messages hypothesis. In addition, this study suggests that the predominant pigment (e.g. carotenoid vs. melanin, eumelanin vs. pheomelanin), the time-scale over which the trait is developed (static feathers vs. dynamic skin) and the season of the year at which the ornament is produced can be potential mechanisms to convey different messages in male common kestrels.

Vergara, Pablo; Fargallo, Juan A.

2011-04-01

30

Colonization of natural substrata of different roughness and colour by Ephemeroptera nymphs using retrieval and direct observation techniques  

Microsoft Academic Search

We investigated the colonization of stream substrata by Ephemeroptera nymphs in a Canadian Rocky Mountain stream. Stream substrata used in our study were different textures (smooth and rough) and colours (dark and light); the taxonomic groups studied were Drunella coloradensis Dodds (Ephemerellidae), Heptageniidae (Cinygmula and Epeorus) and a Baetis Ameletus group (Baetidae and Siphlonuridae). We tested the hypothesis that as

Richard J. Casey; Hugh F. Clifford

1989-01-01

31

The Tooth and Skin Colour Interrelationship across the Different Ethnic Groups  

PubMed Central

Objectives. The purpose of the study was to investigate the relation between skin and tooth colour parameters in various ethnic groups. Materials and Methods. Saudi Arabian, Indian, African, and East Asian ethnic groups of 75 each were included in the study. The tooth colour was determined by spectrophotometer in CIELAB parameters. The skin colour was measured at earlobe, forehead, and malar locations by clinical skin photography. The data was statistically analysed by one-way ANOVA and correlation tests. Results. The “L” vale for the Saudi Arabian group had a strong correlation at earlobe location (r = 0.275), while correlation was found at forehead (r = 0.271) and malar region (r = 0.261) with Indian ethnic group. A strong negative correlation was observed in African ethnic group at all three locations for “L” parameter. The redness value “a” is found to have strong negative linear correlation between the earlobe and tooth for Saudi Arabian (r = ?0.240) and Indian ethnic groups (r = ?0.268). The “b” showed no correlation with skin location in all groups except positive correlation in African ethnic groups. Conclusions. The strong correlation was found between the skin and tooth colour parameters; hence the skin colour can be used as a guide for artificial tooth selection in edentulous patients. PMID:25101125

Haralur, Satheesh B.; Dibas, Ahmed Mohammed; Almelhi, Nabil Abdullah; Al-Qahtani, Dhafer Ali

2014-01-01

32

Genetics of eye colours in different rural populations on the Silk Road.  

PubMed

Eye colour is a highly transmissible and discernible trait in humans. A genome-wide association scan for variants associated to eye pigmentation was carried out on a large group of individuals coming from the Silk Road. Significant associations were detected not only with HERC2 (P-value=4.99 × 10(-37)) and OCA2 (P-value=4.51 × 10(-9)) genes but also with CTNNA2 gene (P-value=4.06 × 10(-8)). Moreover, the multifactor dimensionality reduction analysis clearly showed the effect of HERC2 haplotype over OCA2 mostly associated with SNP, thus enabling a highly accurate eye-colour prediction. Finally, the regression tree analysis showed that individuals carrying a given combination of haplotypes have a significant probability to show a blue or green/grey iris colour as compared with brown, with a gradient from west to east. PMID:23486544

Ulivi, Sheila; Mezzavilla, Massimo; Gasparini, Paolo

2013-11-01

33

Genetics of eye colours in different rural populations on the Silk Road  

PubMed Central

Eye colour is a highly transmissible and discernible trait in humans. A genome-wide association scan for variants associated to eye pigmentation was carried out on a large group of individuals coming from the Silk Road. Significant associations were detected not only with HERC2 (P-value=4.99 × 10?37) and OCA2 (P-value=4.51 × 10?9) genes but also with CTNNA2 gene (P-value=4.06 × 10?8). Moreover, the multifactor dimensionality reduction analysis clearly showed the effect of HERC2 haplotype over OCA2 mostly associated with SNP, thus enabling a highly accurate eye-colour prediction. Finally, the regression tree analysis showed that individuals carrying a given combination of haplotypes have a significant probability to show a blue or green/grey iris colour as compared with brown, with a gradient from west to east. PMID:23486544

Ulivi, Sheila; Mezzavilla, Massimo; Gasparini, Paolo

2013-01-01

34

Colour and antioxidant capacity stability in grape, strawberry and plum peel model juices at different pHs and temperatures.  

PubMed

The aim of the study was to evaluate the anthocyanin sources potential as natural food colouring. Model juices (MJs) of grape, strawberry and plum peel were stored during 8weeks in darkness at 6 and 23°C. The colour stability was evaluated at pH 2.4, 3.1, 4.0, 5.0, 6.0, 7.0 and 8.1, and the antioxidant capacity at pH 4.0. The plum peel MJ showed the best and more stable colour parameters. The grape MJs presented a high stability although the chroma values were very low. The storage of strawberry MJ demonstrated a low stability at 23°C. The vitamin C equivalent antioxidant capacity in grape, strawberry and plum peel MJs was 7, 40 and 50mg/L, respectively. The strawberry MJ stability was very low. Total phenolics and anthocyanins ranged between 18-101 and 2-62mg/L of MJ, respectively. The determination coefficient was R(2)=0.745 between the antioxidant capacity and total phenolics. PMID:24518333

Hernández-Herrero, J A; Frutos, M J

2014-07-01

35

Modelling colour and chlorophyll losses of frozen green beans ( Phaseolus vulgaris, L.)  

Microsoft Academic Search

Colour changes and chlorophyll degradation of frozen green beans (Phaseolus vulgaris, L., variety bencanta) were studied during 250 days of storage at ?7, ?15 and ?30 °C. Chlorophyll a and b losses and colour Hunter a and b co-ordinates and total colour difference (TCDH) changes were successfully described by first order and reversible first order models, respectively. The temperature effect was

R. C. Martins; C. L. M. Silva

2002-01-01

36

Missense and nonsense mutations in melanocortin 1 receptor (MC1R) gene of different goat breeds: association with red and black coat colour phenotypes but with unexpected evidences  

Microsoft Academic Search

BACKGROUND: Agouti and Extension loci control the relative amount of eumelanin and pheomelanin production in melanocytes that, in turn, affects pigmentation of skin and hair. The Extension locus encodes the melanocortin 1 receptor (MC1R) whose permanent activation, caused by functional mutations, results in black coat colour, whereas other inactivating mutations cause red coat colour in different mammals. RESULTS: The whole

Luca Fontanesi; Francesca Beretti; Valentina Riggio; Stefania Dall'Olio; Elena Gómez González; Raffaella Finocchiaro; Roberta Davoli; Vincenzo Russo; Baldassare Portolano

2009-01-01

37

Is colour cognitive?  

NASA Astrophysics Data System (ADS)

In recent years, colour-vision abilities have been rather generously ascribed to various invertebrates and even bacteria. This uncertainty of when to diagnose colour vision stems in part from confusing what colour vision can do with what it is. What colour vision can do is discriminate wavelength independent of intensity. However, if we take this as a definition of what colour vision is, then we might be obliged to conclude that some plants and bacteria have colour vision. Moreover, there is a similar confusion of what are necessary and what are sufficient mechanisms and behavioural abilities for colour vision. To humans, seeing in colour means seeing an image in which objects/lights have chromatic attributes—in contrast to the sensation that we have when viewing monochrome movies, or our experience in dim light when only rod vision is possible. The necessary basic equipment for this is to have at least two types of photoreceptors that differ in spectral sensitivity, and at least one type of spectrally opponent cell to compare the signals from the photoreceptors. Clearly, however, a necessary additional prerequisite for colour vision is to have vision, which entails the identification of shapes, sizes and locations of objects in the world. Thus, if an animal has colour vision, it should see an image in which distinct objects/lights have colour attributes. This distinguishes colour vision from wavelength discrimination, but also from what has historically been called wavelength-specific behaviour: a type of behaviour triggered by fixed configurations of spectral receptor signals; however, we discuss difficulties in diagnosing wavelength-specific behaviour as an indicator of the absence of colour vision. Finally, we discuss whether colour vision, by definition, contains a cognitive dimension for ordering and classifying perceptual experience.

Skorupski, Peter; Chittka, Lars

2011-03-01

38

Shelf-life and colour change kinetics of Aloe vera gel powder under accelerated storage in three different packaging materials.  

PubMed

Aloe vera gel powder was produced through dehumidified air drying of Aloe vere gel at optimized conditions of temperature, relative humidity and air velocity of 64 °C, 18% and 0.8 m.s(-1), respectively. The powder was packed in three different packaging materials viz., laminated aluminum foil (AF), biaxially oriented polypropylene (BOPP) and polypropylene (PP). The shelf-life of the powder was predicted on the basis of free flowness of product under accelerated storage condition (38?±?1 °C, 90?±?1% relative humidity) and was calculated to be 33.87, 42.58 and 51.05 days in BOPP, PP and AF, respectively. The storage stability of powder in terms of colour change was studied. The magnitude of colour change of Aloe vera gel powder during storage suggests that AF was better than BOPP and PP. The colour change of powder during storage followed first order reaction kinetics with a rate constant of 0.0444 per day for AF, 0.075 per day for BOPP and 0.0498 per day for PP. PMID:24425977

Ramachandra, C T; Rao, P Srinivasa

2013-08-01

39

Why birds eat colourful grit: colour preferences revealed by the colour of gizzard stones.  

PubMed

Colour preferences from sexual or social contexts are assumed to have arisen owing to preferences for specific kinds of food, representing a sensory bias, but once colour preferences have evolved in a sexual context, they may also be expressed during foraging. We tested whether preferences for specific body colours (i.e. plumage and soft parts) were related to colour preferences for grit ingested by birds. Birds eat grit to facilitate break down of food by the gizzard, and this function is independent of the colour of grit, but depends on the physical properties of stones. Bird species were significantly consistent in colour of grit, and grit of different colours varied in prevalence among species, even when analyses were restricted to a sample from a single locality. There were positive correlations between presence of lilac and red grit in the gizzard and presence of sexually dichromatic lilac and red colour on the body. There was a positive correlation between red grit colour and red sexually monochromatic body colour. Bird species with many different sexual colours, but not sexually monochromatic colours on their body had many different colours of grit. Males had more lilac and red grit than females, with this effect differing among species, whereas that was not the case for grit of other colours. These findings are consistent with the sensory bias hypothesis that birds express preferences for grit of specific colours and a high diversity of colours related to sexual colouration of the body, even when the colour of such grit is only visible to the individual at the moment of ingestion. PMID:20050966

Møller, A P; Erritzøe, J

2010-03-01

40

Colour contribution to children's wayfinding in school environments  

NASA Astrophysics Data System (ADS)

The purpose of this study was to explore the contribution of colour to children's wayfinding ability in school environments and to examine the differences between colours in terms of their remembrance and usability in route learning process. The experiment was conducted with three different sample groups for each of three experiment sets differentiated by their colour arrangement. The participants totalled 100 primary school children aged seven and eight years old. The study was conducted in four phases. In the first phase, the participants were tested for familiarity with the experiment site and also for colour vision deficiencies by using Ishihara's tests for colour-blindness. In the second phase, they were escorted on the experiment route by the tester one by one, from one starting point to one end point and were asked to lead the tester to the end point by the same route. In the third phase, they were asked to describe verbally the route. In the final phase, they were asked to remember the specific colours at their correct locations. It was found that colour has a significant effect on children's wayfinding performances in school environments. However, there were no differences between different colours in terms of their remembrances in route finding tasks. In addition, the correct identifications of specific colours and landmarks were dependent on their specific locations. Contrary to the literature, gender differences were not found to be significant in the accuracy of route learning performances.

Helvac?o?lu, Elif; Olguntürk, Nilgün

2011-03-01

41

Assessment of different colour parameters for discriminating potential suspended sediment sources and provenance: A multi-scale study in Luxembourg  

Microsoft Academic Search

Sediment colour has recently been used successfully to estimate suspended sediment sources in small catchments using the fingerprinting approach. The methodology offers opportunity for further research since it provides a rapid and cheap means for investigating sediment sources. However, the colour-based fingerprinting approach has not yet been tested in medium and large catchments. This paper aims to test whether colour

Núria Martínez-Carreras; Andreas Krein; Francesc Gallart; Jean F. Iffly; Laurent Pfister; Lucien Hoffmann; Philip N. Owens

2010-01-01

42

Daily behaviour can differ between colour morphs of the same species: a study on circadian activity behaviour of grey and pied zebra finches.  

PubMed

To investigate if the plumage colour mutation relates to circadian activity behaviour in the zebra finch, Taeniopygia guttata, wild type grey and pied mutant males were sequentially subjected for three weeks each to 12 h light:12 h darkness (12L:12D) and constant dim light (LL(dim)) condition. During the first 3 h of the 12 h day, pied finches were significantly greater active than grey finches. Also, as compared to grey, pied finches had longer activity duration in the day, with early activity onsets and late activity offsets. This was changed under free-running condition (LL(dim)), when the activity later in the subjective day (clock hour 9 and 11) was significantly greater in grey than in pied finches.Two colour morphs differed in daily activity profile, but not in the total daily activity or circadian rhythm period. Results suggest that greyzebra finches represent late chronotype, and could perhaps be better adapted to a seemingly stressful environment, such as low intensity LL(dim) in the present study. PMID:24851415

Mishra, Ila; Trivedi, Amit Kumar; Kumar, Vinod

2014-05-01

43

The Four-Colour Theorem  

Microsoft Academic Search

The four-colour theorem, that every loopless planar graph admits a vertex-colouring with at most four different colours, was proved in 1976 by Appel and Haken, using a computer. Here we give another proof, still using a computer, but simpler than Appel and Haken's in several respects.

Neil Robertson; Daniel P. Sanders; Paul D. Seymour; Robin Thomas

1997-01-01

44

Coloured solutions of equations in finite groups  

Microsoft Academic Search

In this article, we consider the relations between colourings and some equations in finite groups. We will express relations linking the numbers of the differently coloured solutions of an equation that depend only on the cardinality of the colouring and not on the distribution of the colours. This gives a link between Ramsey theory that investigates the existence of monochromatic

Éric Balandraud

2007-01-01

45

Hyperbolic geometry for colour metrics.  

PubMed

It is well established from both colour difference and colour order perpectives that the colour space cannot be Euclidean. In spite of this, most colour spaces still in use today are Euclidean, and the best Euclidean colour metrics are performing comparably to state-of-the-art non-Euclidean metrics. In this paper, it is shown that a transformation from Euclidean to hyperbolic geometry (i.e., constant negative curvature) for the chromatic plane can significantly improve the performance of Euclidean colour metrics to the point where they are statistically significantly better than state-of-the-art non-Euclidean metrics on standard data sets. The resulting hyperbolic geometry nicely models both qualitatively and quantitatively the hue super-importance phenomenon observed in colour order systems. PMID:24921355

Farup, Ivar

2014-05-19

46

Colour and carotenoid changes of pasteurised orange juice during storage.  

PubMed

The correlation of carotenoid changes with colour degradation of pasteurised single strength orange juice was investigated at 20, 28, 35 and 42°C for a total of 32weeks of storage. Changes in colour were assessed using the CIELAB system and were kinetically described by a zero-order model. L(?), a(?), b(?), ?E(?), Cab(?) and hab were significantly changed during storage (p<0.05). Activation energies for all colour parameters were 64-73kJmol(-1). Several carotenoids showed important changes and appeared to have different susceptibilities to storage. A decrease of ?-cryptoxanthin was observed at higher temperatures, whereas antheraxanthin started to decrease at lower temperatures. Depending on the time and temperature, changes in carotenoids could be due to isomerisation reactions, which may lead to a perceptible colour change. Although the contribution of carotenoids was recognised to some extent, other reactions seem of major importance for colour degradation of orange juice during storage. PMID:25308677

Wibowo, Scheling; Vervoort, Liesbeth; Tomic, Jovana; Santiago, Jihan Santanina; Lemmens, Lien; Panozzo, Agnese; Grauwet, Tara; Hendrickx, Marc; Van Loey, Ann

2015-03-15

47

Colour measurements of surfaces to evaluate the restoration materials  

NASA Astrophysics Data System (ADS)

In this paper two case studies on the application of colour measurements for the evaluation of some restoration materials are discussed. The materials related to the research are: watercolours employed in restoration of wall paintings and preservative/consolidants for wood artifacts. Commercial watercolours, supplied by Maimeri, Windsor&Newton and Talens factories have been tested. Colour measurements have been performed by means of a reflectance spectrophotometer (RS) before and after accelerated ageing of watercolours at 92% relative humidity (RH) and in a Solar Box chamber. The experimental results show that watercolours based on natural earths and artificial ultramarine undergo the main colour changes, expressed as L*, a* and b* variations and total colour difference (?E*). In the other cases colour differences depend on both watercolour typology and suppliers. The other example concerns the evaluation of colour change due to surface treatment of Poplar (Populus sp.) and chestnut (Castanea sativa L.) wood samples. The wooden samples have been treated with a novel organic preservative/consolidant product that has been tested also in a real case as comparison. The treated samples have been artificially aged in Solar Box chamber equipped with a 280 nm UV filter. Colour has been measured before and after the artificial ageing by means of a RS. Colour changes have been determined also for the main door of an historical mansion in Viterbo, made of chestnut wood, and exposed outdoors.

Lo Monaco, Angela; Marabelli, Maurizio; Pelosi, Claudia; Picchio, Rodolfo

2011-06-01

48

Fecundity selection on ornamental plumage colour differs between ages and sexes and varies over small spatial scales.  

PubMed

Avian plumage colours are some of the most conspicuous sexual ornaments, and yet standardized selection gradients for plumage colour have rarely been quantified. We examined patterns of fecundity selection on plumage colour in blue tits (Cyanistes caeruleus L.). When not accounting for environmental heterogeneity, we detected relatively few cases of selection. We found significant disruptive selection on adult male crown colour and yearling female chest colour and marginally nonsignificant positive linear selection on adult female crown colour. We discovered no new significant selection gradients with canonical rotation of the matrix of nonlinear selection. Next, using a long-term data set, we identified territory-level environmental variables that predicted fecundity to determine whether these variables influenced patterns of plumage selection. The first of these variables, the density of oaks within 50 m of the nest, influenced selection gradients only for yearling males. The second variable, an inverse function of nesting density, interacted with a subset of plumage selection gradients for yearling males and adult females, although the strength and direction of selection did not vary predictably with population density across these analyses. Overall, fecundity selection on plumage colour in blue tits appeared rare and inconsistent among sexes and age classes. PMID:21585583

Parker, T H; Wilkin, T A; Barr, I R; Sheldon, B C; Rowe, L; Griffith, S C

2011-07-01

49

3-facial colouring of plane graphs  

Microsoft Academic Search

A plane graph is l-facially k-colourable if its vertices can be coloured with\\u000ak colours such that any two distinct vertices on a facial segment of length at\\u000amost l are coloured differently. We prove that every plane graph is 3-facially\\u000a11-colourable. As a consequence, we derive that every 2-connected plane graph\\u000awith maximum face-size at most 7 is cyclically

Frédéric Havet; Jean-Sébastien Sereni; Riste Skrekovski

2006-01-01

50

Pitfalls in colour photography of choroidal tumours.  

PubMed

Colour imaging of fundus tumours has been transformed by the development of digital and confocal scanning laser photography. These advances provide numerous benefits, such as panoramic images, increased contrast, non-contact wide-angle imaging, non-mydriatic photography, and simultaneous angiography. False tumour colour representation can, however, cause serious diagnostic errors. Large choroidal tumours can be totally invisible on angiography. Pseudogrowth can occur because of artefacts caused by different methods of fundus illumination, movement of reference blood vessels, and flattening of Bruch's membrane and sclera when tumour regression occurs. Awareness of these pitfalls should prevent the clinician from misdiagnosing tumours and wrongfully concluding that a tumour has grown. PMID:23238442

Schalenbourg, A; Zografos, L

2013-02-01

51

The colour-differences in Epipactis helleborine (L.) Cr. Wats. & Coult., and the selection of the genetical varieties by environment  

Microsoft Academic Search

Summary It was found that climatological environmental influences play an important rôle in the natural selection of the colour-varieties ofEpipactis helleborine (L)Cr., Wats. & Coult. on the island of Ameland (Netherlands.)

J. Weijer

1953-01-01

52

Exploring the Differences and Similarities Between Black\\/African and Coloured Men Regarding Violence Against Women, Substance Abuse, and HIV Risks in Cape Town, South Africa  

Microsoft Academic Search

Existing research often reports HIV risks, men's relationships with women, substance abuse, and violence among Black\\/African and Coloured men in Cape Town, South Africa, without making note of possible cultural distinctions. Because of apartheid, race has historically affected the social and economic circumstances of many men differently; therefore, our research aimed to explore cultural nuances as they relate to HIV

Kyla M. Sawyer-Kurian; Wendee M. Wechsberg; Winnie K. Luseno

2009-01-01

53

Multiple coloured ornaments in male common kestrels: different mechanisms to convey quality  

Microsoft Academic Search

The simultaneous exhibition of more than one secondary sexual trait is a widespread phenomenon in nature, though it has rarely\\u000a been explored. It has been proposed that different ornaments may convey complementary or back-up information about a single\\u000a aspect of individual quality (redundancy hypothesis) or that each ornament may convey unique information (multiple-messages\\u000a hypothesis). During a 5-year period, we measured

Pablo Vergara; Juan A. Fargallo

2011-01-01

54

Colour detection thresholds in faces and colour patches.  

PubMed

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. PMID:24344549

Tan, Kok Wei; Stephen, Ian D

2013-01-01

55

Colour vision requirements of firefighters.  

PubMed

To perform their job safely firefighters must be able to identify colours on industrial gas cylinders, portable fire extinguishers, road traffic signals and several pieces of firefighting equipment. Although good colour vision is necessary we believe that the existing colour vision standard, which bars entry to the fire service to applicants who fail more than two plates of the Ishihara test, is unnecessarily stringent. We have identified and quantified the colour coded information encountered by firefighters. Colours were plotted on the CIE chromaticity diagram (1931) and isochromatic zones, which document the colour confusions of colour deficient observers, superimposed. This novel technique established possible colour confusions in different types of colour deficiency. Analysis of the results showed that red/green dichromats (protanopes and deuteranopes), severe deuteranomalous trichromats who fail the Farnsworth D15 test, and protanomalous trichromats are unsuitable for firefighting work. However, people with slight deuteranomalous trichromatism who pass the D15 test, are not disadvantaged and can be employed safely as firefighters. A new colour vision standard and a new testing procedure is recommended. PMID:8776247

Margrain, T H; Birch, J; Owen, C G

1996-04-01

56

The colours of the Sun  

NASA Astrophysics Data System (ADS)

We compile a sample of Sun-like stars with accurate effective temperatures, metallicities and colours (from the ultraviolet to the near-infrared). A crucial improvement is that the effective temperature scale of the stars has recently been established as both accurate and precise through direct measurement of angular diameters obtained with stellar interferometers. We fit the colours as a function of effective temperature and metallicity, and derive colour estimates for the Sun in the Johnson-Cousins, Tycho, Strömgren, 2MASS and SDSS photometric systems. For (B-V)solar, we favour the `red' colour 0.64 versus the `blue' colour 0.62 of other recent papers, but both values are consistent within the errors; we ascribe the difference to the selection of Sun-like stars versus interpolation of wider colour-Teff-metallicity relations.

Holmberg, Johan; Flynn, Chris; Portinari, Laura

2006-04-01

57

The colours of the Sun  

E-print Network

We compile a sample of Sun-like stars with accurate effective temperatures, metallicities and colours (from the UV to the near-IR). A crucial improvement is that the effective temperature scale of the stars has recently been established as both accurate and precise through direct measurement of angular diameters obtained with stellar interferometers. We fit the colours as a function of effective temperature and metallicity, and derive colour estimates for the Sun in the Johnson/Cousins, Tycho, Stromgren, 2MASS and SDSS photometric systems. For (B-V)_Sun, we favour the ``red'' colour 0.64 versus the ``blue'' colour 0.62 of other recent papers, but both values are consistent within the errors; we ascribe the difference to the selection of Sun-like stars versus interpolation of wider colour-Teff-metallicity relations.

Johan Holmberg; Chris Flynn; Laura Portinari

2005-11-06

58

Disruptive Colouration and Perceptual Grouping  

PubMed Central

Camouflage is the primary defence of many animals and includes multiple strategies that interfere with figure-ground segmentation and object recognition. While matching background colours and textures is widespread and conceptually straightforward, less well explored are the optical ‘tricks’, collectively called disruptive colouration, that exploit perceptual grouping mechanisms. Adjacent high contrast colours create false edges, but this is not sufficient for an object’s shape to be broken up; some colours must blend with the background. We test the novel hypothesis that this will be particularly effective when the colour patches on the animal appear to belong to, not merely different background colours, but different background objects. We used computer-based experiments where human participants had to find cryptic targets on artificial backgrounds. Creating what appeared to be bi-coloured foreground objects on bi-coloured backgrounds, we generated colour boundaries that had identical local contrast but either lay within or between (illusory) objects. As predicted, error rates for targets matching what appeared to be different background objects were higher than for targets which had otherwise identical local contrast to the background but appeared to belong to single background objects. This provides evidence for disruptive colouration interfering with higher-level feature integration in addition to previously demonstrated low-level effects involving contour detection. In addition, detection was impeded in treatments where targets were on or in close proximity to multiple background colour or tone boundaries. This is consistent with other studies which show a deleterious influence of visual ‘clutter’ or background complexity on search. PMID:24466337

Espinosa, Irene; Cuthill, Innes C.

2014-01-01

59

Microstructure and bioaccessibility of different carotenoid species as affected by high pressure homogenisation: a case study on differently coloured tomatoes.  

PubMed

The effect of high pressure homogenisation (HPH) on structure (Bostwick consistency, particle size distribution and microstructure) and carotenoid in vitro bioaccessibility of different tomato pulps was investigated. HPH decreased tomato particle size due to matrix disruption and increased product consistency, probably due to the formation of a fibre network. Homogenisation also resulted in a decrease of in vitro bioaccessibility of lycopene, ?-carotene, and lutein. Such decrease was attributed to the structuring effect of HPH. An inverse relation between tomato consistency and carotenoid in vitro bioaccessibility was found. This dependency was affected by carotenoid species and its localisation within the matrix. It could be observed that one matrix (e.g. (homogenised) red tomato pulp) can contain carotenoids with a very low bioaccessibility (lycopene) as well as carotenoids with a very high bioaccessibility (lutein), indicating that carotenoid bioaccessibility is not solely dependent on the matrix. PMID:23993590

Panozzo, Agnese; Lemmens, Lien; Van Loey, Ann; Manzocco, Lara; Nicoli, Maria Cristina; Hendrickx, Marc

2013-12-15

60

Changes in texture, colour and fatty acid composition of male and female pig shoulder fat due to different dietary fat sources.  

PubMed

Two experiments with 72 slaughter pigs in each were conducted. Entire males and females were individually fed restricted. Palm kernel-, soybean- and fish-oil were used in varying combinations, giving different dietary fat levels (29-80g/kg) and iodine values ranging from 50 to 131. Shoulder fat was analysed for fatty acid composition (inner and outer layer), firmness and colour. A clear dose-response relationship was seen between fatty acids in diets and in shoulder fat. Interestingly, the very long chain n-3 fatty acids seemed to be deposited more efficiently when additional fat was included in the diet. Both high and low dietary iodine values changed towards less extreme iodine values in fat. Low-fat diets enhanced de novo synthesis of fatty acids. Males revealed a higher percentage of PUFA and a lower percentage of C18:1 and MUFA. Fat firmness, but not colour, was influenced by sex and dietary fat source. PMID:22112523

Hallenstvedt, E; Kjos, N P; Overland, M; Thomassen, M

2012-03-01

61

An RGB Approach to Prismatic Colours  

ERIC Educational Resources Information Center

Teaching prismatic colours usually boils down to establishing the take-home message that white light consists of "differently refrangible" coloured rays. This approach explains the classical spectrum of seven colours but has its limitations, e.g. in discussing spectra from setups with higher resolution or in understanding the well…

Theilmann, Florian; Grusche, Sascha

2013-01-01

62

Different effects of alcohol on automatic detection of colour, location and time change: A mismatch negativity study.  

PubMed

The effects of alcohol on pre-attentive processing have been well studied in the past decades. However, the majority of studies focus on pre-attentive auditory processing and only a few studies have examined the effects of alcohol on visual processing. This study investigates the effects of alcohol on automatic pre-attentive processing of visual changes in colour, location and duration. We compared the mean amplitudes and the amplitude decline ratios of visual mismatch negativity (vMMN) responses elicited for small and large changes in image colour, location and duration in 12 individuals under the influence of alcohol and in a placebo condition. The vMMN amplitudes for changes in location and duration significantly decreased in the alcohol condition as compared with the placebo condition, and the magnitude of decrease was not related to the magnitude of change in the deviant stimuli. However, the amplitude of colour vMMN, in the alcohol condition, did not change significantly compared to the placebo condition. These results show that pre-attentive visual processing is impaired by alcohol, and that this impairment may be feature-specific. In addition, this impairment was not related to the magnitude of stimuli change. PMID:25237124

He, Jinbo; Hu, Yue; Pakarinen, Satu; Li, Bingbing; Zhou, Zongkui

2014-12-01

63

Primary posterior stabilized total knee arthroplasty: analysis of different instrumentation  

PubMed Central

Background Intercondylar femoral bone removal during posterior stabilized (PS) total knee arthroplasty (TKA) makes many cruciate substituting implant designs less appealing than cruciate retaining implants. Bone stock conservation is considered fundamental in the prevision of future revision surgeries. The purpose of this study was to compare the quantity of intercondylar bone removable during PS housing preparation using three contemporary PS TKA instrumentations. Method We compared different box cutting jigs which were utilized for the PS housing of three popular PS knee prostheses. The bone removal area from every PS box cutting jig was three-dimensionally measured. Results Independently from the implant size, the cutting jig for a specific PS TKA always resected significantly less bone than the others: this difference was statistically significant, especially for small- to medium-sized total knee femoral components. Conclusion This study does not establish a clinical relevance of removing more or less bone at primary TKA, but suggests that if a PS design is indicated, it is preferable to select a model which possibly resects less distal femoral bone. PMID:25037275

2014-01-01

64

Colour Guided Colour Image Steganography  

E-print Network

Information security has become a cause of concern because of the electronic eavesdropping. Capacity, robustness and invisibility are important parameters in information hiding and are quite difficult to achieve in a single algorithm. This paper proposes a novel steganography technique for digital color image which achieves the purported targets. The professed methodology employs a complete random scheme for pixel selection and embedding of data. Of the three colour channels (Red, Green, Blue) in a given colour image, the least two significant bits of any one of the channels of the color image is used to channelize the embedding capacity of the remaining two channels. We have devised three approaches to achieve various levels of our desired targets. In the first approach, Red is the default guide but it results in localization of MSE in the remaining two channels, which makes it slightly vulnerable. In the second approach, user gets the liberty to select the guiding channel (Red, Green or Blue) to guide the r...

Amirtharajan, R; Swarup, Motamarri Abhilash; K, Mohamed Ashfaaq; Rayappan, John Bosco Balaguru

2010-01-01

65

Missense and nonsense mutations in melanocortin 1 receptor (MC1R) gene of different goat breeds: association with red and black coat colour phenotypes but with unexpected evidences  

PubMed Central

Background Agouti and Extension loci control the relative amount of eumelanin and pheomelanin production in melanocytes that, in turn, affects pigmentation of skin and hair. The Extension locus encodes the melanocortin 1 receptor (MC1R) whose permanent activation, caused by functional mutations, results in black coat colour, whereas other inactivating mutations cause red coat colour in different mammals. Results The whole coding region of the MC1R gene was sequenced in goats of six different breeds showing different coat colours (Girgentana, white cream with usually small red spots in the face; Maltese, white with black cheeks and ears; Derivata di Siria, solid red; Murciano-Granadina, solid black or solid brown; Camosciata delle Alpi, brown with black stripes; Saanen, white; F1 goats and the parental animals). Five single nucleotide polymorphisms (SNPs) were identified: one nonsense mutation (p.Q225X), three missense mutations (p.A81V, p.F250V, and p.C267W), and one silent mutation. The stop codon at position 225 should cause the production of a shorter MC1R protein whose functionality may be altered. These SNPs were investigated in a larger sample of animals belonging to the six breeds. The Girgentana breed was almost fixed for the p.225X allele. However, there was not complete association between the presence of red spots in the face and the presence of this allele in homozygous condition. The same allele was identified in the Derivata di Siria breed. However, its frequency was only 33%, despite the fact that these animals are completely red. The p.267W allele was present in all Murciano-Granadina black goats, whereas it was never identified in the brown ones. Moreover, the same substitution was present in almost all Maltese goats providing evidence of association between this mutation and black coat colour. Conclusion According to the results obtained in the investigated goat breeds, MC1R mutations may determine eumelanic and pheomelanic phenotypes. However, they are probably not the only factors. In particular, the surprising not complete association of the nonsense mutation (p.Q225X) with red coat colour raises a few hypotheses on the determination of pheomelanic phenotypes in goats that should be further investigated. PMID:19706191

2009-01-01

66

Molecular Characterisation of Colour Formation in the Prawn Fenneropenaeus merguiensis  

PubMed Central

Introduction Body colouration in animals can have a range of functions, with predator protection an important aspect of colour in crustaceans. Colour determination is associated with the carotenoid astaxanthin, which is taken up through the diet and stabilised in the tissues by the protein crustacyanin. As a variety of genes are found to play a role in colour formation in other systems, a holistic approach was employed in this study to determine the factors involved in Fenneropenaeus merguiensis colouration. Results Full length F. merguiensis crustacyanin subunit A and C sequences were isolated. Crustacyanin subunit A and C were found in the F. merguiensis transcriptomes of the muscle/cuticle tissue, hepatopancreas, eye stalk and nervous system, using 454 next generation sequencing technology. Custom microarray analysis of albino, light and dark F. merguiensis cuticle tissue showed genes encoding actin, sarcoplasmic calcium-binding protein and arginine kinase to be 4-fold or greater differentially expressed (p<0.05) and down-regulated in albinos when compared to light and dark samples. QPCR expression analysis of crustacyanin and total astaxanthin pigment extraction revealed significantly (p<0.05) lower crustacyanin subunit A and C gene transcript copy numbers and total astaxanthin levels in albinos than in the light and dark samples. Additionally, crustacyanin subunit A and C expression levels correlated positively with each other. Conclusions This study identified gene products putatively involved in crustacean colouration, such as crustacyanin, sarcoplasmic calcium-binding protein and forms of actin, and investigated differences in gene expression and astaxanthin levels between albino, light and dark coloured prawns. These genes open a path to enhance our understanding of the biology and regulation of colour formation. PMID:23441225

Ertl, Nicole G.; Elizur, Abigail; Brooks, Peter; Kuballa, Anna V.; Anderson, Trevor A.; Knibb, Wayne R.

2013-01-01

67

Significance of early postmortem temperature and pH decline on colour characteristics of pork loin from different crossbreeds.  

PubMed

The significance of early postmortem (pm) temperature and pH decline and the level of the muscle metabolites creatine phosphate (CP) and adenosine triphosphate (ATP) on the colour of porcine M. longissimus dorsi was studied in a factorially designed experiment. Two stress levels peri mortem (minimal stress vs treadmill exercise and electrical stunning of the pigs) and four genotypes (Duroc boars crossed with Landrace-Yorkshire sows vs. Hampshire-Duroc boars crossed with Landrace-Yorkshire sows, including carriers and non-carriers of the halothane and RN(-) genes, respectively) were included. Early pm muscle temperature and the accompanying pH decline had a significant influence on the pork colour independent of genotype. The combination of high temperature and low pH early pm increased lightness and yellowness, which is ascribed to inactivation of oxygen-consuming enzymes and protein denaturation. The effect of early pm temperature and pH on pork redness was more complex. It appears to be closely related to the extent of heat generation, CP and ATP levels and pH immediately pm in the muscle, which influence the activity of oxygen-consuming enzymes. PMID:22061871

Lindahl, Gunilla; Henckel, Poul; Karlsson, Anders H; Andersen, Henrik J

2006-04-01

68

The colour wheels of art, perception, science and physiology  

NASA Astrophysics Data System (ADS)

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.

Harkness, Nick

2006-06-01

69

Frugal Colouring of Graphs  

Microsoft Academic Search

A k-frugal colouring of a graph G is a proper colouring of the vertices of G such that no colour appears more than k times in the neighbourhood of a vertex. This type of colouring was introduced by Hind, Molloy and Reed in 1997. In this paper, we study the frugal chromatic number of planar graphs, planar graphs with large

Omid Amini; Louis Esperet; Jan Van Den Heuvel

2007-01-01

70

The Active Human Gut Microbiota Differs from the Total Microbiota  

PubMed Central

The human gut microbiota is considered one of the most fascinating reservoirs of microbial diversity hosting between 400 to 1000 bacterial species distributed among nine phyla with Firmicutes, Bacteroidetes and Actinobacteria representing around of the diversity. One of the most intriguing issues relates to understanding which microbial groups are active players in the maintenance of the microbiota homeostasis. Here, we describe the diversity of active microbial fractions compared with the whole community from raw human fecal samples. We studied four healthy volunteers by 16S rDNA gene pyrosequencing. The fractions were obtained by cell sorting based on bacterial RNA concentration. Bacterial families were observed to appear or disappear on applying a cell sorting method in which flow cytometry was used to evaluate the active cells by pyronin-Y staining of RNA. This method was able to detect active bacteria, indicating that the active players differed from that observed in raw fecal material. Generally, observations showed that in the active fractions, the number of reads related to Bacteroidetes decreased whereas several families from Clostridiales (Firmicutes) were more highly represented. Moreover, a huge number of families appeared as part of the active fraction when cell sorting was applied, indicating reads that are simply statistically hidden by the total reads. PMID:21829462

Peris-Bondia, Francesc; Latorre, Amparo; Artacho, Alejandro; Moya, Andres; D'Auria, Giuseppe

2011-01-01

71

Patterns of serum carotenoid accumulation and skin colour variation in kestrel nestlings in relation to breeding conditions and different terms of carotenoid supplementation.  

PubMed

Carotenoids are pigments synthesised by autotrophic organisms. For nestlings of raptorial species, which obtain carotenoids from the consumption of other heterotrophic species, the access to these pigments can be crucial. Carotenoids, indeed, have fundamental health maintenance functions, especially important in developing individuals as nestling kestrels. The aim of this study was to investigate how body carotenoid levels and skin pigmentation vary in kestrel nestlings (Falco tinnunculus) in relation to nesting parameters. Furthermore, we experimentally altered carotenoid availability (short- medium- and long-term) for nestlings and investigated skin and serum variance. The skin colour variance of 151 nestlings was explained by nest of origin, age and by the body condition (body mass corrected by age), older nestlings with higher body condition being redder. No difference in skin colour was detected between sexes. Differences in hue (skin "redness") between treatments did not emerge during the first week, but did occur 15 days after administration between long-term supplemented and control chicks. In contrast, the serum carotenoid concentration showed a treatment-dependent increase after 5 days from the first carotenoid administration and at least after two supplemented feedings. In general, hue but not serum carotenoids, was correlated with the body condition of nestlings. Based on the increased skin pigmentation of nestling kestrels in the long-term experimental group, we suggest carotenoid availability to be limited for colour expression. The small increase of serum carotenoids due to supplementation is consistent with the hypothesis that there is a physiological constraint on these pigments, as well as an environmental limitation. The presented results are useful for the understanding of carotenoid uptake and accumulation by a wild raptorial species, located at the top of the food web, highlighting that carotenoids are a limited resource for kestrel nestlings. PMID:17091273

Casagrande, Stefania; Costantini, David; Fanfani, Alberto; Tagliavini, James; Dell'Omo, Giacomo

2007-02-01

72

Colour in insect thermoregulation: empirical and theoretical tests in the colour-changing grasshopper, Kosciuscola tristis.  

PubMed

Body colours can result in different internal body temperatures, but evidence for the biological significance of colour-induced temperature differences is inconsistent. We investigated the relationship between body colour and temperature in a model insect species that rapidly changes colour. We used an empirical approach and constructed a heat budget model to quantify whether a colour change from black to turquoise has a role in thermoregulation for the chameleon grasshopper (Kosciuscola tristis). Our study shows that colour change in K. tristis provides relatively small temperature differences that vary greatly with wind speed (0.55 °C at ms(-1) to 0.05 °C at 10 ms(-1)). The biological significance of this difference is unclear and we discuss the requirement for more studies that directly test hypotheses regarding the fitness effects of colour in manipulating body temperature. PMID:23108152

Umbers, K D L; Herberstein, M E; Madin, J S

2013-01-01

73

Feeding efficiency of planktivores under disturbance, the effect of water colour, predation threat and shoal composition.  

PubMed

The consumption of phantom midge Chaoborus flavicans larvae by Perca fluviatilis showed clear response to water colour, predation threat and shoal composition with the most significant negative effect for water colour. In the case of Rutilus rutilus, no similar combined response was observed and the total prey consumption was significantly negatively affected by predation threat of Esox lucius. The results suggest that differences in life-history traits may result in disparity in species-specific responses to disturbance. PMID:24689675

Nurminen, L; Estlander, S; Olin, M; Lehtonen, H

2014-04-01

74

"Close" Encounters...of a Totally Different Kind.  

ERIC Educational Resources Information Center

Presents a project used in an advanced art class in which students focus on the work of Chuck Close by creating large self-portraits in the manner of Close. Describes the work of different students, such as how one student made a portrait using different colors of Skittles candy. (CMK)

Greenman, Geri

2001-01-01

75

Colourful Simplicial Depth  

Microsoft Academic Search

Inspired by Barany's Colourful Caratheodory Theorem (4), we introduce a colourful generalization of Liu's simplicial depth (13). We prove a parity property and con- jecture that the minimum colourful simplicial depth of any core point in any d-dimensional configuration is d 2 + 1 and that the maximum is d d+1 + 1. We exhibit configurations attain- ing each of

Antoine Deza; Sui Huang; Tamon Stephen; Tamás Terlaky

2006-01-01

76

Does Colour Preference Have a Role in Colour Term Acquisition?  

ERIC Educational Resources Information Center

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…

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

2009-01-01

77

Effects of soaking, boiling and autoclaving on the phenolic contents and antioxidant activities of faba beans (Vicia faba L.) differing in seed coat colours.  

PubMed

The Australian grown faba beans of different seed coat colours were either soaked, boiled or autoclaved, and analysed for phenolic contents and antioxidant activity using an array of reagent-based assays. Soaking, boiling and autoclaving were shown to lower the level of active compounds in faba beans. A significant amount of active compounds was leached to the soaking and cooking medium. Boiling was a better method in retaining active compounds in beans than autoclaving. The boiled beans had more active compounds than those of resulting cooking broths, which was the opposite observation when autoclaving. The buff-genotypes had a similar level of active compounds to red- and green-genotypes. The high performance liquid chromatography-post column derivatisation (HPLC-PCD) system detected a dense collection of high antioxidant HPLC peaks ('humps') in extracts of raw, soaked and boiled beans. The present findings encouraged consumption of faba beans together with cooking broth for the maximum potential health benefits. PMID:24001866

Siah, Siem; Wood, Jennifer A; Agboola, Samson; Konczak, Izabela; Blanchard, Christopher L

2014-01-01

78

Hemispherical total emissivity of Hastelloy N with different surface conditions  

NASA Astrophysics Data System (ADS)

The hemispherical total emissivity of Hastelloy N (a candidate structural material for Next Generation Nuclear Plants (NGNPs), particularly for the molten fluoride cooled reactors) was measured using an experimental set-up that was constructed in accordance with the standard ASTM C835-06. The material surface conditions included: (i) 'as received' (original) sample from the supplier; (ii) samples with increased surface roughness through sand blasting; (iii) oxidized surface, and (iv) samples coated with graphite powder. The emissivity of the as received samples varied from around 0.22 to 0.28 in the temperature range of 473 K to 1498 K. The emissivity increased when the roughness of the surface increased compared to an as received sample. When Hastelloy N was oxidized in air at 1153 K or coated with graphite powder, its emissivity increased substantially. The sample sand blasted with 60 grit beads and sprinkled with graphite powder showed an increase of emissivity from 0.2 to 0.60 at 473 K and from 0.25 to 0.67 at 1473 K. The oxidized surface showed a similar behavior: an increase in emissivity compared to an unoxidized sample. This increase in emissivity has strong favorable safety implications in terms of decay heat removal in post-accident environments. The data were compared with another Hastelloy family member, Hastelloy X.

Gordon, Andrew J.; Walton, Kyle L.; Ghosh, Tushar K.; Loyalka, Sudarshan K.; Viswanath, Dabir S.; Tompson, Robert V.

2012-07-01

79

Differences in Colour Gamut Obtained with Three Synthetic Red Food Colorants Compared with Three Natural Ones. pH and Heat Stability  

Microsoft Academic Search

The current trend in European markets towards natural ingredients has stimulated the interest in natural colorants. When it is decided to replace a colorant, normally a synthetic colorant with a natural one, it is interesting to know how the colour would be perceived, by locating their coordinates in the a*b*-diagram. The colours of three red natural colorants and three red

A. Arocas; P. Varela; A. Salvador; F. J. Heredia; S. M. Fiszman

2012-01-01

80

Colours experienced in dreams.  

PubMed

Colours seen in dreams by six observers were recorded from memory and plotted on a CIE u, v, chromaticity diagram. Only about half the dreams recorded contained colour, and in those in which colour appeared the more saturated purples, blues and blue greens were absent. It is suggested that during achromatic dreams the areas of the visual cortex which seem to respond only to colour may be inoperative. The paucity of blue in dreams could be anatomically related to the small population of blue units in the colour areas of the cortex. PMID:165850

Padgham, C A

1975-02-01

81

Practical colour management  

NASA Astrophysics Data System (ADS)

Spectrophotometers have been successfully used for colour measurement. This paper addresses digital imaging as a complementary and alternative method of colour measurement and appearance and an effective communication tool as part of a practical colour management programme within the supply chain of a textile retailer. The specific needs—to measure and communicate textured dyed material and printed fabric—are discussed, as well as the colour specification and quality control (QC) of currently un-measurable fabrics and accessories. A unique method of using digital imaging for the assessment of colour fastness will also be discussed.

Williams, Susan

2006-06-01

82

Colour Measurements and Modeling  

NASA Astrophysics Data System (ADS)

The most common property to measure quality of any material is its appearance. Appearance includes colour, shape, size and surface conditions. The analysis of colour is especially an important consideration when determining the efficacy of variety of postharvest treatments. Consumers can easily be influenced by preconceived ideas of how a particular fruit or vegetable or a processed food should appear, and marketers often attempt to improve upon what nature has painted. Recently colour measurements have also been used as quality parameters and indicator of some inner constituents of the material. In spite of the significance of colour in food industries, many continue to analyze it inadequately. This chapter deals with theory of colour, colour scales and its measurement, sampling techniques, and modeling of colour values for correlating them with some internal quality parameters of selected fruits.

Jha, Shyam N.

83

Total Factor Productivity, Human Capital, and Outward Orientation: Differences by Stage of Development and Geographic Regions  

E-print Network

Total Factor Productivity, Human Capital, and Outward Orientation: Differences by Stage. Then we estimate the total factor productivity series for each classification. Using determinants of total factor productivity that include, among many others, human capital, openness, and distortion of domestic

Ahmad, Sajjad

84

Colour Mathematics: With Graphs and Numbers  

ERIC Educational Resources Information Center

The different combinations involved in additive and subtractive colour mixing can often be difficult for students to remember. Using transmission graphs for filters of the primary colours and a numerical scheme to write out the relationships are good exercises in analytical thinking that can help students recall the combinations rather than just…

LoPresto, Michael C.

2009-01-01

85

An incomplete Kochen-Specker colouring  

Microsoft Academic Search

A particular incomplete Kochen-Specker colouring, suggested by Appleby in dimension three, is generalized to arbitrary dimension. We investigate its effectivity as a function of dimension, using two different measures. A limit is derived for the fraction of the sphere that can be coloured using the generalized Appleby construction as the number of dimensions approaches infinity. The second, and physically more

Helena Granstrom

86

Colour polymorphism in birds: causes and functions  

Microsoft Academic Search

We studied polymorphism in all species of birds that are presently known to show intraspecific variation in plumage colour. At least three main mecha- nisms have been put forward to explain the maintenance of polymorphism: apostatic, disruptive and sexual selection. All of them make partly different predictions. Our aims were to investigate evolutionary causes and adaptive functions of colour polymorphism

P. Galeotti; D. Rubolini; P. O. Dunn; M. Fasola

2003-01-01

87

Across light: through colour  

NASA Astrophysics Data System (ADS)

The speed at which our world is changing is reflected in the shifting way artistic images are created and produced. Holography can be used as a medium to express the perception of space with light and colour and to make the material and the immaterial experiments with optical and digital holography. This paper intends to be a reflection on the final product of that process surrounding a debate of ideas for new experimental methodologies applied to holographic images. Holography is a time-based medium and the irretrievable linear flow of time is responsible for a drama, unique to traditional cinematography. If the viewers move to left or right, they see glimpses of the next scene or the previous one perceived a second ago. This interaction of synthetic space arises questions such as: can we see, in "reality", two forms in the same space? Trying to answer this question, a series of works has been created. These concepts are embryonic to a series of digital art holograms and lenticulars technique's titled "Across Light: Through Colour". They required some technical research and comparison between effects from different camera types, using Canon IS3 and Sony HDR CX105.

Azevedo, Isabel; Richardson, Martin; Bernardo, Luis Miguel

2012-03-01

88

Galaxy Zoo: the dependence of morphology and colour on environment  

NASA Astrophysics Data System (ADS)

We analyse the relationships between galaxy morphology, colour, environment and stellar mass using data for over 105 objects from Galaxy Zoo, the largest sample of visually classified morphologies yet compiled. We conclusively show that colour and morphology fractions are very different functions of environment. Both colour and morphology are sensitive to stellar mass. However, at fixed stellar mass, while colour is also highly sensitive to environment, morphology displays much weaker environmental trends. Only a small part of both the morphology-density and colour-density relations can be attributed to the variation in the stellar-mass function with environment. Galaxies with high stellar masses are mostly red in all environments and irrespective of their morphology. Low stellar-mass galaxies are mostly blue in low-density environments, but mostly red in high-density environments, again irrespective of their morphology. While galaxies with early-type morphology do always have higher red fractions, this is subdominant compared to the dependence of red fraction on stellar mass and environment. The colour-density relation is primarily driven by variations in colour fractions at fixed morphology, in particular the fraction of spiral galaxies that have red colours, and especially at low stellar masses. We demonstrate that our red spirals primarily include galaxies with true spiral morphology, and that they constitute an additional population to the S0 galaxies considered by previous studies. We clearly show there is an environmental dependence for colour beyond that for morphology. The environmental transformation of galaxies from blue to red must occur on significantly shorter time-scales than the transformation from spiral to early-type. We also present many of our results as functions of the distance to the nearest galaxy group. This confirms that the environmental trends we present are not specific to the manner in which environment is quantified, but nevertheless provides plain evidence for an environmental process at work in groups. However, the properties of group members show little dependence on the total mass of the group they inhabit, at least for group masses . Before using the Galaxy Zoo morphologies to produce the above results, we first quantify a luminosity-, size- and redshift-dependent classification bias that affects this data set, and probably most other studies of galaxy population morphology. A correction for this bias is derived and applied to produce a sample of galaxies with reliable morphological-type likelihoods, on which we base our analysis. This publication has been made possible by the participation of more than 100, 000 volunteers in the Galaxy Zoo project. Their contributions are acknowledged at http://www.galaxyzoo.org/Volunteers.aspx E-mail: steven.bamford@nottingham.ac.uk

Bamford, Steven P.; Nichol, Robert C.; Baldry, Ivan K.; Land, Kate; Lintott, Chris J.; Schawinski, Kevin; Slosar, Anže; Szalay, Alexander S.; Thomas, Daniel; Torki, Mehri; Andreescu, Dan; Edmondson, Edward M.; Miller, Christopher J.; Murray, Phil; Raddick, M. Jordan; Vandenberg, Jan

2009-03-01

89

Occupational colour vision requirements for police officers.  

PubMed

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. PMID:19076554

Birch, Jennifer; Chisholm, Catharine M

2008-11-01

90

The colour preference control based on two-colour combinations  

NASA Astrophysics Data System (ADS)

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.

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

2008-02-01

91

Shelflife and colour change kinetics of Aloe vera gel powder under accelerated storage in three different packaging materials  

Microsoft Academic Search

Aloe vera gel powder was produced through dehumidified air drying of Aloe vere gel at optimized conditions of temperature,\\u000a relative humidity and air velocity of 64 °C, 18% and 0.8 m.s?1, respectively. The powder was packed in three different packaging materials viz., laminated aluminum foil (AF), biaxially oriented polypropylene (BOPP) and polypropylene (PP). The shelf-life of the powder\\u000a was predicted on the

C. T. Ramachandra; P. Srinivasa Rao

92

Colour management is a socio-technical problem  

Microsoft Academic Search

This paper describes how achieving consistent colour reproduction across different devices is a complicated matter. Although there is a technological infrastructure for managing colour across devices this is very rarely used as intended. This infrastructure has been created by modelling the problem of colour management as a wholly technical one. In this paper we illustrate the importance of understanding the

Jacki O'neill; David Martin; Tommaso Colombino; Frédéric Roulland; Jutta Willamowski

2008-01-01

93

Dependence between colour and individual anthocyanin content in ripening grapes  

Microsoft Academic Search

Three red grape cultivars of different coloration (Flame seedless, Exotic and Monastrell), grown in Murcia (southeast Spain) were analysed during ripening for external colour and individual pigment content. The application of the CIRG colour index, calculated from the coordinates hue angle (h), lightness (L*) and chroma (C*) of the CIELAB colour space, and defined as [(180-h)\\/(L*+C*)], permitted an objective evaluation

José A Fernández-López; Luis Almela; José A Muñoz; Venancio Hidalgo; Juan Carreño

1998-01-01

94

Colour, myoglobin denaturation and storage stability of raw and cooked mutton chops at different end point cooking temperature.  

PubMed

In our study effect of different end point temperature (51 °C, 65 °C, 71 °C and 79 °C) on physicochemical and storage stability of mutton chops were evaluated. The L* (lightness) value and b* (yellowness) increased (P?

Sen, A R; Naveena, B M; Muthukumar, M; Vaithiyanathan, S

2014-05-01

95

Colouring planar graphs  

Microsoft Academic Search

There is no known polynomial time 4-colouring algorithm for planar graphs, except the algorithms that can be derived from\\u000a the proofs of Appel et al. and Robertson et al. An alternative way to colour planar graphs is to investigate the problem of finding nowhere-zero k-flows in graphs.

Paulette Lieby

96

Object knowledge modulates colour appearance  

PubMed Central

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

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

2011-01-01

97

INVESTIGATION OF RESPONSE DIFFERENCES BETWEEN DIFFERENT TYPES OF TOTAL ORGANIC CARBON (TOC) ANALYTICAL INSTRUMENT SYSTEMS  

EPA Science Inventory

Total organic carbon (TOC) and dissolved organic carbon (DOC) have long been used to estimate the amount of natural organic matter (NOM) found in raw and finished drinking water. In recent years, computer automation and improved instrumental analysis technologies have created a ...

98

Total Phenolic Content and Antimicrobial Activity of Different Lithuanian Propolis Solutions  

PubMed Central

The manufacture of ethanol-free propolis solutions offers a broader application. A few trials with Lithuanian propolis have been conducted. The aims of the study are to manufacture propolis water and water-free solutions and evaluate the quality and antimicrobial activity of these solutions. The studied solutions containing 2.5%, 5%, and 10% propolis are prepared. As solvents, purified water, 70%?v/v ethanol, 96.3%?v/v ethanol, propylene glycol, and their systems were used. Determination of total levels of phenolic compounds (FAE?mg/g) is based on colour oxidation-reduction reaction using Folin-Ciocalteu reagent under alkaline conditions and performed at 765?nm wavelength using UV spectrophotometer. The highest content of phenolic compounds was determined in solutions containing 10% propolis extracts, and the lowest amounts in 2.5% propolis extracts. The water extracted the lowest amount of phenolic compounds from crude propolis, ethanol extracted the highest amount, and propylene glycol ranked the middle position. It is determined that technological parameters (stirring, temperature) contribute to content of phenolic compounds. During microbiological study, MICs were determined. The studies showed that water extracted propolis solutions and solvents mixture did not inhibit the growth of the studied microorganisms, and propolis solutions in propylene glycol were found to have antimicrobial activity. PMID:23573156

Ramanauskiene, Kristina; Inkeniene, Asta Marija; Petrikaite, Vilma; Briedis, Vitalis

2013-01-01

99

Seasonal Changes in Colour: A Comparison of Structural, Melanin- and Carotenoid-Based Plumage Colours  

PubMed Central

Background Plumage coloration is important for bird communication, most notably in sexual signalling. Colour is often considered a good quality indicator, and the expression of exaggerated colours may depend on individual condition during moult. After moult, plumage coloration has been deemed fixed due to the fact that feathers are dead structures. Still, many plumage colours change after moult, although whether this affects signalling has not been sufficiently assessed. Methodology/Principal Findings We studied changes in coloration after moult in four passerine birds (robin, Erithacus rubecula; blackbird, Turdus merula; blue tit, Cyanistes caeruleus; and great tit, Parus major) displaying various coloration types (melanin-, carotenoid-based and structural). Birds were caught regularly during three years to measure plumage reflectance. We used models of avian colour vision to derive two variables, one describing chromatic and the other achromatic variation over the year that can be compared in magnitude among different colour types. All studied plumage patches but one (yellow breast of the blue tit) showed significant chromatic changes over the year, although these were smaller than for a typical dynamic trait (bill colour). Overall, structural colours showed a reduction in relative reflectance at shorter wavelengths, carotenoid-based colours the opposite pattern, while no general pattern was found for melanin-based colours. Achromatic changes were also common, but there were no consistent patterns of change for the different types of colours. Conclusions/Significance Changes of plumage coloration independent of moult are probably widespread; they should be perceivable by birds and have the potential to affect colour signalling. PMID:20644723

Delhey, Kaspar; Burger, Claudia; Fiedler, Wolfgang; Peters, Anne

2010-01-01

100

The connotations of colour terms: colour based X-phemisms  

Microsoft Academic Search

This paper investigates the connotations of colour terms with particular attention to figurative uses of black, white, grey, brown, yellow, red, green, blue and a few miscellaneous colours. The connotations are judged on the basis of whether the phrases in which the colour terms occur are typically orthophemistic, euphemistic, or dysphemistic. All the colours surveyed have some, often many, orthophemistic

Keith Allan

101

HUMAN COLOUR VISION: 2. COLOUR APPEARANCE AND CORTICAL TRANSFORMATIONS  

E-print Network

HUMAN COLOUR VISION: 2. COLOUR APPEARANCE AND CORTICAL TRANSFORMATIONS JOHN S. WERNER Department in area V1 vary much more in their colour tuning than in LGN, and they have significantly more S is a "colour centre" in the monkey brain, and it is equally unlikely to be homologous with those regions

Olshausen, Bruno

102

On the presence of hydrous defects in differently coloured wulfenites (PbMoO4): an infrared and optical spectroscopic study  

NASA Astrophysics Data System (ADS)

Several samples of wulfenite, PbMoO4, varying in colour from colourless to yellow, orange and red, have been characterised by means of IR and optical absorption spectroscopy and by microprobe analyses. A distinct pleochroic band group with absorption maxima centred at 3,380 and 3,150 cm-1 can be seen in the IR spectra of wulfenite single-crystals, indicating the presence of hydroxyl groups. The pleochroic and thermal behaviour of the OH stretching bands along with deuteration experiments, as well as results obtained from synthetic flux-grown samples, exclude the presence of submicroscopic hydrous mineral inclusions as their primary origin. The pleochroic scheme and the band positions were used to postulate a model for the OH incorporation mode, based on the assumption of vacancies on Mo and Pb sites in the structure of this ‘nominally anhydrous mineral’. Optical absorption spectra of coloured natural samples show a broad and polarised band around 23,000-24,000 cm-1, preceding the fundamental UV absorption edge, which has been identified as the reason for the colour of the mineral. The comparison with synthetic PbMoO4 single-crystals, doped with variable amounts of Cr6+, yielded conclusive evidence that trace amounts of the CrO4 2- anion group, substituting for MoO4 2-, determine the variable colour. Besides, in one sample, trace amounts of Nd3+ have been spectroscopically identified.

Talla, D.; Wildner, M.; Beran, A.; Škoda, R.; Losos, Z.

2013-11-01

103

Biological components of colour preference in infancy.  

PubMed

Adult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S-(L+M) ('blue-yellow') and L-M ('red-green') cone-opponent contrast channels (Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in 4-5-month-olds may be analysed in the same way. We recorded infants' eye-movements in response to pairwise presentations of eight colour stimuli varying only in hue. Infants looked longest at reddish and shortest at greenish hues. Analyses revealed that the L-M and S-(L+M) contrast between stimulus colour and background explained around half of the variation in infant preference across the hue spectrum. Unlike adult colour preference patterns, there was no evidence for sex differences in the weights on either of the cone-opponent contrast components. The findings provide a quantitative model of infant colour preference that summarizes variation in infant preference across hues. PMID:20136931

Franklin, Anna; Bevis, Laura; Ling, Yazhu; Hurlbert, Anya

2010-03-01

104

Colour and lighting in hospital design  

NASA Astrophysics Data System (ADS)

Little information or guidance has been available to assist the development of a hospital's visual environment. A report on lighting and colour design schemes, accessible to non professionals with responsibility for refurbishment strategies, was required by NHS Estates. Firstly, 20 hospitals were audited to establish a picture of current practice and to identify key issues where colour design could broadly enhance the environment for patients, staff and visitors. Critical areas were outlined in this report, where colour design can be utilised and applied, for the benefit of all users, from ambience to essential legal requirements such as colour contrast for the visually impaired. Provision of staff relaxation rooms that are different in terms of colour and lux levels from immediate work spaces, or thoughtfully designed areas for patients awaiting intensive treatment, have been shown to have some beneficial effects on a sense of well being. Colour and design have not been established as a definite cure for sickness and ill health, but certainly monotony and poor conditions in premises that have not been refurbished with any care, have had a detrimental affect on recovery rates and staff morale. The realisation that a well balanced and attractive environment is of major importance to patients' health is, in no way new; Florence Nightingale observed that 'a variety of form and brilliance of colour in the objects presented to patients are an actual means of recovery'.

Dalke, Hilary; Little, Jenny; Niemann, Elga; Camgoz, Nilgun; Steadman, Guillaume; Hill, Sarah; Stott, Laura

2006-06-01

105

ORIGINAL PAPER What weta want: colour preferences of a frugivorous insect  

E-print Network

animal mutualists, plants often use colour signals. Fruits and flowers are often brightly coloured+Business Media B.V. 2010 Abstract Plants use colours as signals to attract mutual- ists and repel antagonists on their pigmentation and whether different lighting conditions affect fruit colour selection. We captured 20 Wellington

106

Categorical Effects in Children's Colour Search: A Cross-Linguistic Comparison  

ERIC Educational Resources Information Center

In adults, visual search for a colour target is facilitated if the target and distractors fall in different colour categories (e.g. Daoutis, Pilling, & Davies, in press). The present study explored category effects in children's colour search. The relationship between linguistic colour categories and perceptual categories was addressed by…

Daoutis, Christine A.; Franklin, Anna; Riddett, Amy; Clifford, Alexandra; Davies, Ian R. L.

2006-01-01

107

Floral colour diversity in plant communities, bee colour space and a null model  

PubMed Central

Evolutionary biologists have long hypothesized that the diversity of flower colours we see is in part a strategy to promote memorization by pollinators, pollinator constancy, and therefore, a directed and efficient pollen transfer between plants. However, this hypothesis has never been tested against a biologically realistic null model, nor were colours assessed in the way pollinators see them. Our intent here is to fill these gaps. Throughout one year, we sampled floral species compositions at five ecologically distinct sites near Berlin, Germany. Bee-subjective colours were quantified for all 168 species. A model of colour vision was used to predict how similar the colours of sympatric and simultaneously blooming flowers were for bees. We then compared flower colour differences in the real habitats with those of random plant communities. We did not find pronounced deviations from chance when we considered common plants. When we examined rare plants, however, we found significant divergence in two of the five plant communities. At one site, similarly coloured species were found to be more frequent than expected, and at the other two locations, flower colours were indistinguishable from a random distribution. These results fit theoretical considerations that rare plants are under stronger selective pressure to secure pollination than common plants. Our study illustrates the power of linking such distinct biological traditions as community ecology and the neuroethology of bee vision.

Gumbert, A.; Kunze, J.; Chittka, L.

1999-01-01

108

Rockpool gobies change colour for camouflage.  

PubMed

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

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

2014-01-01

109

Rockpool Gobies Change Colour for Camouflage  

PubMed Central

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

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

2014-01-01

110

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

PubMed

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. PMID:23458658

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

2013-04-30

111

Colourful parrot feathers resist bacterial degradation  

PubMed Central

The brilliant red, orange and yellow colours of parrot feathers are the product of psittacofulvins, which are synthetic pigments known only from parrots. Recent evidence suggests that some pigments in bird feathers function not just as colour generators, but also preserve plumage integrity by increasing the resistance of feather keratin to bacterial degradation. We exposed a variety of colourful parrot feathers to feather-degrading Bacillus licheniformis and found that feathers with red psittacofulvins degraded at about the same rate as those with melanin and more slowly than white feathers, which lack pigments. Blue feathers, in which colour is based on the microstructural arrangement of keratin, air and melanin granules, and green feathers, which combine structural blue with yellow psittacofulvins, degraded at a rate similar to that of red and black feathers. These differences in resistance to bacterial degradation of differently coloured feathers suggest that colour patterns within the Psittaciformes may have evolved to resist bacterial degradation, in addition to their role in communication and camouflage. PMID:20926430

Burtt, Edward H.; Schroeder, Max R.; Smith, Lauren A.; Sroka, Jenna E.; McGraw, Kevin J.

2011-01-01

112

Pre-bottling use of dehydrated waste grape skins to improve colour, phenolic and aroma composition of red wines.  

PubMed

Different dehydrated waste grape skins from the juice industry were added into aged and young red wines as an innovative way of compensating for colour loss before bottling. After addition of grape skins, colour intensity of wines increased a mean 11% and a maximum of 31% with predominance of the red component. Total polyphenols mean increase was 10% with a maximum value of 20%. Analysis of low molecular weight phenolic compounds by HPLC-DAD showed a significant (p<0.05) content increase of the bioactive compounds gallic acid, (+)-catechin, (-)-epicatechin, and (E)-resveratrol. Anthocyanins content also increased at an average of 50mg/l. The volatile profile of wines analysed by SBSE-GC-MS was only moderately influenced by the treatments. Mixtures of dehydrated waste grape skins were useful to improve the colour and polyphenol profile of red wines, considering them a useful tool for correcting colour loss before bottling. PMID:23017417

Pedroza, Miguel Angel; Carmona, Manuel; Alonso, Gonzalo Luis; Salinas, Maria Rosario; Zalacain, Amaya

2013-01-01

113

Colour Stability of Veneering Composites after Accelerated Aging  

PubMed Central

Objectives: To investigate the colour stability of four indirect composite restorative materials after accelerated aging. Methods: Four indirect composites (Gradia, Signum+, HFO and Adoro) were used. For each material, six specimens were prepared and subjected to accelerated aging (Suntest CPS+, Atlas, Chicago, IL, USA) according to ISO 7491. A Dr. Lange Microcolor Data Station colorimeter (Braive Instruments, Liege, Belgium) was used to measure specimen colour before and after aging. Measurements were performed according to the CIE L*a*b* system, and the mean L*, a* and b* values for each material were calculated. The equation ?E = [(?L*)2 + (?a*)2 + (?b*)2]1/2 was used to measure the total colour change (?E), where ?L*, ?a* and ?b* are the differences in the respective values before and after aging. One-way ANOVA were used to determine statistically significant differences in ?L*, ?a*, ?b* and ?E. Results: No statistically significant differences were found in ?L*, ?a*, ?b* and ?E among the materials tested (P?L*=.063; P?a*=.521; P?b*=.984 and P?E=.408). After aging, Gradia specimens showed an increase in lightness (?L*=0.36) and a green-yellow shift (?a*=?1.18, ?b*=0.6), while Signum+ specimens exhibited an increase in lightness (?L*=0.5) and a green-blue shift (?a*=?0.9, ?b*=?0.45). HFO specimens exhibited an increase in lightness (?L*=0.75) and a green-yellow shift (?a*=?1.3, ?b*=0.06), and Adoro specimens exhibited an increase in lightness (?L*=2.07) and a green-yellow shift (?a*=?1.3, ?b*=0.68). Conclusions: Colour changes were found to be within accepted values of perceptibility and clinical acceptance after accelerated aging, and no statistically significant differences were found in ?L*, ?a*, ?b* and ?E among the materials tested. PMID:20396443

Papadopoulos, Triantafillos; Sarafianou, Aspasia; Hatzikyriakos, Andreas

2010-01-01

114

Colour in flux: describing and printing colour in art  

NASA Astrophysics Data System (ADS)

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.

Parraman, Carinna

2008-01-01

115

Flower colour adaptation in a mimetic orchid  

PubMed Central

Although the tremendous variability in floral colour among angiosperms is often attributed to divergent selection by pollinators, it is usually difficult to preclude the possibility that floral colour shifts were driven by non-pollinator processes. Here, we examine the adaptive significance of flower colour in Disa ferruginea, a non-rewarding orchid that is thought to attract its butterfly pollinator by mimicking the flowers of sympatric nectar-producing species. Disa ferruginea has red flowers in the western part of its range and orange flowers in the eastern part—a colour shift that we hypothesized to be the outcome of selection for resemblance to different local nectar-producing plants. Using reciprocal translocations of red and orange phenotypes as well as arrays of artificial flowers, we found that the butterfly Aeropetes tulbaghia, the only pollinator of the orchid, preferred both the red phenotype and red artificial flowers in the west where its main nectar plant also has red flowers, and both the orange phenotype and orange artificial flowers in the east, where its main nectar plant has orange flowers. This phenotype by environment interaction demonstrates that the flower colour shift in D. ferruginea is adaptive and driven by local colour preference in its pollinator. PMID:22298842

Newman, Ethan; Anderson, Bruce; Johnson, Steven D.

2012-01-01

116

Flesh colour dominates consumer preference for chicken.  

PubMed

Existing research investigating interactions between visual and oral sensory cues has tended to use model food systems. In contrast, this study compared product quality assessments of corn-fed and wheat-fed chicken products among persons recruited in Northern Ireland. Three approaches have been adopted to investigate the effect of colour upon consumer choice of chicken: sensory assessment under normal lighting; focus group discussion; and sensory assessment under controlled lighting conditions. Initial consumer sensory assessment indicated that wheat-fed chicken was perceived to be tenderer and to have a more intense flavour than that which was corn-fed. Qualitative enquiry discerned that this was because consumers perceived the yellow colour of corn-fed chicken negatively. Yellow-coloured corn-fed chicken was therefore again compared with wheat-fed chicken in terms of flavour, texture and overall liking with the flesh colour disguised by means of controlled lighting. Quality ratings for corn-fed chicken were more positive when the yellow flesh colour was disguised, with corn-fed chicken judged to be tenderer than wheat-fed chicken and more flavoursome. This study illustrates the importance of using a combination of methods to gain insight into interactions between different sensory modalities in consumer quality judgements and adds to previous research on the importance of colour upon consumer choice of real foods. PMID:15808892

Kennedy, Orla B; Stewart-Knox, Barbara J; Mitchell, Peter C; Thurnham, David I

2005-04-01

117

Colouring as a special list-colouring problem  

Microsoft Academic Search

Colouring of planar graphs can be treated as a special list-colouring problem\\u000awith selected lists for near-triangulations. The new idea is to use sublists of\\u000aa common list of four colours, to enforce a common colour in all lists, and to\\u000aadmit on the bounding cycle at most one vertex with a list of at least two\\u000acolours. By these

Peter Doerre

2004-01-01

118

A study to assess the colour stability of acetal resins subjected to thermocycling.  

PubMed

The purpose of this study was to compare colour stability of pink and white acetal resin with one conventional poly (methylmethacrylate) resin. Five specimen disks 50 +/- 0.1 mm in diameter and approximately 1.0 mm thick were prepared from each material. The discs were hydrated for a period of 30 days in distilled water and were then desiccated to a constant weight. Total of fifteen specimens were thermocycled for 100 and 300 hours (4000-12000 cycle) between water baths of 5-55 degrees C. Changes from baseline colour readings were recorded at each interval. Data were analysed with descriptive statistic, repeated measured analysis of variance and single factor analysis of variance. The colour changes for all materials at 100 hours were in the categories of slight, based upon the National Bureau of Standard System (NBS) for expressing colour difference. At 300 hours, the colour changes of materials were significantly different (p = 0.0001). All the materials tested showed clinically acceptable discolouration values. PMID:15819144

Ozkan, Y; Arikan, A; Akalin, B; Arda, T

2005-03-01

119

Analyzing total knee arthroplasty using surgical volume of different hospital levels  

Microsoft Academic Search

The purpose of this research is to discover valuable medical facts by mining TKA (total knee arthroplasty) surgical volume of three different hospital levels from Taiwan NHI (National Health Insurance) database. In this paper, there are three main objectives provided: (1) to build up the learning curves using the patients¿ outcomes of three different hospital levels; (2) to characterize whether

Y. T. Cheng; C. H. Cheng; J. S. Chen

2008-01-01

120

Ultrasonic colour Doppler imaging  

PubMed Central

Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been found to be of great value in assessing blood flow in many clinical conditions. Although the method for obtaining the velocity information is in many ways similar to the method for obtaining the anatomical information, it is technically more demanding for a number of reasons. It also has a number of weaknesses, perhaps the greatest being that in conventional systems, the velocities measured and thus displayed are the components of the flow velocity directly towards or away from the transducer, while ideally the method would give information about the magnitude and direction of the three-dimensional flow vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new techniques that seek to overcome the vector problem mentioned above are described. Finally, some examples of vector velocity images are presented. PMID:22866227

Evans, David H.; Jensen, J?rgen Arendt; Nielsen, Michael Bachmann

2011-01-01

121

Use of Descartes Folium Equation for Deriving a Relation between Total Aperture of Fractures after Uniaxial Compression and Strain Parameters of Different Rocks Exhibiting Negative Total Volumetric Strains  

NASA Astrophysics Data System (ADS)

The axial, crack and total volumetric strains, porosity, elastic constants, crack damage stresses, uniaxial compressive strengths, as well as fracture apertures and number of fracture traces in rock samples surface after compression were defined for different chalk, basalt, dolomite, granite, limestone and sandstone samples exhibiting negative total volumetric strain at failure. It is established that the total (summed) aperture of vertical fractures obtained on the lateral surface of rock sample is related to three characteristic strain parameters: axial strain at the onset of negative total volumetric strain, axial failure strain and negative total volumetric strain at failure. The relation is based on Descartes folium equation, where the length of the loop of folium is equal to axial strain coordinate at the onset of negative total volumetric strain. This relation shows that the total aperture increases according to power law with increasing difference between axial failure strain and axial strain at the onset of negative total volumetric strain. Simultaneously, an increase in this difference leads to an increase in the value of negative total volumetric strain at failure. It is found that a direct correlation between total aperture of fractures and negative total volumetric strain at failure is relatively weak. Nevertheless, total aperture of fractures tends to increase with increasing absolute value of negative total volumetric strain at failure. It is revealed that there is no connection between the number of fracture traces and negative total volumetric strain at failure.

Palchik, V.

2014-11-01

122

Adult total wellness: group differences based on sitting time and physical activity level  

PubMed Central

Background An increasing body of evidence associates a high level of sitting time with poor health outcomes. The benefits of moderate to vigorous-intensity physical activities to various aspects of health are now well documented; however, individuals may engage in moderate-intensity physical activity for at least 30 minutes on five or more days of the week and still exhibit a high level of sitting time. This purpose of this study was to examine differences in total wellness among adults relative to high/low levels of sitting time combined with insufficient/sufficient physical activity (PA). The construct of total wellness incorporates a holistic approach to the body, mind and spirit components of life, an approach which may be more encompassing than some definitions of health. Methods Data were obtained from 226 adult respondents (27?±?6 years), including 116 (51%) males and 110 (49%) females. Total PA and total sitting time were assessed with the International Physical Activity Questionnaire (IPAQ) (short-version). The Wellness Evaluation of Lifestyle Inventory was used to assess total wellness. An analysis of covariance (ANCOVA) was utilised to assess the effects of the sitting time/physical activity group on total wellness. A covariate was included to partial out the effects of age, sex and work status (student or employed). Cross-tabulations were used to show associations between the IPAQ derived high/low levels of sitting time with insufficient/sufficient PA and the three total wellness groups (i.e. high level of wellness, moderate wellness and wellness development needed). Results The majority of the participants were located in the high total sitting time and sufficient PA group. There were statistical differences among the IPAQ groups for total wellness [F (2,220) = 32.5 (p <0.001)]. A Chi-square test revealed a significant difference in the distribution of the IPAQ categories within the classification of wellness [?2 (N = 226) = 54.5, p?total sitting time/insufficient PA were found in the wellness development needed group. In contrast, 72% of participants who were located in the low total sitting time/sufficient PA group were situated in the moderate wellness group. Conclusion Many participants who meet the physical activity guidelines, in this sample, sit for longer periods of time than the median Australian sitting time. An understanding of the effects of the enhanced PA and reduced sitting time on total wellness can add to the development of public health initiatives. PMID:24602315

2014-01-01

123

Specifying colour and maintaining colour accuracy for 3D printing  

NASA Astrophysics Data System (ADS)

Advances in rapid prototyping technologies have led to the emergence of three-dimensional printers which can fabricate physical artefacts, including the application of surface colours. In light of these developments, this paper asserts that the need to print colour accurately is just as important for designers using three-dimensional colour printing as it is for two-dimensional inkjet printing. Parallels can be made with two-dimensional digital Inkjet printing and 2D common problems include: on screen previsualisation, colour management methods, colour gamut and maintaining colour accuracy. However, for three dimensional colour printed objects, there are more variables that will affect the finished colour. These are: the powder and process inks, unevenness of the surface, wax post-processing and other infiltration media and procedures. Furthermore, in some 3D printers, the K channel is replaced by the binder and so the printer is only using the cyan, magenta and yellow channels. The paper will suggest methods for improving pre-visualisation and accurate pre-viewing of the colours through the manufacture of three-dimensional colour charts as a reference guide for designers so that they can make accurate coloured artefacts. A series of case studies will be demonstrated.

Parraman, Carinna; Walters, Peter; Reid, Brendan; Huson, David

2008-02-01

124

Covariation between plumage colour polymorphism and diet in the Barn Owl Tyto alba  

Microsoft Academic Search

Several hypotheses might explain the evolution and maintenance of colour morphs within animal populations. The 'alternative foraging strategy' hypothesis states that alternative colour morphs exploit different ecological niches. This hypothesis predicts that morphs differ in diet, either because foraging success on alternative prey species is morph-dependent or because differently coloured individuals exploit alternative habitats. I examined this prediction in the

Alexandre Roulin

2004-01-01

125

COMMUNITY SCALE STREAM TAXA SENSITIVITIES TO DIFFERENT COMPOSITIONS OF EXCESS TOTAL DISSOLVED SOLIDS  

EPA Science Inventory

Model stream chronic dosing studies (42 d) were conducted with three total dissolved solids (TDS) recipes. The recipes differed in composition of major ions. Community scale emergence was compared with single-species responses conducted simultaneously using the whole effluent tox...

126

Relationship between joint gap difference and range of motion in total knee arthroplasty: a prospective randomised study between different platforms  

Microsoft Academic Search

The objective of this study was to investigate the range of motion (ROM) of the knee before and four years after total knee\\u000a arthroplasty (TKA) with a mobile or fixed type of platform and to prospectively evaluate whether there was a difference in\\u000a ligament balance between the platform types. The subjects were 68 patients involving 76 joints. The mobile type

Hiroshi Higuchi; Kazuhisa Hatayama; Masaki Shimizu; Atsushi Kobayashi; Tsutomu Kobayashi; Kenji Takagishi

2009-01-01

127

Relationship between colouration and body condition in a crab spider that lures pollinators.  

PubMed

Sit-and-wait predators have evolved several traits that increase the probability of encountering prey, including lures that attract prey. Although most crab spiders (Thomisidae) are known by their ability to change colour in order to match the background, a few use a different strategy. They are UV-reflective, creating a colour contrast against UV-absorbing flowers that is attractive for pollinators. The nature of the relationship between colour contrast and foraging success is unknown, as is how spiders trade off the potential costs and benefits of strong colour contrast. Therefore, this study investigated the relationship between spider colouration, foraging success and background colouration in a crab spider species known to lure pollinators via UV reflectance (Thomisus spectabilis). Field data revealed that spider body condition - a proxy of past foraging success - is positively related to overall colour contrast. We experimentally tested the effect of satiation and background colour on spider colour change. Throughout the experiment, spiders changed their colour contrast regardless of their food intake, suggesting that colour contrast and the UV component contributing to overall contrast are not caused by spider condition. Although spiders responded to different backgrounds by subtly changing their body colour, this did not result in colour matching. We believe that the observed variation in colour contrast and hence conspicuousness in the field, coupled with the spiders' reaction to our manipulation, could be the result of plasticity in response to prey. PMID:22399657

Gawryszewski, Felipe M; Llandres, Ana L; Herberstein, Marie E

2012-04-01

128

Development of a forensic skin colour predictive test.  

PubMed

There is growing interest in skin colour prediction in the forensic field. However, a lack of consensus approaches for recording skin colour phenotype plus the complicating factors of epistatic effects, environmental influences such as exposure to the sun and unidentified genetic variants, present difficulties for the development of a forensic skin colour predictive test centred on the most strongly associated SNPs. Previous studies have analysed skin colour variation in single unadmixed population groups, including South Asians (Stokowski et al., 2007, Am. J. Hum. Genet, 81: 1119-32) and Europeans (Jacobs et al., 2013, Hum Genet. 132: 147-58). Nevertheless, a major challenge lies in the analysis of skin colour in admixed individuals, where co-ancestry proportions do not necessarily dictate any one person's skin colour. Our study sought to analyse genetic differences between African, European and admixed African-European subjects where direct spectrometric measurements and photographs of skin colour were made in parallel. We identified strong associations to skin colour variation in the subjects studied from a pigmentation SNP discovery panel of 59 markers and developed a forensic online classifier based on naïve Bayes analysis of the SNP profiles made. A skin colour predictive test is described using the ten most strongly associated SNPs in 8 genes linked to skin pigmentation variation. PMID:25082135

Maroñas, Olalla; Phillips, Chris; Söchtig, Jens; Gomez-Tato, Antonio; Cruz, Raquel; Alvarez-Dios, José; de Cal, María Casares; Ruiz, Yarimar; Fondevila, Manuel; Carracedo, Angel; Lareu, María V

2014-11-01

129

Spatio-temporal colour correction of strongly degraded movies  

NASA Astrophysics Data System (ADS)

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

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

2011-01-01

130

Measuring the colour of rendering mortars  

NASA Astrophysics Data System (ADS)

When restoring decorative mortar layers on historic façades, professionals need to determine the colour of these finishes in order to select an appropriate repair mortar. Currently, the appearance of these renders is only assessed from a subjective point of view. To match with the aesthetic aspects of the façade, contractors must constantly adjust their repair mortar composition to avoid a patchwork of different colours, which is detrimental for heritage. This time-consuming (trial-and-error) methodology can be excluded by evaluating `colour' with an objective numerical approach. The challenge of the research was to define and evaluate optimal material dependent boundary conditions for measuring the colour of nonhomogeneous mortars. Four samples with different scale of heterogeneity were measured by two spectrocolorimeters, both with a diffuse illumination geometry. The results were plotted in CIE-L*a*b* colour space. By calculating the colour difference (?E*), the influence of measuring with or without specular component was evaluated. We discovered the minimal number of measuring points depends on the scale of heterogeneity and the aperture area. The less homogeneous the mortar sample is and the smaller the aperture area, the more unique measuring points are required. Therefore, it is recommended to choose an aperture head of 25 mm or more to reduce the number of measurements, making your work time-efficient. However, in order to obtain accurate measurements on site, a portable optical spectrum analyser can be used with a 6 mm-diameter aperture, a viewing angle of 10°, SCI mode, illumination source D65, considering a minimum of 15 unique measuring points.

Govaerts, Yves; Meulebroeck, Wendy; Verdonck, Ann; de Bouw, Michael

2014-05-01

131

Correlation between dichromatic colour vision and jumping performance in horses.  

PubMed

There is general agreement that horses have dichromatic colour vision with similar capabilities to human beings with red-green colour deficiencies. However, whether colour perception has an impact on equine jumping performance and how pronounced the colour stimulus might be for a horse is unknown. The present study investigated the relationship between the colour of the fences (blue or green) and the show jumping performance of 20 horses ridden by two riders using an indoor and outdoor set of green and blue fences. In the indoor arena, significantly more touches and faults were made on blue fences in comparison to green fences (median difference of 2.5 bars). When only touched bars were included, a significant median difference of one bar was found. Mares (n?=?4) demonstrated more faults and had a significantly greater difference in touches and faults between the two colours than male horses (n?=?16). Repeating the same experiment with eight horses in an outdoor grass arena revealed no significant differences between the two colours. In order to draw any definite conclusions, more research concerning the colour perception, influence of contrast with the arena surface and sex of horse is required. PMID:25193409

Spaas, Julie; Helsen, Werner F; Adriaenssens, Maurits; Broeckx, Sarah; Duchateau, Luc; Spaas, Jan H

2014-10-01

132

Fine colour discrimination requires differential conditioning in bumblebees  

Microsoft Academic Search

Accurate recognition requires that visual systems must be able to discriminate between target and distractor stimuli. Flowers are learned and recognised by bees using visual cues including colour and shape. We investigated whether bees were able to learn to discriminate between colours differently depending upon absolute or differential conditioning. For absolute conditioning bees were rewarded with sucrose solution for visits

Adrian G. Dyer; Lars Chittka

2004-01-01

133

Estimating limits on colour vision performance in natural scenes  

E-print Network

633 Estimating limits on colour vision performance in natural scenes David H. FOSTER School scenes under different daylights. Three limits were estimated for each scene: the number of discriminable coloured surfaces under a single daylight, the relative frequency of metamerism across two daylights, and

Foster, David H.

134

Response of Phaseolus vulgaris L. to differing ozone regimes having identical total exposure  

NASA Astrophysics Data System (ADS)

Protocols were designed to test for differences in response of plants to ozone treatments having equal total exposure (concentration × time) but different exposure profiles Kidney beans ( Phaseolus vulgaris L., cv. California Dark Red) were exposed to ozone in controlled fumigation chambers within a greenhouse Four different ozone exposure profiles were used, each having the same total cumulative exposure (SUM00) and the same 7, 12 and 24 h seasonal means. The three exposure profiles which incorporated peak concentrations more severely impacted response parameters compared to a steady-state profile which did not exceed the National Ambient Air Quality Standard. Significant differences were found in percent necrotic leaf area, number of pods and top dry weight between exposure profiles. In additional analyses, the response parameters were regressed against seasonal cumulative ozone concentrations raised to powers of 0.33 and from 0.5 to 4 in steps of 0.5 in order to increase effective weighting of the higher concentrations. Total dry weight and leaf necrosis were best fit with the sum of the squared concentrations ( n = 2) while number of pods was best fit by the summed concentrations to the 3.5 power ( n = 3.5). These analyses suggest the peak ozone concentrations are important in determining plant response.

Musselman, Robert C.; Younglove, Theodore; McCool, Patrick M.

135

Specifying colour and maintaining colour accuracy for 3D printing  

Microsoft Academic Search

Advances in rapid prototyping technologies have led to the emergence of three-dimensional printers which can fabricate physical artefacts, including the application of surface colours. In light of these developments, this paper asserts that the need to print colour accurately is just as important for designers using three-dimensional colour printing as it is for two-dimensional inkjet printing. Parallels can be made

Carinna Parraman; Peter Walters; Brendan Reid; David Huson

2008-01-01

136

Odonata colour: more than meets the eye?  

Microsoft Academic Search

Interpretations of behavioural visual cues, based on human perception of colour, may mislead because of the difference in our visual range compared to other animals. Investigations into ultraviolet (UV) reflectance have shown that this can be an important mode of communication in many animals. The present study focused on 10 species of British Odonata. Digital photography was used to capture

Wendy E. Harris; Dan W. Forman; Roy D. Battell; Marie T. R. Battell; Alan K. Nelson; Paul F. Brain

2011-01-01

137

Genetic analyses of the human eye colours using a novel objective method for eye colour classification.  

PubMed

In this study, we present a new objective method for measuring the eye colour on a continuous scale that allows researchers to associate genetic markers with different shades of eye colour. With the use of the custom designed software Digital Iris Analysis Tool (DIAT), the iris was automatically identified and extracted from high resolution digital images. DIAT was made user friendly with a graphical user interface. The software counted the number of blue and brown pixels in the iris image and calculated a Pixel Index of the Eye (PIE-score) that described the eye colour quantitatively. The PIE-score ranged from -1 to 1 (brown to blue). The software eliminated the need for user based interpretation and qualitative eye colour categories. In 94% (570) of 605 analyzed eye images, the iris region was successfully extracted and a PIE-score was calculated. A very high correlation between the PIE-score and the human perception of eye colour was observed. The correlations between the PIE-scores and the six IrisPlex SNPs (HERC2 rs12913832, OCA2 rs1800407, SLC24A4 rs12896399, TYR rs1393350, SLC45A2 rs16891982 and IRF4 rs12203592) were analyzed in 570 individuals. Significant differences (p<10(-6)) in the PIE-scores of the individuals typed as HERC2 rs12913832 G (PIE=0.99) and rs12913832 GA (PIE=-0.71) or A (PIE=-0.87) were observed. We adjusted for the effect of HERC2 rs12913832 and showed that the quantitative PIE-scores were significantly associated with SNPs with minor effects (OCA2 rs1800407, SLC24A4 rs12896399 and TYR rs1393350) on the eye colour. We evaluated the two published prediction models for eye colour (IrisPlex [1] and Snipper[2]) and compared the predictions with the PIE-scores. We found good concordance with the prediction from individuals typed as HERC2 rs12913832 G. However, both methods had difficulties in categorizing individuals typed as HERC2 rs12913832 GA because of the large variation in eye colour in HERC2 rs12913832 GA individuals. With the use of the DIAT software and the PIE-score, it will be possible to automatically compare the iris colour of large numbers of iris images obtained by different studies and to perform large meta-studies that may reveal loci with small effects on the eye colour. PMID:23948321

Andersen, Jeppe D; Johansen, Peter; Harder, Stine; Christoffersen, Susanne R; Delgado, Mikaela C; Henriksen, Sarah T; Nielsen, Mette M; Sørensen, Erik; Ullum, Henrik; Hansen, Thomas; Dahl, Anders L; Paulsen, Rasmus R; Børsting, Claus; Morling, Niels

2013-09-01

138

Novel coloured flowers.  

PubMed

The floricultural industry has focused its attention primarily on the development of novel coloured and longer living cut flowers. The basis for this was laid down some years ago through the isolation of 'blue' genes and ethylene biosynthesis genes. Recently, a novel 'blue' gene has been discovered and yellow pigments were produced in petunias by addition of a new branch to the phenylpropanoid pathway. More insight was obtained into the sequestration of anthocyanin pigments into storage vacuoles. Significant progress has been achieved in the commercialisation of genetically modified flower varieties. PMID:10209139

Mol, J; Cornish, E; Mason, J; Koes, R

1999-04-01

139

The colour of bubbles  

NASA Astrophysics Data System (ADS)

Students of General Physics often complain that the course is too abstract and remote from daily life. As teachers, we emphasize that the abstract concepts of physics are indispensable for understanding our daily experiences, and we try to give the impression that quantitative descriptions can be achieved by adopting concrete mathematical expressions. Thus the abstract formulation is not to make physics more difficult, but to make it easier to grasp. We expect the students to learn to describe phenomena qualitatively using the concepts of physics, and to provide a quantitative description by manipulating the mathematical formulation. Here we supply one such example to calculate the colour of bubble films.

Huang, Ding-wei; Huang, Wei-neng; Tseng, Hsiang-chi

2005-11-01

140

Camouflage, communication and thermoregulation: lessons from colour changing organisms  

PubMed Central

Organisms capable of rapid physiological colour change have become model taxa in the study of camouflage because they are able to respond dynamically to the changes in their visual environment. Here, we briefly review the ways in which studies of colour changing organisms have contributed to our understanding of camouflage and highlight some unique opportunities they present. First, from a proximate perspective, comparison of visual cues triggering camouflage responses and the visual perception mechanisms involved can provide insight into general visual processing rules. Second, colour changing animals can potentially tailor their camouflage response not only to different backgrounds but also to multiple predators with different visual capabilities. We present new data showing that such facultative crypsis may be widespread in at least one group, the dwarf chameleons. From an ultimate perspective, we argue that colour changing organisms are ideally suited to experimental and comparative studies of evolutionary interactions between the three primary functions of animal colour patterns: camouflage; communication; and thermoregulation. PMID:19000973

Stuart-Fox, Devi; Moussalli, Adnan

2008-01-01

141

Ionospheric response to total solar eclipse of 22 July 2009 in different Indian regions  

NASA Astrophysics Data System (ADS)

The variability of ionospheric response to the total solar eclipse of 22 July 2009 has been studied analyzing the GPS data recorded at the four Indian low-latitude stations Varanasi (100% obscuration), Kanpur (95% obscuration), Hyderabad (84% obscuration) and Bangalore (72% obscuration). The retrieved ionospheric vertical total electron content (VTEC) shows a significant reduction (reflected by all PRNs (satellites) at all stations) with a maximum of 48% at Varanasi (PRN 14), which decreases to 30% at Bangalore (PRN 14). Data from PRN 31 show a maximum of 54% at Kanpur and 26% at Hyderabad. The maximum decrement in VTEC occurs some time (2-15 min) after the maximum obscuration. The reduction in VTEC compared to the quiet mean VTEC depends on latitude as well as longitude, which also depends on the location of the satellite with respect to the solar eclipse path. The amount of reduction in VTEC decreases as the present obscuration decreases, which is directly related to the electron production by the photoionization process. The analysis of electron density height profile derived from the COSMIC (Constellation Observing System for Meteorology, Ionosphere & Climate) satellite over the Indian region shows significant reduction from 100 km altitude up to 800 km altitude with a maximum of 48% at 360 km altitude. The oscillatory nature in total electron content data at all stations is observed with different wave periods lying between 40 and 120 min, which are attributed to gravity wave effects generated in the lower atmosphere during the total solar eclipse.

Kumar, S.; Singh, A. K.; Singh, R. P.

2013-09-01

142

Effects of different fungal elicitors on growth, total carotenoids and astaxanthin formation by Xanthophyllomyces dendrorhous.  

PubMed

Six fungal elicitors prepared from Rhodotorula rubra, Rhodotorula glutinis, Panus conchatus, Coriolus versicolor, Mucor mucedo, Mortieralla alpina M-23 were examined to determine their effects on the growth, total carotenoids and astaxanthin formation by Xanthophyllomyces dendrorhous. The results showed that different fungal elicitor could cause diversely stimulating effects. Among the fungal elicitors tested, the M. mucedo elicitor concentration of 30 mg l(-1) promoted the biomass and total carotenoids yield most remarkably, resulting in 69.81+/-6.00% and 78.87+/-4.15% higher than the control, respectively. At the concentration of 30 mg l(-1), R. glutinis elicitor stimulated the highest astaxanthin yield with a 90.60+/-5.98% increase compared to the control. The R. rubra elicitor concentration of 30 mg l(-1) resulted in the optimal total carotenoids and astaxanthin content to be 42.24+/-0.49% and 69.02+/-0.72% higher than the control, respectively. At the concentration of 30 mg l(-1), R. rubra elicitor gave the highest increase in the ratio of astaxanthin in total carotenoids by 18.85+/-0.11% of the control. PMID:16154499

Wang, Wenjun; Yu, Longjiang; Zhou, Pengpeng

2006-01-01

143

Optimality of the basic colour categories for classification  

PubMed Central

Categorization of colour has been widely studied as a window into human language and cognition, and quite separately has been used pragmatically in image-database retrieval systems. This suggests the hypothesis that the best category system for pragmatic purposes coincides with human categories (i.e. the basic colours). We have tested this hypothesis by assessing the performance of different category systems in a machine-vision task. The task was the identification of the odd-one-out from triples of images obtained using a web-based image-search service. In each triple, two of the images had been retrieved using the same search term, the other a different term. The terms were simple concrete nouns. The results were as follows: (i) the odd-one-out task can be performed better than chance using colour alone; (ii) basic colour categorization performs better than random systems of categories; (iii) a category system that performs better than the basic colours could not be found; and (iv) it is not just the general layout of the basic colours that is important, but also the detail. We conclude that (i) the results support the plausibility of an explanation for the basic colours as a result of a pressure-to-optimality and (ii) the basic colours are good categories for machine vision image-retrieval systems. PMID:16849219

Griffin, Lewis D

2005-01-01

144

Computational Production of Colour Harmony. Part 1: A Prototype Colour  

E-print Network

with the human expression of personal taste. Our Colour Harmoniser is a research tool that is meant to explore 5 July 2011; accepted 24 August 2011 Abstract: Although web page and computer interface devel- opers the possibility of automatically producing har- monious and usable user interface colour schemes by modeling

Marsland, Stephen

145

Rapid mixing for lattice colourings with fewer colours  

Microsoft Academic Search

We provide an optimally mixing Markov chain for 6-colourings of the square lattice on rectangular regions with free, fixed, or toroidal boundary conditions. This implies that the uniform distribution on the set of such colourings has strong spatial mixing, so the six-state Potts antiferromagnet has a finite correlation length and a unique Gibbs measure at zero temperature. Four and five

Dimitris Achlioptas; Mike Molloy; Cristopher Moore; Frank Van Bussel

2005-01-01

146

Improper Colourings of Unit Disk Graphs  

Microsoft Academic Search

Abstract: Motivated by a satellite communications problem, we consider a generalised colouring problem on unit disk graphs. A colouring is k-improper if no vertex receives the same colour as k+1 of its neighbours. The k-improper chromatic number ´, for unit interval graphs. Key-words: improper colouring, defective colouring, unit disk graph, interval graph, triangular

Frédéric Havet; Ross J. Kang; Jean-sébastien Sereni

2005-01-01

147

Measuring colour rivalry suppression in amblyopia  

PubMed Central

AIMS—To determine if the colour rivalry suppression is an index of the visual impairment in amblyopia and if the stereopsis and fusion evaluator (SAFE) instrument is a reliable indicator of the difference in visual input from the two eyes.?METHODS—To test the accuracy of the SAFE instrument for measuring the visual input from the two eyes, colour rivalry suppression was measured in six normal subjects. A test neutral density filter (NDF) was placed before one eye to induce a temporary relative afferent defect and the subject selected the NDF before the fellow eye to neutralise the test NDF. In a non-paediatric private practice, 24 consecutive patients diagnosed with unilateral amblyopia were tested with the SAFE. Of the 24 amblyopes, 14 qualified for the study because they were able to fuse images and had no comorbid disease. The relation between depth of colour rivalry suppression, stereoacuity, and interocular difference in logMAR acuity was analysed.?RESULTS—In normal subjects, the SAFE instrument reversed temporary defects of 0.3 to 1.8 log units to within 0.6 log units. In amblyopes, the NDF to reverse colour rivalry suppression was positively related to interocular difference in logMAR acuity (?=1.21, p<0.0001), and negatively related to stereoacuity (?=?0.16, p=0.019). The interocular difference in logMAR acuity was negatively related to stereoacuity (?=?0.13, p=0.009).?CONCLUSIONS—Colour rivalry suppression as measured with the SAFE was found to agree closely with the degree of visual acuity impairment in non-paediatric patients with amblyopia.?? PMID:10535858

Hofeldt, T.; Hofeldt, A.

1999-01-01

148

Odour and colour polymorphism in the food-deceptive orchid Dactylorhiza romana  

Microsoft Academic Search

The food deceptive orchid, Dactylorhiza romana (Sebastiani) Soó exhibits a colour polymorphism with yellow, red, and intermediate orange morphs. In this study we tested\\u000a if floral odour differed among the three distinct colour morphs. We identified 23 odour compounds in D. romana, and all of them occurred in the three colour morphs. Monoterpenes dominated the floral scent. On the basis

C. C. Salzmann; F. P. Schiestl

2007-01-01

149

Kinetics of colour change of double concentrated tomato paste during thermal treatment  

Microsoft Academic Search

The kinetics of the colour change of double concentrated tomato paste during heating was studied. The Hunter ‘L’, ‘a’, ‘b’ tristimulus values were measured to characterise the colour, and colour difference (?E); saturation index (SI) and ‘ab’ ratio were calculated from those values. The kinetic study was performed using the capillary tube method with temperatures ranging from 70.0 to 100.0

J. A. Barreiro; M. Milano; A. J. Sandoval

1997-01-01

150

Reproductive biology of Geranium sessiliflorum. II. The genetics and morph frequencies of the leaf colour polymorphism  

Microsoft Academic Search

In New Zealand three leaf colour morphs of Geranium sessiliflorum are found: brown, green, and intermediate olive. This polymorphism was investigated using controlled crosses between plants of the different colours, selfs, and harvesting of seeds produced after open pollination in the field and in cultivated plants. The leaf colour trimorphism is considered to be determined by one locus with two

M. Philipp

1987-01-01

151

Implementation and characterization of a fibre-optic colour sensor  

NASA Astrophysics Data System (ADS)

In this paper the implementation of a fibre-optic sensor for colour detection based on reflective colour sensing is proposed. The sensor consists of three plastic optical fibres emitting red, green and blue components and one optical fibre collecting light reflected from the object. Red, green and blue LEDs are excited at different frequencies. In this way detection of the reflected signal is achieved with only one photodetector and three bandpass filters. Bandpass filters are implemented as digital IIR (infinite impulse response) filters on the microcontroller. Results obtained from the proposed sensor are compared with commercial available colour sensors and the results are satisfactory. Analyses of the sensor performance both in RGB and HSV colour space are done. The proposed solution shows that in specific applications by using the HSV model the sensor can be used both as a colour and distance sensor.

Baji?, Jovan S.; Stupar, Dragan Z.; Daki?, Bojan M.; Manojlovi?, Lazo M.; Slankamenac, Miloš P.; Živanov, Miloš B.

2014-09-01

152

Demographic Variation between Colour Patterns in a Temperate Protogynous Hermaphrodite, the Ballan Wrasse Labrus bergylta  

PubMed Central

Fish populations are often treated as homogeneous units in typical fishery management, thereby tacitly ignoring potential intraspecific variation which can lead to imprecise management rules. However, intraspecific variation in life-history traits is widespread and related to a variety of factors. We investigated the comparative age-based demography of the two main colour patterns of Labrus bergylta (plain and spotted, which coexist in sympatry), a commercially valuable resource in the NE Atlantic. Individuals were aged based on otolith readings after validating the annual periodicity of annuli deposition. The relationships between the otolith weight and fish age and between otolith length and fish length were strong but differed between colour patterns. The fit of the growth models to the age and length data resulted in divergent growth curves between colour morphotypes and between sexes. Males and spotted individuals attained larger mean asymptotic sizes (Linf) than females and plain individuals, respectively, but converged to them more slowly (smaller k). Estimates of mortality based on catch curves from two independent datasets provided a global total mortality (Z) of 0.35 yr–1, although Z was larger in plain and female individuals. Overall, the results of this research have direct implications for management of L. bergylta and, as a precautionary measure, we recommend considering both colour patterns as two different management units. PMID:24058404

Villegas-Rios, David; Alonso-Fernandez, Alexandre; Fabeiro, Marina; Banon, Rafael; Saborido-Rey, Fran

2013-01-01

153

Quantitative Luminance And Colour Representation With CRT Displays  

NASA Astrophysics Data System (ADS)

Colour displays in image processing admit grey scales as well as colour scales for the visual representation of image information. Pseudocolours can be used to enhance the discriminability of different parts of the image. Luminance scales, on the other hand, are preferred for representing fine detail as human colour vision is limited to relatively low spatial frequencies. In the present paper, the generation of quantitative luminance and colour scales with CRT displays is discussed. This includes the colour characteristics of CRTs as well as a recapitulation of the CIE 1931 (X, Y, Z) tristimulus colorimetry system. The CIE 1976 UCS diagram (u', v') is used as an approximation to a perceptually uniform representation of chromaticity. On this basis, it is shown how, for each pixel, luminance and colour (hue) can be chosen independently. In order to add colour as a further visual dimension to greyscale images, a set of equiluminant hues is proposed for each luminance level. The hues are chosen from equidistant steps around a circle in the (u', v') chromaticity diagram. This choice of colours is particularly suitable for the visual representation of a cyclic quantity like phase angle.

Brettel, Hans

1989-03-01

154

Children's Models about Colours in Nahuatl-Speaking Communities  

NASA Astrophysics Data System (ADS)

This paper presents the development and structure of indigenous children's ideas about mixing colours as well as their ideas about each colour, derived from their traditions. The children were interviewed both at school and outside it, and an educational proposal was implemented. Ideas expressed in the school context were analysed using the partial possible model, which states that the inferences and explanations used to describe a subject consist of constricting ideas, rules of correspondence, and a set of phenomenological inferences about processes. After identifying these components in the children's ideas, we developed models to describe their conceptions about mixing colours. We employed a different approach to analyse children's ideas related to their cultural context. The results showed that children change from a conception that focuses on colours as entities that do not change and as properties of objects (model 1) to the idea that colour represents a quality of substances or objects that can be modified by mixing colours (model 2). Cultural context analysis showed that stories are independent from one another and that they are not connected to colour mixing processes, only to the actions of colour on people. We concluded that students generate independent constructions between school and cultural knowledge.

Gallegos-Cázares, Leticia; Flores-Camacho, Fernando; Calderón-Canales, Elena; Perrusquía-Máximo, Elvia; García-Rivera, Beatriz

2014-10-01

155

Behavioural evidence of colour vision in free flying stingless bees.  

PubMed

Colour vision was first demonstrated with behavioural experiments in honeybees 100 years ago. Since that time a wealth of quality physiological data has shown a highly conserved set of trichromatic colour receptors in most bee species. Despite the subsequent wealth of behavioural research on honeybees and bumblebees, there currently is a relative dearth of data on stingless bees, which are the largest tribe of the eusocial bees comprising of more than 600 species. In our first experiment we tested Trigona cf. fuscipennis, a stingless bee species from Costa Rica in a field setting using the von Frisch method and show functional colour vision. In a second experiment with these bees, we use a simultaneous colour discrimination test designed for honeybees to enable a comparative analysis of relative colour discrimination. In a third experiment, we test in laboratory conditions Tetragonula carbonaria, an Australian stingless bee species using a similar simultaneous colour discrimination test. Both stingless bee species show relatively poorer colour discrimination compared to honeybees and bumblebees; and we discuss the value of being able to use these behavioural methods to efficiently extend our current knowledge of colour vision and discrimination in different bee species. PMID:24519371

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

2014-06-01

156

Colour mimicry and sexual deception by Tongue orchids ( Cryptostylis)  

NASA Astrophysics Data System (ADS)

Typically, floral colour attracts pollinators by advertising rewards such as nectar, but how does colour function when pollinators are deceived, unrewarded, and may even suffer fitness costs? Sexually deceptive orchids are pollinated only by male insects fooled into mating with orchid flowers and inadvertently transferring orchid pollinia. Over long distances, sexually deceptive orchids lure pollinators with counterfeit insect sex pheromones, but close-range deception with colour mimicry is a tantalising possibility. Here, for the first time, we analyse the colours of four sexually deceptive Cryptostylis orchid species and the female wasp they mimic ( Lissopimpla excelsa, Ichneumonidae), from the perspective of the orchids’ single, shared pollinator, male Lissopimpla excelsa. Despite appearing different to humans, the colours of the orchids and female wasps were effectively identical when mapped into a hymenopteran hexagonal colour space. The orchids and wasps reflected predominantly red-orange wavelengths, but UV was also reflected by raised bumps on two orchid species and by female wasp wings. The orchids’ bright yellow pollinia contrasted significantly with their overall red colour. Orchid deception may therefore involve accurate and species-specific mimicry of wavelengths reflected by female wasps, and potentially, exploitation of insects’ innate attraction to UV and yellow wavelengths. In general, mimicry may be facilitated by exploiting visual vulnerabilities and evolve more readily at the peripheries of sensory perception. Many sexually deceptive orchids are predominantly red, green or white: colours that are all potentially difficult for hymenoptera to detect or distinguish from the background.

Gaskett, A. C.; Herberstein, M. E.

2010-01-01

157

Deuterium for estimating total body water and turnover rates in turkeys exposed to different incubation treatments.  

PubMed

Total water intake (TWI) in poultry can be influenced by various factors. Recommendations for water requirements are usually reported on a flock basis without considering individual variation. In the present study, a total of 18 turkeys were used to measure water intake over a 1-wk period starting at 15 wk of age by applying the deuterium dilution technique. Poults originated from eggs exposed to different incubation treatments, with eggs incubated at normal temperature (37.5 degrees C) and eggs subjected to 38.5 degrees C at embryonic d 9 to 12. Experimental birds were kept in flocks of 22 to 30 birds separated by sex and treatment. Feed and water were provided ad libitum. Incubation treatment had no significant effect on any of the parameters investigated (BW, daily gain, water turnover rate, total body water, TWI), whereas sex exerted a significant effect on nearly all traits. Total body water ranged between 60 and 65% of BW, with significantly (P < 0.05) greater values for toms (63.2%) than for hens (60.9%). Males had approximately 30% greater water influxes than females (1,054 +/- 198 vs. 742 +/- 153 mL/d, mean +/- SD). However, the significant influence of sex was eliminated (P = 0.464) when TWI was expressed as grams per kilogram of BW (76 +/- 18 vs. 70 +/- 12 mL/kg of BW; males vs. females). Water consumed averaged 837 mL in male and 569 mL per day in female birds. The present results suggest that the isotope dilution method offers a viable method to measure individual water intake, which can be used for establishing reference values for water consumption in group-housed turkeys. PMID:19038819

Riek, A; Gerken, M; Werner, C; Gonde, A

2008-12-01

158

Discriminating colours under LED illumination  

Microsoft Academic Search

We measured the discrimination efficiency of three LED clusters (RGB, RGB + Amber, cool White + Amber) using the desaturated Lanthony-Panel D15 colour vision test. Compared with a continuous spectrum illumination, all LED clusters impair colour discrimination, with a severe impairment for RGB LED cluster. 1. PURPOSE LED technology offers light sources with narrow spectrum in the visible range. At

Françoise Viénot; Elodie Mahler; Lucile Serreault; Margalith Harrar; Jean-Jacques Ezrati; Pierre Pérignon; Alain Bricoune

159

Reversible colour change in Arthropoda.  

PubMed

The mechanisms and functions of reversible colour change in arthropods are highly diverse despite, or perhaps due to, the presence of an exoskeleton. Physiological colour changes, which have been recorded in 90 arthropod species, are rapid and are the result of changes in the positioning of microstructures or pigments, or in the refractive index of layers in the integument. By contrast, morphological colour changes, documented in 31 species, involve the anabolism or catabolism of components (e.g. pigments) directly related to the observable colour. In this review we highlight the diversity of mechanisms by which reversible colour change occurs and the evolutionary context and diversity of arthropod taxa in which it has been observed. Further, we discuss the functions of reversible colour change so far proposed, review the limited behavioural and ecological data, and argue that the field requires phylogenetically controlled approaches to understanding the evolution of reversible colour change. Finally, we encourage biologists to explore new model systems for colour change and to engage scientists from other disciplines; continued cross-disciplinary collaboration is the most promising approach to this nexus of biology, physics, and chemistry. PMID:24495279

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

2014-11-01

160

Light Filters of Coloured `Perspex'  

Microsoft Academic Search

LIGHT filters of coloured glass and gelatin are in common use for visual and photoelectric photometers. They are satisfactory, on the whole; but the glass filters are easily broken, and those of gelatin require to be mounted between glass to protect them from water. The transparent polymethyl methacrylate `Perspex' is now obtainable in several colours and in sheets. This material

E. J. King; S. Ventura

1951-01-01

161

Associating Colours with Musical Genres  

Microsoft Academic Search

To study visualizations for music, we arranged a set of online questionnaires on how people map various visual properties to certain musical attributes. This paper presents the results of a questionnaire that concentrated on how people map colours to musical genres. The participants were shown 12 colours one at a time, and asked which of listed 18 genres they associated

Jukka Holm; Antti Aaltonen; Harri Siirtola

2009-01-01

162

The Four-Colour Problem  

Microsoft Academic Search

THE correctness of the statement that any plane map may always be tinted with four colours in such a way that two areas meeting on the same boundary never have the same colour has always been admitted since Möbius mentioned it in 1840, although no mathematical proof of this theorem has yet been firmly established. I think I have found

S. M. de Backer

1944-01-01

163

Influence of the apparent molecular size of aquatic humic substances on colour removal by coagulation and filtration.  

PubMed

This study aims to verify the influence of the apparent molecular size of aquatic humic substances (AHSs) on the effectiveness of coagulation with aluminium sulphate and ferric chloride. Coagulation-filtration tests using the jar test and bench-scale sand filters were carried out with water samples having a true colour of approximately 100 Hazen units and prepared with AHSs of different molecular sizes. Stability diagrams are presented showing regions of > or = 90% and > or = 95% apparent colour removal delineated for each water sample using plots of total metal ion concentration (Al3+ and Fe3+) versus coagulation pH. To achieve the same degree of colour removal, the water samples with smaller apparent molecular sizes and a higher percentage of fulvic acids required higher dosages of both aluminium sulphate and ferric chloride. PMID:22439564

Rigobello, Eliane Sloboda; Dantas, Angela Di Bernardo; Di Bernardo, Luiz; Vieira, Eny Maria

2011-12-01

164

Outcomes of the Different Types of Total Knee Arthroplasty with the Identical Femoral Geometry  

PubMed Central

Purpose There are controversies around the role of the posterior cruciate ligament and the effect of design modifications for high flexion in total knee arthroplasty (TKA). So, we compared the clinical outcomes of the cruciate retaining (CR), posterior stabilized (PS), and high flexion posterior stabilized (F-PS) designs in TKA with identical femoral geometry. Materials and Methods One hundred seventy nine knees with 3 different types of prostheses after a minimum 5-year follow-up were enrolled in this retrospective study: 45 with CR, 40 with PS and 94 with F-PS. The mean ages of these groups were 65.7, 67.2, and 67.5, and the mean durations of follow-up were 8.1, 8.0, and 6.8 years, respectively. We compared the range of motion, functional outcomes, and radiographic measurements at the 2-year follow-up and last follow-up. Results The maximal flexion angle was significantly lower in the CR group than the F-PS group at the 2-year follow-up. However, there was no significant difference at the last follow-up. Functional outcomes and survival rate of the three groups were similar at the last follow-up. Conclusions Three different types of TKAs (CR, PS and F-PS) with identical femoral geometry showed similar mid-term outcomes with regard to the range of motion, functional outcomes and survival rate. PMID:23269959

Lee, Sang Min; Seong, Sang Cheol; Lee, Sahnghoon; Choi, Won Chul

2012-01-01

165

MAXIMUM NUMBER OF REPETITIONS, TOTAL WEIGHT LIFTED AND NEUROMUSCULAR FATIGUE IN INDIVIDUALS WITH DIFFERENT TRAINING BACKGROUNDS  

PubMed Central

The aim of this study was to evaluate the performance, as well as neuromuscular activity, in a strength task in subjects with different training backgrounds. Participants (n = 26) were divided into three groups according to their training backgrounds (aerobic, strength or mixed) and submitted to three sessions: (1) determination of the maximum oxygen uptake during the incremental treadmill test to exhaustion and familiarization of the evaluation of maximum strength (1RM) for the half squat; (2) 1RM determination; and (3) strength exercise, four sets at 80% of the 1RM, in which the maximum number of repetitions (MNR), the total weight lifted (TWL), the root mean square (RMS) and median frequency (MF) of the electromyographic (EMG) activity for the second and last repetition were computed. There was an effect of group for MNR, with the aerobic group performing a higher MNR compared to the strength group (P = 0.045), and an effect on MF with a higher value in the second repetition than in the last repetition (P = 0.016). These results demonstrated that individuals with better aerobic fitness were more fatigue resistant than strength trained individuals. The absence of differences in EMG signals indicates that individuals with different training backgrounds have a similar pattern of motor unit recruitment during a resistance exercise performed until failure, and that the greater capacity to perform the MNR probably can be explained by peripheral adaptations. PMID:24744479

Azevedo, Neto R.M.; Julio, U.F.; Andreato, L.V.; Pinto e Silva, C.M.; Hardt, F.; Franchini, E.

2013-01-01

166

Relationship between nine haloacetic acids with total organic halogens in different experimental conditions.  

PubMed

The effects of pH and bromide ion concentration on the formation of nine haloacetic acids (HAAs) and total organic halogens (TOX) in chlorinated drinking water have been evaluated. In an extensive study, the relationships of nine HAAs with TOX have been investigated. Honesty Significant Differences test (HSD) and ANOVA tests were used for the statistical analyses. The study determined the concentration range of nine HAAs as of a percentage of TOX at varying experimental conditions. Statistical analyses showed that the parameters pH and Br had significant effects on the formation of nine HAAs and TOX. This study also showed that brominated and mixed species of HAAs would be dominant in the presence of high bromide ion concentration which contributes a high percentage of the TOX. The results of this study could be used to set up a maximum contaminant level of TOX as a water quality standard for chlorination by-products. PMID:23551829

Pourmoghadas, Hossein; Kinman, Riley N

2013-01-01

167

A Novel Weighted Total Difference Based Image Reconstruction Algorithm for Few-View Computed Tomography  

PubMed Central

In practical applications of computed tomography (CT) imaging, due to the risk of high radiation dose imposed on the patients, it is desired that high quality CT images can be accurately reconstructed from limited projection data. While with limited projections, the images reconstructed often suffer severe artifacts and the edges of the objects are blurred. In recent years, the compressed sensing based reconstruction algorithm has attracted major attention for CT reconstruction from a limited number of projections. In this paper, to eliminate the streak artifacts and preserve the edge structure information of the object, we present a novel iterative reconstruction algorithm based on weighted total difference (WTD) minimization, and demonstrate the superior performance of this algorithm. The WTD measure enforces both the sparsity and the directional continuity in the gradient domain, while the conventional total difference (TD) measure simply enforces the gradient sparsity horizontally and vertically. To solve our WTD-based few-view CT reconstruction model, we use the soft-threshold filtering approach. Numerical experiments are performed to validate the efficiency and the feasibility of our algorithm. For a typical slice of FORBILD head phantom, using 40 projections in the experiments, our algorithm outperforms the TD-based algorithm with more than 60% gains in terms of the root-mean-square error (RMSE), normalized root mean square distance (NRMSD) and normalized mean absolute distance (NMAD) measures and with more than 10% gains in terms of the peak signal-to-noise ratio (PSNR) measure. While for the experiments of noisy projections, our algorithm outperforms the TD-based algorithm with more than 15% gains in terms of the RMSE, NRMSD and NMAD measures and with more than 4% gains in terms of the PSNR measure. The experimental results indicate that our algorithm achieves better performance in terms of suppressing streak artifacts and preserving the edge structure information of the object. PMID:25275385

Yu, Wei; Zeng, Li

2014-01-01

168

A novel weighted total difference based image reconstruction algorithm for few-view computed tomography.  

PubMed

In practical applications of computed tomography (CT) imaging, due to the risk of high radiation dose imposed on the patients, it is desired that high quality CT images can be accurately reconstructed from limited projection data. While with limited projections, the images reconstructed often suffer severe artifacts and the edges of the objects are blurred. In recent years, the compressed sensing based reconstruction algorithm has attracted major attention for CT reconstruction from a limited number of projections. In this paper, to eliminate the streak artifacts and preserve the edge structure information of the object, we present a novel iterative reconstruction algorithm based on weighted total difference (WTD) minimization, and demonstrate the superior performance of this algorithm. The WTD measure enforces both the sparsity and the directional continuity in the gradient domain, while the conventional total difference (TD) measure simply enforces the gradient sparsity horizontally and vertically. To solve our WTD-based few-view CT reconstruction model, we use the soft-threshold filtering approach. Numerical experiments are performed to validate the efficiency and the feasibility of our algorithm. For a typical slice of FORBILD head phantom, using 40 projections in the experiments, our algorithm outperforms the TD-based algorithm with more than 60% gains in terms of the root-mean-square error (RMSE), normalized root mean square distance (NRMSD) and normalized mean absolute distance (NMAD) measures and with more than 10% gains in terms of the peak signal-to-noise ratio (PSNR) measure. While for the experiments of noisy projections, our algorithm outperforms the TD-based algorithm with more than 15% gains in terms of the RMSE, NRMSD and NMAD measures and with more than 4% gains in terms of the PSNR measure. The experimental results indicate that our algorithm achieves better performance in terms of suppressing streak artifacts and preserving the edge structure information of the object. PMID:25275385

Yu, Wei; Zeng, Li

2014-01-01

169

Perception of colour in unilateral tritanopia.  

PubMed Central

The unilateral tritanope described in the previous paper (Alpern, Kitahara & Krantz, 1983) was able to match every narrow-band light presented to his tritanopic eye with lights from a tristimulus colorimeter viewed in the adjacent field by the normal eye. In two regions of the spectrum (called isochromes) physically identical lights appeared identical to the observer's two eyes. One isochrome was close to 'blue' for the normal eye, the other was in the long-wave spectral region seen by the normal eye predominantly as 'red'. Between these isochromes the normal eye required less than spectral purity to match, dropping to near zero purity at 560-570 nm. A mixture of the two isochromes that appeared purple to the normal eye appeared neutral to the tritanopic eye. Hence dichoptic matches grossly violate Grassmann's additivity law. For the normal eye colour naming conformed to typical normal results. For the tritanopic eye the results were coherent with those found by dichoptic matching: the spectrum was divided into two regions by the achromatic neutral band. To the short-wave side, only the colour names 'blue' and 'white' were ever used. To the long-wave side the predominant colour names were 'red' and 'white' with some 'yellow'. Spectral lights appeared neither 'red-blue' nor greenish. Surrounding the test with an annulus either 430 nm, 650 nm, or a mixture of these, fails to induce any greenish appearance, although the achromatic band shifted in the expected directions. It is concluded that there must be exactly three functionally independent, essentially non-linear central codes for colour perception, and that these codes are different from those suggested in existing theories of colour perception. PMID:6603509

Alpern, M; Kitahara, K; Krantz, D H

1983-01-01

170

A novel illumination-invariant colour constancy algorithm  

NASA Astrophysics Data System (ADS)

The human brain is able to extract the colour of objects no matter the existing illumination conditions which may affect the appearance of their colour. For a person, an object that is red, it will be red regardless of the type of illumination source. However, for a computer algorithm to achieve the same task is not as simple. For vision and robotics applications were feature extraction is essential having such an algorithm is crucial. It is well known from the literature that the colour of an object does not only depend on the chemical composition and shape of its surface but also on the illumination conditions, the intensity, number, location and colour of the sources of illumination as well as the intrinsic and extrinsic characteristics of the sensor used. Based on that knowledge, we propose a simple colour constancy algorithm that uses the quaternion representation of each pixel in the image instead of the commonly used RGB model. We assume linearity in the reception of the luminance spectrum of the charge-coupled device of the camera before variations in the illumination. We have tested our colour constancy algorithm in a variety of images containing different colour objects under different illumination conditions. Our experimental results show the feasibility of the proposed method.

Torres-Méndez, L. A.; Quiñones Muñoz, M. L.; Olaya-Benítez, E. J.

2011-08-01

171

Colour Spaces for Colour Transfer Erik Reinhard and Tania Pouli  

E-print Network

, Correlation 1 Introduction Colour is one of the main image attributes used in art, photography and visuali of the L, M and S cones in the human retina (the letters stand for Long, Medium and Short wavelength

Reinhard, Erik

172

Introduction Colour-impaired vision, where certain colours cannot be  

E-print Network

these colours. Dark green, brown, orange, and dark red in the first row appear as almost indistinguishable olive, where he produces print graphics for daily publication and interactive web graphics. nvkelso

Jenny, Bernhard

173

Linguistic Determinants of Word Colouring in Grapheme-Colour Synaesthesia  

Microsoft Academic Search

Previous studies of grapheme-colour synaesthesia have suggested that words tend to be coloured by their initial letter or initial vowel (e.g., Baron-Cohen et al., 1993; Ward et al., 2005). We examine this assumption in two ways. First, we show that letter position and syllable stress have been confounded, such that the initial letters of a word are often in stressed

Julia Simner; Louise Glover; Alice Mowat

2006-01-01

174

Physicochemical and sensory characteristics of whey protein hydrolysates generated at different total solids levels.  

PubMed

Whey protein hydrolysates were generated at different total solids (TS) levels (50-300 g/l) using the commercially available proteolytic preparation Debitrase HYW20, while enzyme to substrate ratio, pH and temperature were maintained constant. Hydrolysis proceeded at a faster rate at lower TS reaching a degree of hydrolysis (DH) of 16.6% at 300 g TS/l, compared with a DH of 22.7% at 50 g TS/l after 6 h hydrolysis. The slower breakdown of intact whey proteins at high TS was quantified by gel-permeation HPLC. Reversed-phase (RP) HPLC of hydrolysate samples of equivalent DH (approximately 15%) generated at different TS levels indicated that certain hydrophobic peptide peaks were present at higher levels in hydrolysates generated at low TS. Sensory evaluation showed that hydrolysates with equivalent DH values were significantly (P < 0.0005) less bitter when generated at 300 g TS/l (mean bitterness score = 25.4%) than hydrolysates generated at 50 g TS/l (mean bitterness score = 39.9%). A specific hydrophobic peptide peak present at higher concentrations in hydrolysates generated at low TS was isolated and identified as beta-lactoglobulin f(43-57), a fragment having the physical and chemical characteristics of a bitter peptide. PMID:15909678

Spellman, David; O'Cuinn, Gerard; FitzGerald, Richard J

2005-05-01

175

Optimal colour quality of LED clusters based on memory colours.  

PubMed

The spectral power distributions of tri- and tetrachromatic clusters of Light-Emitting-Diodes, composed of simulated and commercially available LEDs, were optimized with a genetic algorithm to maximize the luminous efficacy of radiation and the colour quality as assessed by the memory colour quality metric developed by the authors. The trade-off of the colour quality as assessed by the memory colour metric and the luminous efficacy of radiation was investigated by calculating the Pareto optimal front using the NSGA-II genetic algorithm. Optimal peak wavelengths and spectral widths of the LEDs were derived, and over half of them were found to be close to Thornton's prime colours. The Pareto optimal fronts of real LED clusters were always found to be smaller than those of the simulated clusters. The effect of binning on designing a real LED cluster was investigated and was found to be quite large. Finally, a real LED cluster of commercially available AlGaInP, InGaN and phosphor white LEDs was optimized to obtain a higher score on memory colour quality scale than its corresponding CIE reference illuminant. PMID:21451716

Smet, Kevin; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter

2011-03-28

176

Atmospheric electric field effect for total NM intensity and different multiplicities on Mt Hermon  

NASA Astrophysics Data System (ADS)

Cosmic rays (CR) are an important element of space weather and instrument of space weather forecasting. From this point of view, it is necessary to take into account all factors influencing CR intensity. One of these important factors is the influence of atmospheric electric fields (AEF) during thunderstorms on CR intensity. This is caused by local acceleration (or deceleration, depending on the direction of the AEF and the sign of charged particles) of secondary CR particles (mostly muons and electrons, for CR observations in the low atmosphere or underground). We analysed one minute data on AEF obtained by the ESF-1000 sensor in our observatory on Mt. Hermon, and one minute neutron monitor data corrected on barometric effects and on the effect of snow. While AEF does not influence neutrons, we found significant effects in the observed total neutron intensity and in the intensities of different multiplicities. This is caused mostly by soft negative muons, captured by nuclei of lead (instead of the atom’s electrons) with the formation of mesoatoms. While the cross section of muons relative to strong interactions is very small (the same order as for neutrino), because the captured muon moves about inside the nucleus with very high density, the probability of muon interaction with nucleus is higher than the decay of muon. As result of this interaction the total energy of the rest muon about 100 MeV goes to the excitation of lead nuclei, with emanation of a few neutrons which are detected by the neutron monitor. Therefore, a neutron monitor is an ideal detector for separating positive and negative soft muons (without using a big magnetic system). We obtained results for positively and negatively directed AEF and show existing significant AEF influence on CR intensithttps://www.cospar-assembly.org/user/download2.php?id=29566&type=previewy, biggest for small multiplicities. We give a theoretical explanation of obtained results.

Lev, Dorman; Zukerman, Igor; Pustilnik, Lev; Dai, Uri; Shternlib, Abracham; Shai Applbaum, David; Kazantsev, Vasilii; Kozliner, Lev; Ben Israel, Isaac

177

Colour Constancy Across the Life Span: Evidence for Compensatory Mechanisms  

PubMed Central

It is well known that the peripheral visual system declines with age: the yellowing of the lens causes a selective reduction of short-wavelength light and sensitivity losses occur in the cone receptor mechanisms. At the same time, our subjective experience of colour does not change with age. The main purpose of this large-scale study (n?=?185) covering a wide age range of colour-normal observers (18–75 years of age) was to assess the extent to which the human visual system is able to compensate for the changes in the optical media and at which level of processing this compensation is likely to occur. We report two main results: (1) Supra-threshold parafoveal colour perception remains largely unaffected by the age-related changes in the optical media (yellowing of the lens) whereas our ability to discriminate between small colour differences is compromised with an increase in age. (2) Significant changes in colour appearance are only found for unique green settings under daylight viewing condition which is consistent with the idea that the yellow-blue mechanism is most affected by an increase in age due to selective attenuation of short-wavelength light. The data on the invariance of hue perception, in conjunction with the age-related decline in chromatic sensitivity, provides evidence for compensatory mechanisms that enable colour-normal human observers a large degree of colour constancy across the life span. These compensatory mechanisms are likely to originate at cortical sites. PMID:23667689

Wuerger, Sophie

2013-01-01

178

Three-dimensional plasmonic stereoscopic prints in full colour.  

PubMed

Metal nanostructures can be designed to scatter different colours depending on the polarization of the incident light. Such spectral control is attractive for applications such as high-density optical storage, but challenges remain in creating microprints with a single-layer architecture that simultaneously enables full-spectral and polarization control of the scattered light. Here we demonstrate independently tunable biaxial colour pixels composed of isolated nanoellipses or nanosquare dimers that can exhibit a full range of colours in reflection mode with linear polarization dependence. Effective polarization-sensitive full-colour prints are realized. With this, we encoded two colour images within the same area and further use this to achieve depth perception by realizing three-dimensional stereoscopic colour microprint. Coupled with the low cost and durability of aluminium as the functional material in our pixel design, such polarization-sensitive encoding can realize a wide spectrum of applications in colour displays, data storage and anti-counterfeiting technologies. PMID:25369035

Goh, Xiao Ming; Zheng, Yihan; Tan, Shawn J; Zhang, Lei; Kumar, Karthik; Qiu, Cheng-Wei; Yang, Joel K W

2014-01-01

179

Galaxy Zoo: the dependence of morphology and colour on environment  

E-print Network

We analyse the relationships between galaxy morphology, colour, environment and stellar mass using data for over 100,000 objects from Galaxy Zoo, the largest sample of visually classified morphologies yet compiled. We conclusively show that colour and morphology fractions are very different functions of environment. Both are sensitive to stellar mass; however, at fixed stellar mass, while colour is also highly sensitive to environment, morphology displays much weaker environmental trends. Only a small part of both relations can be attributed to variation in the stellar mass function with environment. Galaxies with high stellar masses are mostly red, in all environments and irrespective of their morphology. Low stellar-mass galaxies are mostly blue in low-density environments, but mostly red in high-density environments, again irrespective of their morphology. The colour-density relation is primarily driven by variations in colour fractions at fixed morphology, in particular the fraction of spiral galaxies that have red colours, and especially at low stellar masses. We demonstrate that our red spirals primarily include galaxies with true spiral morphology. We clearly show there is an environmental dependence for colour beyond that for morphology. Before using the Galaxy Zoo morphologies to produce the above results, we first quantify a luminosity-, size- and redshift-dependent classification bias that affects this dataset, and probably most other studies of galaxy population morphology. A correction for this bias is derived and applied to produce a sample of galaxies with reliable morphological type likelihoods, on which we base our analysis.

Steven P. Bamford; Robert C. Nichol; Ivan K. Baldry; Kate Land; Chris J. Lintott; Kevin Schawinski; Anze Slosar; Alexander S. Szalay; Daniel Thomas; Mehri Torki; Dan Andreescu; Edward M. Edmondson; Christopher J. Miller; Phil Murray; M. Jordan Raddick; Jan Vandenberg

2008-05-16

180

How to Calculate Colourful Cross Sections Efficiently  

SciTech Connect

Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank

2008-09-03

181

Gastrointestinal tract size, total-tract digestibility, and rumen microflora in different dairy cow genotypes.  

PubMed

The superior milk production efficiency of Jersey (JE) and Jersey × Holstein-Friesian (JE × HF) cows compared with Holstein-Friesian (HF) has been widely published. The biological differences among dairy cow genotypes, which could contribute to the milk production efficiency differences, have not been as widely studied however. A series of component studies were conducted using cows sourced from a longer-term genotype comparison study (JE, JE × HF, and HF). The objectives were to (1) determine if differences exist among genotypes regarding gastrointestinal tract (GIT) weight, (2) assess and quantify whether the genotypes tested differ in their ability to digest perennial ryegrass, and (3) examine the relative abundance of specific rumen microbial populations potentially relating to feed digestibility. Over 3 yr, the GIT weight was obtained from 33 HF, 35 JE, and 27 JE × HF nonlactating cows postslaughter. During the dry period the cows were offered a perennial ryegrass silage diet at maintenance level. The unadjusted GIT weight was heavier for the HF than for JE and JE × HF. When expressed as a proportion of body weight (BW), JE and JE × HF had a heavier GIT weight than HF. In vivo digestibility was evaluated on 16 each of JE, JE × HF, and HF lactating dairy cows. Cows were individually stalled, allowing for the total collection of feces and were offered freshly cut grass twice daily. During this time, daily milk yield, BW, and dry matter intake (DMI) were greater for HF and JE × HF than for JE; milk fat and protein concentration ranked oppositely. Daily milk solids yield did not differ among the 3 genotypes. Intake capacity, expressed as DMI per BW, tended to be different among treatments, with JE having the greatest DMI per BW, HF the lowest, and JE × HF being intermediate. Production efficiency, expressed as milk solids per DMI, was higher for JE than HF and JE × HF. Digestive efficiency, expressed as digestibility of dry matter, organic matter, N, neutral detergent fiber, and acid detergent fiber, was higher for JE than HF. In grazing cows (n=15 per genotype) samples of rumen fluid, collected using a transesophageal sampling device, were analyzed to determine the relative abundance of rumen microbial populations of cellulolytic bacteria, protozoa, and fungi. These are critically important for fermentation of feed into short-chain fatty acids. A decrease was observed in the relative abundance of Ruminococcus flavefaciens in the JE rumen compared with HF and JE × HF. We can deduce from this study that the JE genotype has greater digestibility and a different rumen microbial population than HF. Jersey and JE × HF cows had a proportionally greater GIT weight than HF. These differences are likely to contribute to the production efficiency differences among genotypes previously reported. PMID:24704226

Beecher, M; Buckley, F; Waters, S M; Boland, T M; Enriquez-Hidalgo, D; Deighton, M H; O'Donovan, M; Lewis, E

2014-06-01

182

The acetabular component in total hip arthroplasty. Evaluation of different fixation principles.  

PubMed

Initial stability is necessary for permanent fixation of acetabular cups. Biologic reactions to submicron particles such as localized bone resorption may lead to implant failure. The aim of the study was to evaluate different fixation principles of acetabular components. Four randomized studies and one case-control study were performed to evaluate different bone cements, different cup designs, use of ceramic coating or not, different type of screws and the need of additional screw fixation or not. Radiostereometry (RSA) makes it possible to analyze small translations and rotations of implants with a high accuracy. This method is suitable for evaluation of early stability and was used in four of the studies. Clinical and radiological follow-up were performed regularly. The cements were tested in the laboratory. 30 patients (mean age 71 years, range: 63-76) received total hip arthroplasties and were randomised to fixation with Boneloc (14) or Palacos cum gentamicin (16) bone cement. The curing temperature was 23 degrees lower for the Boneloc cement but the tensile strength was reduced and the elastic modulus was lower compared to Palacos. The proximal cup migration was greater in the Boneloc group up to 12 months (p 0.04) and these cups migrated medially in contrast to a small lateral migration seen in the Palacos group (p 0.04). Radiolucencies were more pronounced in the Boneloc group at 12 months (p 0.04). 155 patients (171 hips, mean age 50 years, range: 24-64) received uncemented hip arthroplasties. 84 hips were randomised to the PCA and 87 to the Harris-Galante I designs. The 10-year survival rates were 85% for the PCA and 99% for the Harris-Galante I cups (revision as end-point). The wear and clinical results did not differ. 43 patients (mean age 60 years, range 44-68) received uncemented porous cups with a titanium mesh in pure titanium (Harris-Galante II) and were randomised to additional fixation with either biodegradable screws (23, poly-L-lactic acid, PLLA) or screws made of titanium alloy (20). Increased proximal and medial-lateral translations (p 0.02, 0.04) but less rotation around the longitudinal axis (p 0.04) were seen in the PLLA group up to 2 years. There were also more pronounced radiolucencies anteriorly in this group at 2 years. The clinical results did not differ. 23 uncemented porous cups (Harris-Galante II) with hydroxyapatite-tricalciumphosphate coating (HA/TCP) were pair-wise matched to uncoated cups. Up to 2 years, decreased rotations around the horizontal axis were recorded in the HA/TCP-coated cups. Central postoperative gaps were more frequently seen in the HA/TCP group (p < 0.01), but at 2 years radiolucencies were more pronounced in the uncoated group (p < 0.01). The wear and clinical results did not differ. 62 patients (64 hips, mean age 56 years, range: 32-75) were randomized to porous Trilogy cups with (30) and without (34) cluster holes for additional screw fixation. Up to 2 years there were no differences in migration, wear, radiographic findings or clinical results. In conclusion Boneloc cement was associated with poor fixation due to inferior mechanical properties. The PLLA screws did not provide sufficient stability. Unacceptably high failure rates were recorded for the PCA cup. HA/TCP coating improved the fixation and the interface of porous cups. HA/TCP coated porous cups can be fixed without adjunctive screw fixation. PMID:10572504

Thanner, J

1999-08-01

183

The Categorisation of Non-Categorical Colours: A Novel Paradigm in Colour Perception  

PubMed Central

In this paper, we investigate a new paradigm for studying the development of the colour ‘signal’ by having observers discriminate and categorize the same set of controlled and calibrated cardinal coloured stimuli. Notably, in both tasks, each observer was free to decide whether two pairs of colors were the same or belonged to the same category. The use of the same stimulus set for both tasks provides, we argue, an incremental behavioural measure of colour processing from detection through discrimination to categorisation. The measured data spaces are different for the two tasks, and furthermore the categorisation data is unique to each observer. In addition, we develop a model which assumes that the principal difference between the tasks is the degree of similarity between the stimuli which has different constraints for the categorisation task compared to the discrimination task. This approach not only makes sense of the current (and associated) data but links the processes of discrimination and categorisation in a novel way and, by implication, expands upon the previous research linking categorisation to other tasks not limited to colour perception. PMID:23536899

Cropper, Simon J.; Kvansakul, Jessica G. S.; Little, Daniel R.

2013-01-01

184

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

PubMed Central

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

2010-01-01

185

Plants and colour: Flowers and pollination  

Microsoft Academic Search

While there is a range of colours found in plants the predominant colour is green. Pigments in plants have several roles e.g. photosynthesis and signalling. If colour is to be used as a signal then it must stand out from green. However, one should be aware that there are also coloured compounds where we have not yet fully investigated the

Renee Miller; Simon J. Owens; Bjørn Rørslett

2011-01-01

186

Total haemoglobin mass, blood volume and morphological indices among athletes from different sport disciplines  

PubMed Central

Introduction Haemoglobin is a key determinant of maximal oxygen uptake. This study's objective was to assess total haemoglobin mass (tHb-mass), as well as blood volume and morphological indices in athletes training different sports disciplines. Material and methods This study was conducted on 176 endurance and non-endurance athletes (males and females). tHb-mass, blood volume (BV), plasma volume (PV), and red cell volume (RCV) were determined by optimized carbon monoxide rebreathing method. Haemoglobin concentration (Hb), haematocrit (Hct), red blood count (RBC) were also determined. Results In endurance sports, gender regardless, no significant differences in relative mean values of tHb-mass (12.8–13.1 g/kg – males; 10.4–10.6 g/kg – females), BV (90.8–94.0 ml/kg – males; 82.7–86.9 ml/kg – females), RCV (36.6–38.0 ml/kg – males; 31.1–31.5 ml/kg – females) or of PV in males (54.2–56.4 ml/kg) were observed. The above indices’ relative values, gender regardless, were significantly lower in judo (11.2 ±0.7 g/kg, 81.8 ±5.9 ml/kg, 48.6 ±4.5 ml/kg and 33.1 ±2.0 ml/kg – males; 9.3 ±0.7 g/kg, 74.3 ±5.6 ml/kg, 46.4 ±4.0 ml/kg and 27.9 ±2.1 ml/kg – females) compared to endurance sports (p < 0.001). No substantial differences were observed in morphological blood indices in males, whereas this differentiation was found between certain sports in female athletes. Conclusions The lack of differences in tHb-mass, BV, PV and RCV in endurance sports and presence of this differentiation between various sports shows that the types of training might affect levels of mentioned indices. Measurements of tHb-mass and BV parameters prove Hb, Hct and RBC to have limited value for haematological status evaluations. PMID:24273557

Sitkowski, Dariusz; Orysiak, Joanna; Pokrywka, Andrzej; Szygula, Zbigniew

2013-01-01

187

Colour appearance change of a large size display under various illumination conditions  

NASA Astrophysics Data System (ADS)

This paper describes an investigation into the effect of a wide range of surround conditions on the colour appearance of test colours on a 42" plasma display panel. Experiments were conducted using surrounds including dark, indoor and outdoor conditions. Additionally the stimulus size was changed by controlling the viewing distance. The viewing conditions studied were two bright, two average, two dim and two dark surrounds. Each of the test colours was assessed by 10 observers using a magnitude estimation method. These surrounds were divided into two categories. In the first category, the surround had no effect on the displayed colours, but observers could still sense the different brightness levels of the surround. In the second category, surround introduced flare to the displayed colours together. For the first category, little visual lightness difference was shown between bright and dark, and dim and dark surround, unlike the expectation that the perceived lightness contrast may increase as the surround becomes brighter. The lightness dependency of colourfulness, however, was found to change. For the second category, the visual colour appearance of the surround conditions was plotted against measured data, CIELAB L*, C* values, to try to understand the surround effect. As the surround became brighter, the perceived dynamic range of visual lightness decreased, and the perceived colourfulness increased, more obviously in high chroma colours. In the investigation of the change of stimulus size under different surround conditions, visual colour appearance was not affected by the stimulus sizes of 2 ° and 0.6 ° in the dark surround. However, the difference was found in the very dark colours with a dim surround. Finally, all of visual colour appearance data were used to test the performance of the colour appearance model CIECAM02. Minor modification was accomplished to improve the colourfulness predictor, especially for the black background.

Choi, Seo Young; Luo, Ming Ronnier; Pointer, Michael R.

2007-01-01

188

Coupling functions for NM total intensity and different multiplicities: Analytical approach  

NASA Astrophysics Data System (ADS)

Coupling functions for NM total intensity and different multiplicities play important role when we by observed data of cosmic ray (CR) variations on the ground based detectors (mostly neutron monitors and muon telescopes) tried to determine the primary variations of CR energy spectrum out of the Earth’s atmosphere and magnetosphere, into interplanetary space. This is especially important for forecasting expected radiation hazards from solar CR, because by determined primary solar CR energy spectrum in the interplanetary space it is possible to determine effective time of solar CR ejection into solar wind, source function and the diffusion coefficient of solar CR propagation in space in dependence of particle energy and distance from the Sun. Coupling functions are important also for investigations of Forbush effect and precursory effects for forecasting dangerous interplanetary shock waves. We check obtained results for coupling functions by latitude expedition experimental data. We found how coupling functions depend from the level of solar activity and pressure on the level of observations. Obtained results are presented in the analytical forms that are convenient to use for any NM at any place on the Earth.

Lev, Dorman

189

The variable colours of the fiddler crab Uca vomeris and their relation to background and predation.  

PubMed

Colour changes in fiddler crabs have long been noted, but a functional interpretation is still lacking. Here we report that neighbouring populations of Uca vomeris in Australia exhibit different degrees of carapace colours, which range from dull mottled to brilliant blue and white. We determined the spectral characteristics of the mud substratum and of the carapace colours of U. vomeris and found that the mottled colours of crabs are cryptic against this background, while display colours provide strong colour contrast for both birds and crabs, but luminance contrast only for a crab visual system. We tested whether crab populations may become cryptic under the influence of bird predation by counting birds overflying or feeding on differently coloured colonies. Colonies with cryptically coloured crabs indeed experience a much higher level of bird presence, compared to colourful colonies. We show in addition that colourful crab individuals subjected to dummy bird predation do change their body colouration over a matter of days. The crabs thus appear to modify their social signalling system depending on their assessment of predation risk. PMID:17023607

Hemmi, Jan M; Marshall, Justin; Pix, Waltraud; Vorobyev, Misha; Zeil, Jochen

2006-10-01

190

Melanin-based colour polymorphism responding to climate change.  

PubMed

Climate warming leads to a decrease in biodiversity. Organisms can deal with the new prevailing environmental conditions by one of two main routes, namely evolving new genetic adaptations or through phenotypic plasticity to modify behaviour and physiology. Melanin-based colouration has important functions in animals including a role in camouflage and thermoregulation, protection against UV-radiation and pathogens and, furthermore, genes involved in melanogenesis can pleiotropically regulate behaviour and physiology. In this article, I review the current evidence that differently coloured individuals are differentially sensitive to climate change. Predicting which of dark or pale colour variants (or morphs) will be more penalized by climate change will depend on the adaptive function of melanism in each species as well as how the degree of colouration covaries with behaviour and physiology. For instance, because climate change leads to a rise in temperature and UV-radiation and dark colouration plays a role in UV-protection, dark individuals may be less affected from global warming, if this phenomenon implies more solar radiation particularly in habitats of pale individuals. In contrast, as desertification increases, pale colouration may expand in those regions, whereas dark colourations may expand in regions where humidity is predicted to increase. Dark colouration may be also indirectly selected by climate warming because genes involved in the production of melanin pigments confer resistance to a number of stressful factors including those associated with climate warming. Furthermore, darker melanic individuals are commonly more aggressive than paler conspecifics, and hence they may better cope with competitive interactions due to invading species that expand their range in northern latitudes and at higher altitudes. To conclude, melanin may be a major component involved in adaptation to climate warming, and hence in animal populations melanin-based colouration is likely to change as an evolutionary or plastic response to climate warming. PMID:24700793

Roulin, Alexandre

2014-11-01

191

Floral scent emitted by white and coloured morphs in orchids.  

PubMed

Polymorphism of floral signals, such as colour and odour, is widespread in flowering plants and often considered to be adaptive, reflecting various pollinator preferences for particular floral traits. Several authors have recently hypothesized that particular associations exist between floral colour and scent, which would result from shared biochemistry between these two floral traits. In this study, we compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of three different orchid species, including two food-deceptive species (Orchis mascula and Orchis simia) and a food-rewarding species (Anacamptis coriophora fragrans). We found clear interspecific differences in floral odours. As expected from their pollination strategy, the two deceptive orchids showed high inter-individual variation of floral volatiles, whereas the food-rewarding A. c. fragrans showed low variation of floral scent. Floral volatiles did not differ overall between white- and coloured-flowered morphs in O. mascula and A. c. fragrans, while O. simia exhibited different volatile profiles between the two colour morphs. However, a detailed analysis restricted to benzenoid compounds (which are associated with the production of floral anthocyanin pigments) showed that white inflorescences emitted more volatiles of the shikimic pathway than coloured ones, both for O. mascula and O. simia. These results are consistent with the current hypothesis that shared biochemistry creates pleiotropic links between floral colour and scent. Whether intraspecific variation of floral signals actually affects pollinator attraction and influences the reproductive success of these orchids remains to be determined. PMID:24525191

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

2014-04-01

192

Development and Performance Characterization of Colour Star Trackers  

NASA Astrophysics Data System (ADS)

Star trackers provide an essential component to a satellite mission requiring high-precision and high-accuracy attitude measurements. A star tracker operates by taking pictures of the celestial sphere and attempting to identify the stars in the image using a combination of the geometric and brightness patterns. The star-positions in the image then determine the attitude of the sensor in the inertial frame. I propose extending the capability of star trackers by including the colour properties of the stars into the star identification process; hence, colour star tracking. Current generation star trackers exist in a variety of forms, with a variety of additional potential designs and operational algorithms proposed in the literature. However, they all share the common trait of using a combination of geometric and monochrome brightness derived patterns to identify stars. Including colour information with the geometric and brightness properties into the identification process represents a new branch in the field of star tracker design. The process of measuring colour also causes a reduction in the amount of light gathered by the sensor, decreasing the number of stars observed. The challenge in colour star tracking becomes establishing that the additional information provided by colour to star patterns is greater than the loss of observable stars due to the measurement process. While superficially brief, accomplishing it touches upon a wide range of topic areas. This includes most research developed for monochromatic star trackers including imaging hardware, optics, noise rejection, parameter estimation, signal detection, data mining, pattern matching, and astronomy. Additionally, using colour necessitates introducing the topics of stellar photometry, spectral filtering, and colour imaging. The approach to colour star tracker development, presented here, considers three aspects to the operation of the technology: colour measurement, star detection, and star pattern matching. In the measurement of colour analysis, a new set of estimation techniques are developed to estimate the colour and position of stars using colour-filter-array and trichroic prism cameras. Validation of the proposed techniques is achieved through a combination of laboratory and nigh-sky testing of hardware prototypes. The detection performance of the colour star tracker designs centres on a comparison with equivalent monochrome designs. By considering primitive detection algorithms, essentially raw thresholding, allows for a fair determination of the relative performance. Numerical simulations of potential designs examine the percentage of the celestial sphere where sufficient quantity of stars can be observed to yield an identification. Finally, extending the results of the detection analysis allows for a determination of the ambiguity within observed star scenes. While not explicitly pattern matching, this analysis establishes a baseline for the performance to be expected from practical pattern matching algorithms. Together, the combined results establish the overall expected increase in performance of colour star tracking over equivalent monochrome designs. A critical goal of any star tracker design is to maximize the region of sky where the star tracker can successfully return an attitude solution. Additionally, the reliability of achieving correct attitude solutions must also be a factor. The work presented demonstrates that, given the correct design circumstances, colour star trackers can supersede their monochrome counterparts in these two aspects. Specifically by resolving formerly ambiguous scenes and increasing the total number of scenes that can yield a solution. As a consequence, colour measurement should now become a viable and explicit consideration in future star tracker design processes.

McVittie, Geoffrey

193

Colouring as a special list-colouring problem with selected lists  

Microsoft Academic Search

Colouring of planar graphs can be treated as a special list-colouring problem with selected lists for near-triangulations. The new idea is to use sublists of a common list of four colours, to enforce a common colour in all lists, and to admit on the bounding cycle at most one vertex with a list of at least two colours. By these

Peter Dörre

194

Juvenile colour polymorphism in the red rock crab, Cancer productus: patterns, causes, and possible adaptive significance.  

PubMed

Juveniles of the common red rock crab of the Northeastern Pacific, Cancer productus, display a stunning diversity of colours and patterns, while adults all have the same drab colouration. Although this is widely known, key questions remain: (1) Does the frequency of different juvenile colours or patterns vary among collection sites or seasonally? (2) Does juvenile colour polymorphism reflect genetic heterogeneity or phenotypic plasticity in response to variable environmental conditions? (3) Do juveniles of different colours or patterns prefer substrata of different heterogeneity or brightness? We therefore: (i) described the variation in colour and pattern of juvenile C. productus; (ii) tested for associations between colour/pattern morphs and crab size, collection site, and season, in the field; (iii) conducted preliminary tests for habitat preferences (background colour, substratum type, light level) of different colour/pattern morphs in laboratory experiments, and (iv) tested the effect of diet (mussels versus shrimp) and feeding rate (high versus low) on juvenile colour/pattern. We describe 30 phenotypes that embrace a wide range of colour and pattern variants. The proportions of these phenotypes did not vary significantly among four collection sites, but they did vary significantly with season: over the summer and fall, juvenile colour and pattern variation was gradually replaced by the uniform adult colouration. The number of crabs displaying adult colouration also increased with crab size. Laboratory experiments suggest no significant preferences of different juvenile morphs for different backgrounds, substrata, or light levels. Diet (mussels versus shrimp) and feeding frequency had no effect on colour/pattern. Collectively, these results, although limited in scope, are not consistent with two likely hypotheses that could explain the extensive colour and pattern variation in juvenile C. productus: (i) selection for background matching by different cryptic forms and (ii) direct effects of diet or feeding rate on colour or pattern. Most probably, the large variety of different juvenile morphs is a result of frequency-dependent selection in which abundant variants are attacked disproportionately often and rarer forms are favoured. Juvenile colour polymorphism in C. productus may reduce the vulnerability to visual predators, impede the formation of a search image, and consequently decrease the risk of predation during the juvenile stages. PMID:20435453

Krause-Nehring, Jacqueline; Matthias Starck, J; Palmer, A Richard

2010-05-01

195

Thermodynamics of two-colour QCD  

NASA Astrophysics Data System (ADS)

We discuss the thermodynamics of two-colour QCD with four flavours of staggered quarks on 8 3 × 4 and 16 3 × 4 lattices. In our simulations we use the Naik action for the fermions and a (1,2) tree-level improved gauge action. We analyze the deconfinement and chiral phase transitions for four different quark masses (m=0.1,0.05,0.025,0.015). Contrary to three-colour QCD the peak in the Polyakov loop susceptibility decreases with decreasing quark mass. This reflects an early breaking of the string in the heavy quark potential, which we verify explicitly by calculating the heavy quark potential at finite temperature using Polyakov loop correlations.

Kaczmarek, O.; Karsch, F.; Laermann, E.

1999-03-01

196

Improper colouring of unit disk graphs  

Microsoft Academic Search

Motivated by a satellite communications problem, we consider a generalised colouring problem on unit disk graphs. A colouring is k-improper if no vertex receives the same colour as k+1 of its neighbours. The k-improper chromatic number k(G) the least number of colours needed in a k-improper colouring of a graph G. The main subject of this work is analysing the

Ross J. Kang; Jean-S ebastien Sereni

197

Effect of malva nut gum (purified and crude), sodium chloride and phosphate on cooking, texture, colour, rheology and microstructure of different chicken meat batters  

Microsoft Academic Search

1.?In the first experiment, the effect of adding purified malva nut gum (PMG) to comminuted poultry breast meat batters formulated with different contents of sodium chloride (NaCl; 10 to 30 g\\/kg) and tripolyphosphate (TPP; 0 and 5 g\\/kg) was studied.2.?Increasing salt (sodium chloride) content, along with the addition of 1 g\\/kg PMG, was beneficial in reducing cooking loss. At all

S. Barbut; P. Somboonpanyakul; M. Quinton; A. Smith

2009-01-01

198

The Influence of Colour on Memory Performance: A Review  

PubMed Central

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

Dzulkifli, Mariam Adawiah; Mustafar, Muhammad Faiz

2013-01-01

199

Applications of Colour Processing In Optical Inspection  

NASA Astrophysics Data System (ADS)

Humans are endowed with the facility to perceive colour. This not only provides an additional aesthetic dimension but also helps perform visual tasks efficiently. There are many occupations, including inspection, not open to those with defective colour vision. Todays machine vision systems are virtually all colour-blind. Yet there are applications where colour is intrinsic. Consider for example the inspection and grading of fruit, vegetables, biscuits and other food products. Consider also the widespread use of colour coding for wiring and components in the electrical and electronic industries. Automatic optical inspection of such things cannot be done without relating to colour. There are other applications where colour is not directly relevant but the additional information provided can help simplify and speed up the processing task. This paper reviews the nature of colour, relating the psychophysical aspects of colour perception and the physical properties of available sensors to the needs of an automatic inspection system. The theory of colour perception is based on the tri-stimulus theory which says that any colour may be matched using appropriate proportions of three primary colours. Although later experiments have suggested human colour perception is more complex, most electronic video sensors employ a three colour system. Usually the red, green and blue primary components are derived and may be used directly as sensory inputs to a vision system. However the primary representation of colour is not the most efficient means of encoding nor is it the most useful basis for interpretive processing. The R,G and B primary signals may be simply transformed into a new coordinate system where one of the axes represents true object colour or hue. Using this new colour space simplifies processing. These ideas are illustrated by an inspection example. The colour coded wires of a European power cable are identified to ensure that a power plug is safely wired. For this application a straightforward and reliable inspection system can only be produced using colour information.

Thomas, W. V.; Connolly, C.

1986-11-01

200

Exploring the benefit of synaesthetic colours: testing for "pop-out" in individuals with grapheme-colour synaesthesia.  

PubMed

In grapheme-colour synaesthesia, letters, numbers, and words elicit involuntary colour experiences. Recently, there has been much emphasis on individual differences and possible subcategories of synaesthetes with different underlying mechanisms. In particular, there are claims that for some, synaesthesia occurs prior to attention and awareness of the inducing stimulus. We first characterized our sample using two versions of the "Synaesthetic Congruency Task" to distinguish "projector" and "associator" synaesthetes who may differ in the extent to which their synaesthesia depends on attention and awareness. We then used a novel modification of the "Embedded Figures Task" that included a set-size manipulation to look for evidence of preattentive "pop-out" from synaesthetic colours, at both a group and an individual level. We replicate an advantage for synaesthetes over nonsynaesthetic controls on the Embedded Figures Task in accuracy, but find no support for pop-out of synaesthetic colours. We conclude that grapheme-colour synaesthetes are fundamentally similar in their visual processing to the general population, with the source of their unusual conscious colour experiences occurring late in the cognitive hierarchy. PMID:23768150

Rich, Anina N; Karstoft, Karen-Inge

2013-01-01

201

Colour pairs for constraining the age and metallicity of stellar populations  

NASA Astrophysics Data System (ADS)

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

Li, Zhongmu; Han, Zhanwen

2008-04-01

202

The colour of gender stereotyping.  

PubMed

Despite legislative attempts to eliminate gender stereotyping from society, the propensity to evaluate people on the basis of their sex remains a pernicious social problem. Noting the critical interplay between cultural and cognitive factors in the establishment of stereotypical beliefs, the current investigation explored the extent to which culturally transmitted colour-gender associations (i.e., pink is for girls, blue is for boys) set the stage for the automatic activation and expression of gender stereotypes. Across six experiments, the results demonstrated that (1) consumer choice for children's goods is dominated by gender-stereotyped colours (Experiment 1); (2) colour-based stereotypic associations guide young children's behaviour (Experiment 2); (3) colour-gender associations automatically activate associated stereotypes in adulthood (Experiments 3-5); and (4) colour-based stereotypic associations bias impressions of male and female targets (Experiment 6). These findings indicate that, despite prohibitions against stereotyping, seemingly innocuous societal practices may continue to promote this mode of thought. PMID:21752009

Cunningham, Sheila J; Macrae, C Neil

2011-08-01

203

Opening up a Colourful Cosmic Jewel Box  

NASA Astrophysics Data System (ADS)

The combination of images taken by three exceptional telescopes, the ESO Very Large Telescope on Cerro Paranal , the MPG/ESO 2.2-metre telescope at ESO's La Silla observatory and the NASA/ESA Hubble Space Telescope, has allowed the stunning Jewel Box star cluster to be seen in a whole new light. Star clusters are among the most visually alluring and astrophysically fascinating objects in the sky. One of the most spectacular nestles deep in the southern skies near the Southern Cross in the constellation of Crux. The Kappa Crucis Cluster, also known as NGC 4755 or simply the "Jewel Box" is just bright enough to be seen with the unaided eye. It was given its nickname by the English astronomer John Herschel in the 1830s because the striking colour contrasts of its pale blue and orange stars seen through a telescope reminded Herschel of a piece of exotic jewellery. Open clusters [1] such as NGC 4755 typically contain anything from a few to thousands of stars that are loosely bound together by gravity. Because the stars all formed together from the same cloud of gas and dust their ages and chemical makeup are similar, which makes them ideal laboratories for studying how stars evolve. The position of the cluster amongst the rich star fields and dust clouds of the southern Milky Way is shown in the very wide field view generated from the Digitized Sky Survey 2 data. This image also includes one of the stars of the Southern Cross as well as part of the huge dark cloud of the Coal Sack [2]. A new image taken with the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile shows the cluster and its rich surroundings in all their multicoloured glory. The large field of view of the WFI shows a vast number of stars. Many are located behind the dusty clouds of the Milky Way and therefore appear red [3]. The FORS1 instrument on the ESO Very Large Telescope (VLT) allows a much closer look at the cluster itself. The telescope's huge mirror and exquisite image quality have resulted in a brand-new, very sharp view despite a total exposure time of just 5 seconds. This new image is one of the best ever taken of this cluster from the ground. The Jewel Box may be visually colourful in images taken on Earth, but observing from space allows the NASA/ESA Hubble Space Telescope to capture light of shorter wavelengths than can not be seen by telescopes on the ground. This new Hubble image of the core of the cluster represents the first comprehensive far ultraviolet to near-infrared image of an open galactic cluster. It was created from images taken through seven filters, allowing viewers to see details never seen before. It was taken near the end of the long life of the Wide Field Planetary Camera 2 ? Hubble's workhorse camera up until the recent Servicing Mission, when it was removed and brought back to Earth. Several very bright, pale blue supergiant stars, a solitary ruby-red supergiant and a variety of other brilliantly coloured stars are visible in the Hubble image, as well as many much fainter ones. The intriguing colours of many of the stars result from their differing intensities at different ultraviolet wavelengths. The huge variety in brightness of the stars in the cluster exists because the brighter stars are 15 to 20 times the mass of the Sun, while the dimmest stars in the Hubble image are less than half the mass of the Sun. More massive stars shine much more brilliantly. They also age faster and make the transition to giant stars much more quickly than their faint, less-massive siblings. The Jewel Box cluster is about 6400 light-years away and is approximately 16 million years old. Notes [1] Open, or galactic, star clusters are not to be confused with globular clusters ? huge balls of tens of thousands of ancient stars in orbit around our galaxy and others. It seems that most stars, including our Sun, formed in open clusters. [2] The Coal Sack is a dark nebula in the Southern Hemisphere, near the Southern Cross, that can be seen with the unaided eye. A dark nebula is not the compl

2009-10-01

204

A novel framework for low-light colour image enhancement and denoising  

Microsoft Academic Search

This article describes a novel framework for low-light colour image enhancement and denoising. To avoid influences from different colour channels, noise reduction and brightness\\/contrast enhancement are performed in different colour spaces. In the HSI space, the Bilateral filter is used for illumination- and reflection-component separation, and is effective for edge-preservation, halo removal and noise suppression. Brightness\\/contrast are extrapolated by using

Wenshuai Yin; Xiangbo Lin; Yi Sun

2011-01-01

205

Pseudoaneurysm after total knee arthroplasty: a rare complication with different possible clinical presentations.  

PubMed

We report three cases of false aneurysm involving the popliteal artery or one of its branches following total knee replacement. Two of them developed after primary total knee arthroplasty (TKA) and the third one after a revision TKA. False aneurysm is a rare complication of TKA. The main symptom is generally a painful pulsatile mass which develops postoperatively but our cases occurred with three distinct clinical manifestations. Doppler ultrasonographic and angio-CT investigations were used to achieve the correct diagnosis. Two patients were treated by percutaneous embolization; the third patient required a mini-open surgery with an endovascular prosthesis. No complications were encountered. PMID:23547509

Boutchichi, Ali; Ciornohac, Jean; Daubresse, François

2013-02-01

206

Co-Housing Rodents with Different Coat Colours as a Simple, Non-Invasive Means of Individual Identification: Validating Mixed-Strain Housing for C57BL/6 and DBA/2 Mice  

PubMed Central

Standard practice typically requires the marking of laboratory mice so that they can be individually identified. However, many of the common methods compromise the welfare of the individuals being marked (as well as requiring time, effort, and/or resources on the part of researchers and technicians). Mixing strains of different colour within a cage would allow them to be readily visually identifiable, negating the need for more invasive marking techniques. Here we assess the impact that mixed strain housing has on the phenotypes of female C57BL/6 (black) and DBA/2 (brown) mice, and on the variability in the data obtained from them. Mice were housed in either mixed strain or single strain pairs for 19 weeks, and their phenotypes then assessed using 23 different behavioural, morphological, haematological and physiological measures widely used in research and/or important for assessing mouse welfare. No negative effects of mixed strain housing could be found on the phenotypes of either strain, including variables relevant to welfare. Differences and similarities between the two strains were almost all as expected from previously published studies, and none were affected by whether mice were housed in mixed- or single-strain pairs. Only one significant main effect of housing type was detected: mixed strain pairs had smaller red blood cell distribution widths, a measure suggesting better health (findings that now need replicating in case they were Type 1 errors resulting from our multiplicity of tests). Furthermore, mixed strain housing did not increase the variation in data obtained from the mice: the standard errors for all variables were essentially identical between the two housing conditions. Mixed strain housing also made animals very easy to distinguish while in the home cage. Female DBA/2 and C57BL/6 mice can thus be housed in mixed strain pairs for identification purposes, with no apparent negative effects on their welfare or the data they generate. This suggests that there is much value in exploring other combinations of strains. PMID:24204864

Walker, Michael; Fureix, Carole; Palme, Rupert; Mason, Georgia

2013-01-01

207

Ecological genomics in full colour.  

PubMed

Colour patterns in animals have long offered an opportunity to observe adaptive traits in natural populations. Colour plays myriad roles in interactions within and among species, from reproductive signalling to predator avoidance, leading to multiple targets of natural and sexual selection and opportunities for diversification. Understanding the genetic and developmental underpinnings of variation in colour promises a fuller understanding of these evolutionary processes, but the path to unravelling these connections can be arduous. The advent of genomic techniques suitable for nonmodel organisms is now beginning to light the way. Two new studies in this issue of Molecular Ecology use genomic sequencing of laboratory crosses to map colour traits in cichlid fishes, a remarkably diverse group in which coloration has played a major role in diversification. They illustrate how genomic approaches, specifically RAD sequencing, can rapidly identify both simple and more complex genetic variation underlying ecologically important traits. In the first, Henning et al. () detect a single locus that appears to control in a Mendelian fashion the presence of horizontal stripes, a trait that has evolved in numerous cichlid lineages. In the second, Albertson et al. () identify several genes and epistatic interactions affecting multiple colour traits, as well as a novel metric describing integration across colour traits. Albertson et al. () go further, by quantifying differential expression of parental alleles at a candidate locus and by relating differentiation among natural populations at mapped loci to trait divergence. Herein lies the promise of ecological genomics - efficiently integrating genetic mapping of phenotypes with population genomic data to both identify functional genes and unravel their evolutionary history. These studies offer guidance on how genomic techniques can be tailored to a research question or study system, and they also add to the growing body of empirical examples addressing basic questions about how ecologically important traits evolve in natural populations. PMID:25330852

Hohenlohe, Paul A

2014-11-01

208

Total dietary fibre content of some green and root vegetables obtained at different ethanol concentrations  

Microsoft Academic Search

The effect of reducing ethanol concentration for the precipitation of soluble dietary fibre in the Association of Official Analytical Chemists (AOAC, 1990, 1992, Official Methods of Analysis) enzymatic-gravimetric method 985.29 for total dietary fibre (TDF) in food was investigated. Alcohol concentration was decreased from 76% to 41% and 56% in determining TDF of raw collard and mustard greens, sweet potato

Aurea M. Almazan; Xiaohua Zhou

1995-01-01

209

Comparison of different analytical methods for assessing total antioxidant capacity of human serum  

Microsoft Academic Search

Three assays were compared for the determination of total antioxidant capacity in human serum: the oxygen radical absorbance capacity (ORAC) assay, the Randox Trolox-equivalent antioxidant capacity (Randox-TEAC) assay, and the ferric reducing ability (FRAP) assay. There was a weak but significant linear correlation between serum ORAC and serum FRAP. There was no correlation either between serum ORAC and serum TEAC

Guohua Cao; Ronald L. Prior

1998-01-01

210

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

PubMed

Variability in flower colour of animal-pollinated plants is common and caused, inter alia, by inter-individual differences in pigment concentrations. If and how pollinators, especially bees, respond to these small differences in pigment concentration is not known, but it is likely that flower colour variability impacts the choice behaviour of all flower visitors that exhibit innate and learned colour preferences. In behavioural experiments, we simulated varying pigment concentrations and studied its impact on the colour choices of bumblebees and honeybees. Individual bees were trained to artificial flowers having a specific concentration of a pigment, i.e. Acridine Orange or Aniline Blue, and then given the simultaneous choice between three test colours including the training colour, one colour of lower and one colour of higher pigment concentration. For each pigment, two set-ups were provided, covering the range of low to middle and the range of middle to high pigment concentrations. Despite the small bee-subjective perceptual contrasts between the tested stimuli and regardless of training towards medium concentrations, bees preferred neither the training stimuli nor the stimuli offering the highest pigment concentration but more often chose those stimuli offering the highest spectral purity and the highest chromatic contrast against the background. Overall, this study suggests that bees choose an intermediate pigment concentration due to its optimal conspicuousness. It is concluded that the spontaneous preferences of bees for flower colours of high spectral purity might exert selective pressure on the evolution of floral colours and of flower pigmentation. PMID:23722560

Papiorek, Sarah; Rohde, Katja; Lunau, Klaus

2013-07-01

211

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

NASA Astrophysics Data System (ADS)

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

Papiorek, Sarah; Rohde, Katja; Lunau, Klaus

2013-07-01

212

Beyond a Dichotomic Approach, the Case of Colour Phenomena  

ERIC Educational Resources Information Center

This research documents the aims and the impact of a teaching experiment concerning colour phenomena. This teaching experiment is designed in order to make students consider not only the spectral composition of light but also its intensity, and to consider the absorption of light by a pigment as relative, instead of as total or zero. Eight…

Viennot, L.; de Hosson, C.

2012-01-01

213

Rainbow Colouring of Split and Threshold Graphs  

E-print Network

A rainbow colouring of a connected graph is a colouring of the edges of the graph, such that every pair of vertices is connected by at least one path in which no two edges are coloured the same. Such a colouring using minimum possible number of colours is called an optimal rainbow colouring, and the minimum number of colours required is called the rainbow connection number of the graph. In this article, we show the following: 1. The problem of deciding whether a graph can be rainbow coloured using 3 colours remains NP-complete even when restricted to the class of split graphs. However, any split graph can be rainbow coloured in linear time using at most one more colour than the optimum. 2. For every integer k larger than 2, the problem of deciding whether a graph can be rainbow coloured using k colours remains NP-complete even when restricted to the class of chordal graphs. 3. For every positive integer k, threshold graphs with rainbow connection number k can be characterised based on their degree sequence al...

Chandran, L Sunil

2012-01-01

214

Correlation Between Chromophore Impurity Content and Fired Colour Data of Kaolin Clay  

NASA Astrophysics Data System (ADS)

Different kaolin clay specimen exhibit varying colours after firing depending upon the relative presence of different mineral impurities, physical state of mineral constituents etc. Spectrophotometers used for determining colour values generate many sets of colour data. Interpretation of such colour values is a subjective matter. Increase in darkness, yellowness etc as a consequence of increase in chromophore impurity content in kaolin clay have been shown. However, the inverse of above ie; gradual change in colour values along with gradual change in chromophore impurity content over a realistic range has not been studied. Whether the colour data of kaolin clay after firing can be taken up as a function of impurity content needs to be investigated. Thus, to identify the correlation between kaolin clay impurity content and it's fired colour data the present investigation examined the hypotheses i) The colour development after firing of kaolin clay is an indicator of chromophore impurity content present therein and ii) All the colour variables (L, a, b, ISO2470, redness) constituting a colour data set of pressed kaolin clay specimen after firing will vary in similar manner such that to represent variation in impurity content. The study indicated that the colour values obtained by spectrophotometry of clay specimens after firing represent the chromophore impurity present therein in a less reliable manner. To relatively estimate the quantity of chromophore impurity present in a clay sample from its fired colour, the sample should be mixed with 50% by weight of potash feldspar, pressed in to tablet suitable for colour measurement and fired at or above 1220°C to vitrify. After that the ‘L’, ‘a’ and ‘ISO2470’ values obtained truly represent the chromophore present therein.

Agrawal, Parvesh; Misra, S. N.; Sharma, T.

215

Interstitial pneumonitis following total body irradiation for bone marrow transplantation using two different dose rates  

SciTech Connect

A total of 22 patients with leukemia have undergone allogeneic bone marrow transplantation (BMT) by the Quebec Co-operative Group for Marrow Transplantation from 1980 to 1982. All patients received 900 cGy total body irradiation (TBI), in a single fraction, on the day preceding BMT. The first 11 patients were treated on a cobalt unit at a constant dose rate of 4.7 to 6.3 cGy/min. Six of these patients developed interstitial pneumonitis (IP). The clinical course of three patients, two with idiopathic and one with drug-induced pneumonitis, was mild and recovery was complete in all. The other three patients developed severe infectious IP and two died. The next 11 patients were treated with a sweeping beam technique on a 4 MV linear accelerator delivering a total tumor dose of 900 cGy at an average dose rate of 6.0 to 6.5 cGy/min but an instantaneous dose rate of 21.0 to 23.5 cGy/min. Eight patients developed severe IP. Five of these were idiopathic and four died. Three were infectious and all died. The fatality of interstitial pneumonitis appeared to be greater in the group treated with the sweeping beam technique.

Kim, T.H.; Rybka, W.B.; Lehnert, S.; Podgorsak, E.B.; Freeman, C.R.

1985-07-01

216

Assessment of Antioxidant Potential, Total Phenolics and Flavonoids of Different Solvent Fractions of Monotheca Buxifolia Fruit  

PubMed Central

Objectives This study was conducted to investigate the antioxidant potential of methanol extract and its derived fractions (hexane, ethyl acetate, butanol, and aqueous) of fruits of Monotheca buxifolia (Falc.) Dc., a locally used fruit in Pakistan. Methods Dried powder of the fruit of M. buxifolia was extracted with methanol and the resultant was fractionated with solvents having escalating polarity; n-hexane, chloroform, ethyl acetate, n-butanol and the residual soluble aqueous fraction. Total phenolic and total flavonoid contents were estimated for the methanol and various fractions. These fractions were also subjected to various in vitro assays to estimate the scavenging activity for 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), superoxide, hydroxyl, hydrogen peroxide and reductive ability for ferric ions and phosphomolybdate assay. Results The n-butanol, aqueous and methanol fractions possessed high amount of phenolics and flavonoids compared with other fractions, and subsequently showed a pronounced scavenging activity on DPPH, ABTS, superoxide, hydroxyl and hydrogen peroxide radicals and had a potent reductive ability on ferric ion and phosphomolybdate assay. There was a found significant correlation between total phenolic and flavonoid contents and EC50 of DPPH, superoxide, hydrogen peroxide radical and phosphomolybdate assays, whereas a nonsignificant correlation was found with the hydroxyl radical and ABTS radical assay. Conclusion M. buxifolia fruit can be used as natural antioxidant source to prevent damage associated with free radicals. PMID:24298440

Jan, Shumaila; Khan, Muhammad Rashid; Rashid, Umbreen; Bokhari, Jasia

2013-01-01

217

Colour distributions in E-S0 galaxies . IV. Colour data and dust in E's from Nieto's B, R frames  

NASA Astrophysics Data System (ADS)

The B-R colours distributions (with R in Cousins's system) have been measured in 44 E classified galaxies in the Local Supercluster, from pairs of frames collected by Nieto and co-workers in 1989-91. These are nearly all from the CFHT, and of sub-arsec resolution. Great attention has been given to the effects of unequal PSF's in the B and R frames upon colour distributions near centre; such effects are illustrated from model calculations and from pseudo-colours obtained from pairs of frames taken in the same band but with different seeing conditions. Appropriate corrections were systematically applied in order to derive central colours and inner gradients, although still affected by the limited resolution of the frames. The radial colour distributions have been measured in more detail than usual, considering separately the near major axis and near minor axis regions of the isophotal contours. Azimuthal colour distributions, in rings limited by selected isophotes, were also obtained. Dust ``patterns", i.e. patches, lanes, arcs, ..., have been detected and mapped from the colour distributions. An ad hoc dust pattern importance index (or DPII) in a scale of 0 to 3, has been introduced to qualify their size and contrast. We have tried to find evidence of a diffuse dust concentration towards the disk, if one is apparent. Positive results (noted by the dd symbol) have been obtained for disky E's, whenever the inclination of their disk to the line of sight is large enough, and eventually also in the small isolated disks sometimes present in both boxy and disky galaxies. The red central peak occurring in many E-galaxies might be the signature of a central concentration of dust, also in cases where this peak is isolated rather than embedded in some extensive colour pattern. The properties of the near centre colour profiles have been related to a classification of nuclear photometric profiles into ``flat topped" and ``sharply peaked" (equivalent to ``core-like" and ``power-law" in the terminology of te[Faber et al. 1997).]{fab97} The published here data include the following: . Short descriptions and codes for the characters of the B-R distribution of each object, and comparison to the results of recent surveys. . A table of the mean B-R at the centre and at two selected isophotes, a ``core colour gradient" and the usual logarithmic gradient. . Maps of near core B-R isochromes and B isophotes for comparison. Images of the B-R colour distribution are made available in electronic form. Based on observations collected at the Canada-France-Hawaii Telescope and at the Observatoire du Pic du Midi.

Michard, R.

1999-06-01

218

Interference colours of soap bubbles  

Microsoft Academic Search

In this article, we present a new versatile method for calculating the interference colour of any configuration of thin, optically isotropic, dielectric films. This method is free from common weakness of previous methods, namely the poor accuracy for large angles of incidence of light. This method gives full control over the accuracy and speed of computations, and allows for adjustments

Dariusz Jaszkowski; Janusz Rzeszut

2003-01-01

219

The Colour of Butterflies' Wings  

Microsoft Academic Search

IN making some experiments a short time ago, I came across a fact of which I was hitherto ignorant. I wished to test the effect of acid on the colours of the wings of a butterfly or moth, and with this view applied muriatic acid to a dried and set specimen of the Six-spotted Burnet [Zygæna filipendulæ). The red parts

F. E. v

1870-01-01

220

The colours of the sun.  

NASA Astrophysics Data System (ADS)

In this paper, arguments are developed for treating (R-I)C as the most important colour to be derived for the Sun. The solar value of (R-I)C is then found to be 0.335±0.002 mag. This result updates a counterpart given by Taylor in 1992.

Taylor, B. J.

221

Colour Parametrization in a Multiparametric Image Interface  

E-print Network

) and HSV (hue, saturation, lightness), are linked to human colour perception: the former to cone cell types is an image. It, too, uses colour to depict its appearance. Thus, the smallest elements of an image

Oldford, R.W.

222

Modelling the change in colour of broccoli and green beans during blanching  

Microsoft Academic Search

The green colour of vegetables changes considerably during heat treatments like blanching. Green beans from two different countries and growing seasons, and the stems and florets of broccoli were heat-treated from 40 up to 96°C. The colour was monitored with the CIE-Lab system. Expressing the green colour as ?a*\\/b* proved to considerably reduce the observed variance within measuring samples. It

L. M. M. Tijskens; E. P. H. M. Schijvens; E. S. A. Biekman

2001-01-01

223

CR 27 - day variations according to NM Mt. Hermon and other CR stations: effects in total intensity and different multiplicities  

NASA Astrophysics Data System (ADS)

After correction NM data on snow effect according to our work presented for Moscow COSPAR 40-th Assembly (Dorman et al. “Snow effect for total NM intensity and different multiplicities on Mt. Hermon during 1998 - 2014”) we determined CR 27-day variations according to NM Mt. Hermon in total neutron intensity and different multiplicities. Obtained results for total neutron intensity we compare with results on other CR stations in dependence of altitude and cut-off rigidity. Results for different multiplicities we use for estimation rigidity spectrum of the CR 27-day variations. We estimate also the long-term changes in CR 27-day variations and its connection with 27-day variations of solar activity.

Lev, Dorman; Zukerman, Igor; Pustilnik, Lev; Dai, Uri; Shternlib, Abracham; Shai Applbaum, David; Kazantsev, Vasilii; Kozliner, Lev; Ben Israel, Isaac

224

BOTANICAL BRIEFING Structural colour and iridescence in plants: the poorly studied relations of pigment colour  

Microsoft Academic Search

†Background Colour is a consequence of the optical properties of an object and the visual system of the animal perceiving it. Colour is produced through chemical and structural means, but structural colour has been relatively poorly studied in plants. †Scope This Botanical Briefing describes the mechanisms by which structures can produce colour. In plants, as in animals, the most common

Beverley J. Glover; Heather M. Whitney

225

The connotations of English colour terms: Colour-based X-phemisms  

Microsoft Academic Search

This paper investigates the connotations of English colour terms with particular attention to figurative uses of black, white, grey, brown, yellow, red, green, blue and a few miscellaneous colours. The connotations are judged on the basis of whether the phrases in which the colour terms occur are typically orthophemistic, euphemistic, or dysphemistic. All the colours surveyed have some, often many,

Keith Allan

2009-01-01

226

Accuracy of different sensors for the estimation of pollutant concentrations (total suspended solids, total and dissolved chemical oxygen demand) in wastewater and stormwater.  

PubMed

Many field investigations have used continuous sensors (turbidimeters and/or ultraviolet (UV)-visible spectrophotometers) to estimate with a short time step pollutant concentrations in sewer systems. Few, if any, publications compare the performance of various sensors for the same set of samples. Different surrogate sensors (turbidity sensors, UV-visible spectrophotometer, pH meter, conductivity meter and microwave sensor) were tested to link concentrations of total suspended solids (TSS), total and dissolved chemical oxygen demand (COD), and sensors' outputs. In the combined sewer at the inlet of a wastewater treatment plant, 94 samples were collected during dry weather, 44 samples were collected during wet weather, and 165 samples were collected under both dry and wet weather conditions. From these samples, triplicate standard laboratory analyses were performed and corresponding sensors outputs were recorded. Two outlier detection methods were developed, based, respectively, on the Mahalanobis and Euclidean distances. Several hundred regression models were tested, and the best ones (according to the root mean square error criterion) are presented in order of decreasing performance. No sensor appears as the best one for all three investigated pollutants. PMID:23863442

Lepot, Mathieu; Aubin, Jean-Baptiste; Bertrand-Krajewski, Jean-Luc

2013-01-01

227

Biological Components of Colour Preference in Infancy  

ERIC Educational Resources Information Center

Adult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S-(L+M) ("blue-yellow") and L-M ("red-green") cone-opponent contrast channels ( Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in…

Franklin, Anna; Bevis, Laura; Ling, Yazhu; Hurlbert, Anya

2010-01-01

228

Ultraviolet Colour Vision and Ornamentation in Bluethroats  

Microsoft Academic Search

Many birds see in the ultraviolet (300-400 nm), but there is limited evidence for colour communication (signalling by spectral shape independently of brightness) in this 'hidden' waveband. Such data are critical for the understanding of extravagant plumage colours, some of which show considerable UV reflectance. We investigated UV colour vision in female social responses to the male UV\\/violet ornament in

Staffan Andersson; Trond Amundsen

1997-01-01

229

Colour space models for soil science  

Microsoft Academic Search

Soil colour is an important soil property. It is frequently used by soil scientists for the identification and classification of soil. It is also used as an indicator of field soil physical, chemical and biological properties as well as of the occurrence of soil processes. Measurements of soil colour are commonly made using the Munsell soil colour charts. A number

R. A. Viscarra Rossel; B. Minasny; P. Roudier; A. B. McBratney

2006-01-01

230

Individual differences in physiologic measures are stable across repeated exposures to total sleep deprivation.  

PubMed

Some individuals show severe cognitive impairment when sleep deprived, whereas others are able to maintain a high level of performance. Such differences are stable and trait-like, but it is not clear whether these findings generalize to physiologic responses to sleep loss. Here, we analyzed individual differences in behavioral and physiologic measures in healthy ethnic-Chinese male volunteers (n = 12; aged 22-30 years) who were kept awake for at least 26 h in a controlled laboratory environment on two separate occasions. Every 2 h, sustained attention performance was assessed using a 10-min psychomotor vigilance task (PVT), and sleepiness was estimated objectively by determining percentage eyelid closure over the pupil over time (PERCLOS) and blink rate. Between-subject differences in heart rate and its variability, and electroencephalogram (EEG) spectral power were also analyzed during each PVT. To assess stability of individual differences, intraclass correlation coefficients (ICC) were determined using variance components analysis. Consistent with previous work, individual differences in PVT performance were reproducible across study visits, as were baseline sleep measures prior to sleep deprivation. In addition, stable individual differences were observed during sleep deprivation for PERCLOS, blink rate, heart rate and its variability, and EEG spectral power in the alpha frequency band, even after adjusting for baseline differences in these measures (range, ICC = 0.67-0.91). These findings establish that changes in ocular, ECG, and EEG signals are highly reproducible across a night of sleep deprivation, hence raising the possibility that, similar to behavioral measures, physiologic responses to sleep loss are trait-like. PMID:25263200

Chua, Eric Chern-Pin; Yeo, Sing-Chen; Lee, Ivan Tian-Guang; Tan, Luuan-Chin; Lau, Pauline; Tan, Sara S; Ho Mien, Ivan; Gooley, Joshua J

2014-09-01

231

Correlated evolution of colour pattern and body size in polymorphic pygmy grasshoppers, Tetrix undulata  

Microsoft Academic Search

Theory posits that selection on functionally interrelated characters will promote physical and genetic integration resulting in evolution of favourable trait-value combinations. The pygmy grasshopper Tetrix undulata (Orthoptera: Tetrigidae) displays a genetically encoded polymorphism for colour pattern. Colour morphs differ in several traits, including behaviours, thermal biology and body size. To examine if these size differences may reflect phenotypic plasticity of

J. Ahnesjo; A. Forsman

2003-01-01

232

Male choice for female colour morphs in Ischnura elegans (Odonata, Coenagrionidae): testing the hypotheses  

Microsoft Academic Search

The occurrence of different conspecific female colour morphs, with one of the morphs resembling the male, is supposed to have consequences for mate choice. There are two hypotheses linking mate choice and female colour polymorphism. First, males may mate predominantly with female morphs that differ from the male because they do not recognize androchrome females as females (male mimic hypothesis).

HANS VAN GOSSUM; ROBBY STOKS; ERIK MATTHYSEN; FAMKE VALCK; LUC DE BRUYN

1999-01-01

233

Evaluation of Fenton method and ozone-based processes for colour and organic matter removal from biologically pre-treated swine manure.  

PubMed

This work evaluates the efficiency of different advanced oxidation processes (Fenton method, O3, H2O2 and O3/H2O2) for removing total COD (TCOD) and colour from biologically pre-treated swine manure. The Fenton process with a dosage of 100mgL(-1) of Fe(2+) and 800mgL(-1) of H2O2 resulted in about 78% TCOD and 96% colour reductions at an initial pH=3 after a reaction time of 30min. Coagulation, rather than oxidation process, was identified as a crucial mechanism for removing pollutants. Otherwise, single ozonation achieved only 27-30% TCOD and 53-88% colour removals for ozone dosages ranging between 0.7 and 4.3gO3h(-1) at the original wastewater pH (pH=8.1) after 30min reaction time. The combined treatment with O3/H2O2 at pH=8.1 did not produce any significant TCOD or colour reduction improvement. Therefore, direct reactions with ozone rather than radical reactions were elucidated as the main removal mechanisms in the ozone-based processes. Finally, a rough estimation of the operational costs involved in each process was also performed to compare their economic feasibility. The findings suggested that the Fenton process was more suitable than ozonation for reducing TCOD and colour from the biologically pre-treated swine manure. PMID:25058844

Riaño, Berta; Coca, Mónica; García-González, Mari Cruz

2014-12-01

234

Determination of total flavonoids content in fresh Ginkgo biloba leaf with different colors using near infrared spectroscopy  

NASA Astrophysics Data System (ADS)

Total flavonoids content is often considered an important quality index of Ginkgo biloba leaf. The feasibility of using near infrared (NIR) spectra at the wavelength range of 10,000-4000 cm-1 for rapid and nondestructive determination of total flavonoids content in G. biloba leaf was investigated. 120 fresh G. biloba leaves in different colors (green, green-yellowish and yellow) were used to spectra acquisition and total flavonoids determination. Partial least squares (PLS), interval partial least squares (iPLS) and synergy interval partial least squares (SiPLS) were used to develop calibration models for total flavonoids content in two colors leaves (green-yellowish and yellow) and three colors leaves (green, green-yellowish and yellow), respectively. The level of total flavonoids content for green, green-yellowish and yellow leaves was in an increasing order. Two characteristic wavelength regions (5840-6090 cm-1 and 6620-6880 cm-1), which corresponded to the absorptions of two aromatic rings in basic flavonoid structure, were selected by SiPLS. The optimal SiPLS model for total flavonoids content in the two colors leaves (r2 = 0.82, RMSEP = 2.62 mg g-1) had better performance than PLS and iPLS models. It could be concluded that NIR spectroscopy has significant potential in the nondestructive determination of total flavonoids content in fresh G. biloba leaf.

Shi, Ji-yong; Zou, Xiao-bo; Zhao, Jie-wen; Mel, Holmes; Wang, Kai-liang; Wang, Xue; Chen, Hong

235

The fiddler crab Uca mjoebergi uses colour vision in mate choice  

PubMed Central

Although the role of colour in mate choice is well known, few tests of colour vision have been based on mating behaviour. Females of the fiddler crab Uca mjoebergi have recently been shown to use claw coloration to recognize conspecific males. In this study I demonstrate that the females use colour vision for this task; preferentially approaching yellow claws over grey claws regardless of their intensity while failing to discriminate between yellow claws differing in intensity. This is one of only a handful of studies confirming the involvement of colour vision in mate choice and the first conclusive evidence in fiddler crabs. PMID:17848366

Detto, Tanya

2007-01-01

236

Quantitative gait analysis after bilateral total knee arthroplasty with two different systems within each subject  

Microsoft Academic Search

The functional behavior of two kinematically different knee arthroplasty systems within each subject was studied by gait analysis (three-dimensional kinematics, kinetics, dynamic electromyography) in five elderly patients, 2 to 5 years after bilateral surgery. Clinical results were good, yet gait velocity was reduced (range, 0.57–1.1 m\\/s), with a shortened stride length and a decreased duration of single-limb stance in all

Inès A. Kramers-de Quervain; Edgar Stüssi; Roland Müller; Tomas Drobny; Urs Munzinger; Norbert Gschwend

1997-01-01

237

The effect of stress and stress hormones on dynamic colour-change in a sexually dichromatic Australian frog.  

PubMed

Rapid colour changes in vertebrates have fascinated biologists for centuries, herein we demonstrate dynamic colour change in an anuran amphibian, the stony creek frog (Litoria wilcoxii), which turns from brown to bright (lemon) yellow during amplexus. We show this by comparing the colour of baseline (unpaired males) and amplecting (paired) males. We also investigate the possible role of stress and stress hormones on this colour change. Frogs were subjected to four different levels of stressors (handling, toe-clipping, saline injection and adrenocorticotropic hormone [ACTH] injection) and the colour change was measured using digital photography. A comparison of baseline colour and stress hormone (corticosterone) levels was also conducted to give further insight to this topic. From the images, the Red Blue Green (RGB) colour values were calculated, and a principal components analysis (PCA) was used to create a single colour metric (the major axis) as an index of colour in the visible spectrum. A moderate stressor (toe-clipping) led to a significant change in colour (within 10 min) similar to that of amplecting males. Surprisingly, neither a mild stressor (handling and saline injection) nor the maximum stressor (handling and ACTH injection) led to a lightening response. This study confirms that the dynamic male colour change in this species in response to medium stressors adds new knowledge to the understanding of the functional mechanisms of dynamic colour change in amphibians. PMID:23507571

Kindermann, Christina; Narayan, Edward J; Wild, Francis; Wild, Clyde H; Hero, Jean-Marc

2013-06-01

238

Colour, pleasantness, and consumption behaviour within a meal.  

PubMed

It is often claimed that colour (e.g., in a meal) affects consumption behaviour. However, just how strong is the evidence in support of this claim, and what are the underlying mechanisms? It has been shown that not only the colour itself, but also the variety and the arrangement of the differently-coloured components in a meal influence consumers' ratings of the pleasantness of a meal (across time) and, to a certain extent, might even affect their consumption behaviour as well. Typically, eating the same food constantly or repeatedly leads to a decrease in its perceived pleasantness, which, as a consequence, might lead to decreased intake of that food. However, variation within a meal (in one or several sensory attributes, or holistically) has been shown to slow down this process. In this review, we first briefly summarize the literature on how general variety in a meal influences these variables and the major theories that have been put forward by researchers to explain them. We then go on to evaluate the evidence of these effects based mainly on the colour of the food explaining the different processes that might affect colour-based sensory-specific satiety and, in more detail, consumption behaviour. In addition, we also discuss the overlap in the definitions of these terms and provide additional hypothesis as to why, in some cases, the opposite pattern of results has been observed. PMID:24462488

Piqueras-Fiszman, Betina; Spence, Charles

2014-04-01

239

Galaxy Zoo: disentangling the environmental dependence of morphology and colour  

NASA Astrophysics Data System (ADS)

We analyse the environmental dependence of galaxy morphology and colour with two-point clustering statistics, using data from the Galaxy Zoo, the largest sample of visually classified morphologies yet compiled, extracted from the Sloan Digital Sky Survey. We present two-point correlation functions of spiral and early-type galaxies, and we quantify the correlation between morphology and environment with marked correlation functions. These yield clear and precise environmental trends across a wide range of scales, analogous to similar measurements with galaxy colours, indicating that the Galaxy Zoo classifications themselves are very precise. We measure morphology marked correlation functions at fixed colour and find that they are relatively weak, with the only residual correlation being that of red galaxies at small scales, indicating a morphology gradient within haloes for red galaxies. At fixed morphology, we find that the environmental dependence of colour remains strong, and these correlations remain for fixed morphology and luminosity. An implication of this is that much of the morphology-density relation is due to the relation between colour and density. Our results also have implications for galaxy evolution: the morphological transformation of galaxies is usually accompanied by a colour transformation, but not necessarily vice versa. A spiral galaxy may move on to the red sequence of the colour-magnitude diagram without quickly becoming an early type. We analyse the significant population of red spiral galaxies, and present evidence that they tend to be located in moderately dense environments and are often satellite galaxies in the outskirts of haloes. Finally, we combine our results to argue that central and satellite galaxies tend to follow different evolutionary paths. This publication has been made possible by the participation of more than 100000 volunteers in the Galaxy Zoo project. Their contributions are individually acknowledged at http://www.galaxyzoo.org/Volunteers.aspx E-mail: skibba@mpia.de

Skibba, Ramin A.; Bamford, Steven P.; Nichol, Robert C.; Lintott, Chris J.; Andreescu, Dan; Edmondson, Edward M.; Murray, Phil; Raddick, M. Jordan; Schawinski, Kevin; Slosar, Anže; Szalay, Alexander S.; Thomas, Daniel; Vandenberg, Jan

2009-10-01

240

[Inherited colour vision deficiencies--from Dalton to molecular genetics].  

PubMed

In recent years, great advances have been made in our understanding of the molecular basis of colour vision defects, as well as of the patterns of genetic variation in individuals with normal colour vision. Molecular genetic analyses have explained the diversity of types and degrees of severity in colour vision anomalies, their frequencies, pronounced individual variations in test results, etc. New techniques have even enabled the determination of John Dalton's real colour vision defect, 150 years after his death. Inherited colour vision deficiencies most often result from the mutations of genes that encode cone opsins. Cone opsin genes are linked to chromosomes 7 (the S or "blue" gene) and X (the L or "red" gene and the M or "green" gene). The L and M genes are located on the q arm of the X chromosome in a head-to-tail array, composed of 2 to 6 (typically 3) genes--a single L is followed by one or more M genes. Only the first two genes of the array are expressed and contribute to the colour vision phenotype. The high degree of homology (96%) between the L and M genes predisposes them to unequal recombination, leading to gene deletion or the formation of hybrid genes (comprising portions of both the L and M genes), explaining the majority of the common red-green colour vision deficiencies. The severity of any deficiency is influenced by the difference in spectral sensitivity between the opsins encoded by the first two genes of the array. A rare defect, S monochromacy, is caused either by the deletion of the regulatory region of the array or by mutations that inactivate the L and M genes. Most recent research concerns the molecular basis of complete achromatopsia, a rare disorder that involves the complete loss of all cone function. This is not caused by mutations in opsin genes, but in other genes that encode cone-specific proteins, e.g. channel proteins and transducin. PMID:16758855

Cvetkovi?, Dragana; Cvetkovi?, Dobrosav

2005-01-01

241

Galaxy Zoo: Disentangling the Environmental Dependence of Morphology and Colour  

E-print Network

We analyze the environmental dependence of galaxy morphology and colour with two-point clustering statistics, using data from the Galaxy Zoo, the largest sample of visually classified morphologies yet compiled, extracted from the Sloan Digital Sky Survey. We present two-point correlation functions of spiral and early-type galaxies, and we quantify the correlation between morphology and environment with marked correlation functions. These yield clear and precise environmental trends across a wide range of scales, analogous to similar measurements with galaxy colours, indicating that the Galaxy Zoo classifications themselves are very precise. We measure morphology marked correlation functions at fixed colour and find that they are relatively weak, with the only residual correlation being that of red galaxies at small scales, indicating a morphology gradient within haloes for red galaxies. At fixed morphology, we find that the environmental dependence of colour remains strong, and these correlations remain for fixed morphology \\textit{and} luminosity. An implication of this is that much of the morphology--density relation is due to the relation between colour and density. Our results also have implications for galaxy evolution: the morphological transformation of galaxies is usually accompanied by a colour transformation, but not necessarily vice versa. A spiral galaxy may move onto the red sequence of the colour-magnitude diagram without quickly becoming an early-type. We analyze the significant population of red spiral galaxies, and present evidence that they tend to be located in moderately dense environments and are often satellite galaxies in the outskirts of haloes. Finally, we combine our results to argue that central and satellite galaxies tend to follow different evolutionary paths.

Ramin A. Skibba; Steven P. Bamford; Robert C. Nichol; Chris J. Lintott; Dan Andreescu; Edward M. Edmondson; Phil Murray; M. Jordan Raddick; Kevin Schawinski; Anze Slosar; Alexander S. Szalay; Daniel Thomas; Jan Vandenberg

2008-11-24

242

Colour vision in diurnal and nocturnal hawkmoths.  

PubMed

Diurnal and nocturnal hawkmoths (Sphingidae, Lepidoptera) have three spectral types of receptor sensitive to ultraviolet, blue and green light. As avid flower visitors and pollinators, they use olfactory and visual cues to find and recognise flowers. Moths of the diurnal species Macroglossum stellatarum and the nocturnal species Deilephila elpenor, Hyles lineata and Hyles gallii use and learn the colour of flowers. Nocturnal species can discriminate flowers at starlight intensities when humans and honeybees are colour-blind. M. stellatarum can use achromatic, intensity-related cues if colour cues are absent, and this is probably also true for D. elpenor. Both species can recognise colours even under a changed illumination colour. PMID:21680465

Kelber, Almut; Balkenius, Anna; Warrant, Eric J

2003-08-01

243

The Effect of Different Doses of Aerobic Exercise Training on Total Bilirubin Levels  

PubMed Central

Low serum bilirubin levels have been associated with increased risk for cardiovascular disease, and recent data suggest that lower body fat and reductions in weight are associated with higher bilirubin levels. However, it is unknown if exercise training can increase bilirubin levels and whether a higher dose of exercise will further increase bilirubin levels compared to a lower dose. Purpose The primary aim of our current report is to examine whether exercise dose affects bilirubin levels in obese postmenopausal women from the Dose Response to Exercise in Women (DREW) trial. In addition, we evaluated whether changes in fitness, insulin sensitivity, and waist circumference associated with exercise training were associated with change in bilirubin levels. Methods Participants (n= 419) were randomized to the control group or 4, 8 and 12 kilocalories per kilogram per week (KKW) of exercise training at an intensity of 50% of aerobic capacity. Total bilirubin levels were evaluated at baseline and at follow-up. Results Exercise training significantly increased serum bilirubin levels only in the 12 KKW group (0.044 mg/dL, p=0.026) compared to control (0.004 mg/dL). Subgroup analyses showed that there was a significant increase in bilirubin levels in participants in the 12 KKW group (0.076 mg/dL) who were classified as insulin resistant (HOMA> 2.6), compared to insulin resistant control participants (0.018 mg/dL) (p=0.028). Conclusion Our findings suggest that high doses of exercise training are necessary to significantly increase bilirubin levels in previously sedentary postmenopausal women especially in individuals with impaired glucose metabolism. PMID:21900842

Swift, Damon L.; Johannsen, Neil M.; Earnest, Conrad P.; Blair, Steven N.; Church, Timothy S.

2011-01-01

244

Microbiology and Immunology Requirements 2013-14 Course requirements (Total of 8 different courses, not including Graduate Research)  

E-print Network

Microbiology and Immunology Requirements 2013-14 Course requirements (Total of 8 different courses Foundations in Experimental Biology 6 units MI 250* Frontiers in Microbiology & Immunology 1 unit MI 399 of Research 1 unit Spring MI 204 Innate Immunology 3 units MI 215 Principles of Biological Technologies 3

Sonnenburg, Justin L.

245

Microbiology and Immunology Requirements 2012-13 Course requirements (Total of 8 different courses, not including Research)  

E-print Network

Microbiology and Immunology Requirements 2012-13 Course requirements (Total of 8 different courses, not including Research) Aut: BIOS 200 The Nucleus (8 units) MI 250* Frontiers in Microbiology & Immunology (1 The Responsible Conduct of Research (1 unit) Spr: MI 204 Innate Immunology (3 units) MI 215 Principles

Sonnenburg, Justin L.

246

Salinity-imposed changes of some isozymes and total leaf protein expression in five mangroves from two different habitats  

Microsoft Academic Search

A comparative account of the polymorphic expression of two antioxidative enzymes (Peroxidase and Superoxide dismutase), two hydrolyzing enzymes (Esterase and Acid phosphatase) and total proteins was estimated both qualitatively and quantitatively from the leaves of five mangroves (Bruguiera gymnorrhiza, Excoecaria agallocha, Heritiera fomes, Phoenix paludosa and Xylocarpus granatum) from two different habitats (in situ habitat of Sundarbans and their replicas

Nirjhar Dasgupta; Paramita Nandy; Chandrakant Tiwari; Sauren Das

2010-01-01

247

Colour of sputum is a marker for bacterial colonisation in chronic obstructive pulmonary disease  

PubMed Central

Background Bacterial colonisation in chronic obstructive pulmonary disease (COPD) contributes to airway inflammation and modulates exacerbations. We assessed risk factors for bacterial colonisation in COPD. Methods Patients with stable COPD consecutively recruited over 1 year gave consent to provide a sputum sample for microbiologic analysis. Bronchial colonisation by potentially pathogenic microorganisms (PPMs) was defined as the isolation of PPMs at concentrations of ?102 colony-forming units (CFU)/mL on quantitative bacterial culture. Colonised patients were divided into high (>105 CFU/mL) or low (<105 CFU/mL) bacterial load. Results A total of 119 patients (92.5% men, mean age 68 years, mean forced expiratory volume in one second [FEV1] [% predicted] 46.4%) were evaluated. Bacterial colonisation was demonstrated in 58 (48.7%) patients. Patients with and without bacterial colonisation showed significant differences in smoking history, cough, dyspnoea, COPD exacerbations and hospitalisations in the previous year, and sputum colour. Thirty-six patients (62% of those colonised) had a high bacterial load. More than 80% of the sputum samples with a dark yellow or greenish colour yielded PPMs in culture. In contrast, only 5.9% of white and 44.7% of light yellow sputum samples were positive (P < 0.001). Multivariate analysis showed an increased degree of dyspnoea (odds ratio [OR] = 2.63, 95% confidence interval [CI] 1.53-5.09, P = 0.004) and a darker sputum colour (OR = 4.11, 95% CI 2.30-7.29, P < 0.001) as factors associated with the presence of PPMs in sputum. Conclusions Almost half of our population of ambulatory moderate to very severe COPD patients were colonised with PPMs. Patients colonised present more severe dyspnoea, and a darker colour of sputum allows identification of individuals more likely to be colonised. PMID:20470372

2010-01-01

248

Printing colour at the optical diffraction limit.  

PubMed

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. PMID:22886173

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

2012-09-01

249

Carotenoids need structural colours to shine  

PubMed Central

The bright colours of feathers are among the most striking displays in nature and are frequently used as sexual signals. Feathers can be coloured by pigments or by ordered tissue, and these mechanisms have traditionally been treated as distinct modes of display. Here we show that some yellow plumage colour is created both by reflection of light from white structural tissue and absorption of light by carotenoids. Thus, structural components of feathers contribute substantially to yellow ‘carotenoid’ displays, but the effect of variation in structural components on variation in colour displays is, to our knowledge, unstudied. The presence of structural colour in some carotenoid-based colour displays will have to be considered in studies of colour signalling. PMID:17148144

Shawkey, Matthew D; Hill, Geoffrey E

2005-01-01

250

Colourings and preservatives in food.  

PubMed

Colours and preservatives are only two of the many classes of additives in food but they are of interest because many reported cases of sensitivity involve these two groups of substances. Preservatives present the greatest potential health hazard being, by definition, biologically active. Colours and other additives are required to perform a technological function whilst remaining as biologically inert as possible. Food additives are controlled by the Food and Drugs Act 1955 on the basis of advice from the Food Advisory Committee (FAC). Lists of the permitted preservatives and colourings are available, together with details of restrictions on their uses; this information is continually being updated. Food labelling regulations mean that some information about additives can be determined from the labelling--but even if an additive is not listed on the package, one cannot always assume that it is not present in the product, since additives coming through in the original ingredients need not always be listed. Other exemptions also exist, so there can be no absolute certainty about the presence, or absence, of a specific additive. That information can only be obtained by contacting the manufacturer. PMID:6526689

Denner, W H

1984-12-01

251

Improvement of the colour discrimination ability of colour deficient people by modifying the parameters of the illumination  

Microsoft Academic Search

At the Department of Mechatronics, Optics and Engineering Informatics of BME the researches led by Dr. György Ábraham and Dr. Klára Wenzel have shown that defective color vision can be improved by specific spectral transmission color filters which modify the spectral characteristics of the lights reflected by different coloured surfaces so that the difference between colors will be increased. These

Ingrid Langer

2011-01-01

252

Worldwide distribution of Total Reflection X-ray Fluorescence instrumentation and its different fields of application: A survey  

NASA Astrophysics Data System (ADS)

A survey was carried out with users and manufacturers of Total Reflection X-ray Fluorescence instrumentation in order to demonstrate the worldwide distribution of TXRF equipment and the different fields of applications. In general, TXRF users come from universities and scientific institutes, from working places at synchrotron beam-lines, or laboratories in semiconductor fabs. TXRF instrumentation is distributed in more than 50 countries on six continents and is applied at about 200 institutes and laboratories. The number of running desktop instruments amounts to nearly 300 units. About 60 beamlines run working places dedicated to TXRF. About 300 floor-mounted instruments are estimated to be used in about 150 fabs of the semiconductor industry. In total, 13 different fields of applications could be registered statistically from three different aspects.

Klockenkämper, Reinhold; von Bohlen, Alex

2014-09-01

253

On the relationship between the phases of 27-day total ozone and solar activity indices in different latitudinal zones  

NASA Technical Reports Server (NTRS)

The dynamics of 27 day total ozone variations during and 11 year solar activity cycle at high and low latitudes was analyzed. The calculations were made using a specially worked out program permitting, besides the determination of the amplitudes and phases, the observation of the coherence of phases in any time interval. To characterize solar activity, solar radio-flux at 10.7 cm was used. The results of the calculation of total ozone phases difference and those of the index F(sub 10.7), as well as the amplitudes of the 27 day variations of these parameters are presented.

Ivanova, I. N.; Krivolutsky, A. A.; Kuznetsova, V. N.

1989-01-01

254

Colour appearance and compensation in the near periphery  

PubMed Central

The spectral sensitivity of the visual system varies markedly between the fovea and surrounding periphery owing in part to the rapid fall in macular pigment density with eccentricity. We examined how colour appearance changes between the fovea and near periphery (8°) by measuring achromatic loci and the loci of unique and binary hues. Chosen colours remained much more similar at the two locations than predicted by the change in spectral sensitivity. Compensation for white may reflect long-term gain changes within the cones that equate sensitivity for the local average stimulus in the fovea and periphery. However, adjusting only to the average stimulus cannot correct for all of the effects of a spectral sensitivity change, and predicts differences in colour percepts between the fovea and periphery that were not observed. The similarities in hue percepts at 0 and 8° thus suggest that additional processes help compensate colour appearance to maintain constancy in the near periphery. We model the results of previous studies to show that similar adjustments are implied by age-related changes in lens pigment, and to show that these adjustments are consistent with previous measurements of peripheral colour appearance based on hue cancellation. PMID:20147325

Webster, Michael A.; Halen, Kimberley; Meyers, Andrew J.; Winkler, Patricia; Werner, John S.

2010-01-01

255

An R2R3 MYB transcription factor determines red petal colour in an Actinidia (kiwifruit) hybrid population  

PubMed Central

Background Red colour in kiwifruit results from the presence of anthocyanin pigments. Their expression, however, is complex, and varies among genotypes, species, tissues and environments. An understanding of the biosynthesis, physiology and genetics of the anthocyanins involved, and the control of their expression in different tissues, is required. A complex, the MBW complex, consisting of R2R3-MYB and bHLH transcription factors together with a WD-repeat protein, activates anthocyanin 3-O-galactosyltransferase (F3GT1) to produce anthocyanins. We examined the expression and genetic control of anthocyanins in flowers of Actinidia hybrid families segregating for red and white petal colour. Results Four inter-related backcross families between Actinidia chinensis Planch. var. chinensis and Actinidia eriantha Benth. were identified that segregated 1:1 for red or white petal colour. Flower pigments consisted of five known anthocyanins (two delphinidin-based and three cyanidin-based) and three unknowns. Intensity and hue differed in red petals from pale pink to deep magenta, and while intensity of colour increased with total concentration of anthocyanin, no association was found between any particular anthocyanin data and hue. Real time qPCR demonstrated that an R2R3 MYB, MYB110a, was expressed at significant levels in red-petalled progeny, but not in individuals with white petals. A microsatellite marker was developed that identified alleles that segregated with red petal colour, but not with ovary, stamen filament, or fruit flesh colour in these families. The marker mapped to chromosome 10 in Actinidia. The white petal phenotype was complemented by syringing Agrobacterium tumefaciens carrying Actinidia 35S::MYB110a into the petal tissue. Red pigments developed in white petals both with, and without, co-transformation with Actinidia bHLH partners. MYB110a was shown to directly activate Actinidia F3GT1 in transient assays. Conclusions The transcription factor, MYB110a, regulates anthocyanin production in petals in this hybrid population, but not in other flower tissues or mature fruit. The identification of delphinidin-based anthocyanins in these flowers provides candidates for colour enhancement in novel fruits. PMID:23324587

2013-01-01

256

Addition Table of Colours: Additive and Subtractive Mixtures Described Using a Single Reasoning Model  

ERIC Educational Resources Information Center

Students' misconceptions concerning colour phenomena and the apparent complexity of the underlying concepts--due to the different domains of knowledge involved--make its teaching very difficult. We have developed and tested a teaching device, the addition table of colours (ATC), that encompasses additive and subtractive mixtures in a single…

Mota, A. R.; Lopes dos Santos, J. M. B.

2014-01-01

257

Training Grapheme-Colour Associations Produces a Synaesthetic Stroop Effect, but Not a Conditioned Synaesthetic Response  

ERIC Educational Resources Information Center

The goal of this study was to investigate whether behavioural and physiological consequences of synaesthesia can be elicited by training specific letter-colour associations. Towards this goal 20 non-synaesthetic individuals were trained for 10 min on 7 consecutive days to associate four different letters with four specific colours. After training,…

Meier, Beat; Rothen, Nicolas

2009-01-01

258

How Many Ways Can You Mix Colour? Young Children's Explorations of Mixed Reality Environments  

Microsoft Academic Search

How do we conceptualise and design mixed reality environments (MREs) to support creative play? Here we describe a first pass at a conceptual framework and use it do design a MRE for young children to explore in, focussing on the familiar activity of colour mixing. Different set-ups were provided, where paint or light colours could be mixed, using either physical

Silvia Gabrielli; Eric Harris; Yvonne Rogers; Mike Scaife; Hilary Smith

2001-01-01

259

Experimental manipulation reveals differential effects of colour pattern on survival in male and female pygmy grasshoppers  

Microsoft Academic Search

Populations of pygmy grasshoppers, Tetrix subulata, exhibit genetically coded discontinuous variation in colour pattern. To determine whether the dynamics of this polymorphism is likely to be affected by selective processes, rather than by stochastic events, we experimentally manipulated colour patterns of free- ranging grasshoppers and then calculated and controlled for differences in capture probabilities between categories of individuals before estimating

Appelqvist

1999-01-01

260

Published online 30 July 2002 The uses of colour vision: behavioural and  

E-print Network

that we learn from our experience of colour and greyscale images in photography, in the cinema and on television. However, this paper makes the case that the distinc- tiveness could arise naturally from signals or a by-product of our experience. In principle, colour images are qualitatively different from

Nottingham, University of

261

Genetics of male nuptial colour divergence between sympatric sister species of a Lake Victoria cichlid fish.  

PubMed

The hypothesis of sympatric speciation by sexual selection has been contentious. Several recent theoretical models of sympatric speciation by disruptive sexual selection were tailored to apply to African cichlids. Most of this work concludes that the genetic architecture of female preference and male trait is a key determinant of the likelihood of disruptive sexual selection to result in speciation. We investigated the genetic architecture controlling male nuptial colouration in a sympatric sibling species pair of cichlid fish from Lake Victoria, which differ conspicuously in male colouration and female mating preferences for these. We estimated that the difference between the species in male nuptial red colouration is controlled by a minimum number of two to four genes with significant epistasis and dominance effects. Yellow colouration appears to be controlled by one gene with complete dominance. The two colours appear to be epistatically linked. Knowledge on how male colouration segregates in hybrid generations and on the number of genes controlling differences between species can help us assess whether assumptions made in simulation models of sympatric speciation by sexual selection are realistic. In the particular case of the two sister species that we studied a small number of genes causing major differences in male colouration may have facilitated the divergence in male colouration associated with speciation. PMID:20345823

Magalhaes, I S; Seehausen, O

2010-05-01

262

Composition of pigments and colour changes in green table olives related to processing type.  

PubMed

Brownish colourations in Natural green table olives (non-treated with alkali) make this product less attractive to consumers than Spanish-style green table olives (treated with alkali), which develop a more appreciated bright golden-yellow colour. These colour differences were studied in relation to changes in the composition of chlorophyll and carotenoid pigments, as well as polyphenolic compounds and polyphenol oxidase enzyme (PPO) activity. Natural green olives showed a different chlorophyll profile than Spanish-style. However, all the chlorophyll pigments formed in both processing types were Mg-free derivatives (mostly pheophytins) with similar colourations, ranging from grey to green brownish. In the carotenoid fraction no appreciable differences were found between both processing types. The fruit's brownish colour was mainly due to polymeric substances with a size of >1000 daltons and polyphenolic nature, resulting from an enzymatic oxidation by PPO of the o-diphenolic compounds present in the fresh fruits. PMID:25053036

Ramírez, Eva; Gandul-Rojas, Beatriz; Romero, Concepción; Brenes, Manuel; Gallardo-Guerrero, Lourdes

2015-01-01

263

The original colours of fossil beetles  

PubMed Central

Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group. PMID:21957131

McNamara, Maria E.; Briggs, Derek E. G.; Orr, Patrick J.; Noh, Heeso; Cao, Hui

2012-01-01

264

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

PubMed Central

Background In many bird species colour traits influence social dominance and breeding success. In our study we first evaluated whether the colour of the basic plumage (tail feathers grown at the end of the breeding season), that provides an index of individual quality, influenced winter habitat use by yellow warblers. We then evaluated whether winter habitat use (inferred using ?13C and ?15N signatures of winter grown greater-coverts) influenced alternate plumage colouration, after controlling for individual quality using basic plumage colouration. Finally, we investigated whether basic and alternate plumage colouration influenced arrival dates, mate acquisition, breeding phenology and reproductive success of yellow warblers breeding in southern (Revelstoke, B.C.) and arctic (Inuvik, N.W.T.) Canada. Results The colour (chroma and hue) of tail feathers, grown on the breeding grounds, was not related to subsequent winter habitat use. Greater covert and tail feather colour (chroma and hue) were correlated, suggesting genetics and/or individual quality played a role in pigment deposition. After controlling for individual difference in tail colour, ?13C values did not explain any variation in greater covert colour, but birds with high ?15N signatures had greater coverts with higher chroma. Male arrival dates varied with tail chroma in Revelstoke and tail hue in Inuvik. Males that arrived early paired with older and/or more colourful mates that initiated clutches earlier, and at one site (Revelstoke) were more likely to fledge young. In addition, in Revelstoke (but not Inuvik) males with high tail hue also acquired more colourful mates. In contrast, after controlling for individual differences in tail colour, greater covert colour did not affect male arrival date, the quality of the mate obtained or reproductive success in either population. Conclusions Our results suggest that plumage colour effects on breeding phenology and mate acquisition result from differences in the intrinsic quality of individuals rather than a carry-over effect of winter habitat use. PMID:24886073

2014-01-01

265

Associations between Cigarette Smoking and Total Mortality Differ Depending on Serum Concentrations of Persistent Organic Pollutants among the Elderly  

PubMed Central

There are substantial variations of relative risks (RR) in smoking-related mortality by country and time. We hypothesized the RRs in smoking-related mortality might differ depending on serum concentrations of persistent organic pollutants (POPs). We evaluated the associations of cigarette smoking with total mortality in 610 elderly (aged ? 70 yr) (702 elderly for organochlorine pesticides [OCPs]) after stratification by serum concentration of POPs, in the National Health and Nutrition Examination Survey (NHANES) 1999-2004 followed through 2006. Summary measures of POPs subclasses showed significant or marginally significant interaction with cigarette smoking on the risk of total mortality. P values for interaction were 0.069 for polychlorinated dibenzo-p-dioxins (PCDDs), 0.008 for polychlorinated biphenyls (PCBs), and 0.024 for OCPs. The effect of smoking on total mortality showed different patterns according to the serum concentration of some POPs. Former or current smokers had 1.4 to 2.9 times higher mortality rates compared with never smokers among participants with higher serum concentrations of POPs (2nd or 3rd tertiles). However, when the level of PCBs or OCPs were low (1st tertile), there were little positive associations between smoking and mortality. Our study suggests that the background exposure to several POPs may be related to variability in smoking-related total mortality. PMID:23960436

Lee, Yu-Mi; Bae, Sang-Geun; Lee, Seon-Hwa; Jacobs, David R.

2013-01-01

266

Total Phenolic Contents and Antioxidant Activities of Different Extracts and Fractions from the Aerial Parts of Artemisia biennis Willd  

PubMed Central

Total phenolic contents (TPC) of five different extracts (petroleum ether, dichloromethane, ethyl acetate, ethanol and ethanol-water) of Artemisia biennis Willd were measured in this work. The antioxidant activity was investigated by three different methods: ?-carotene bleaching (BCB) test, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and ferrous ion chelating (FIC) assay. Among all the extracts analyzed, the hydroethanolic extract exhibited a significantly higher phenolic content and antioxidant activity than other samples. Vacuum liquid chromatography of this extract yielded seven fractions (A to G) which were subjected to all aforementioned experiments. The highest total phenolic content and free radical scavenging activites were present in the same sample (Fraction D) but the only statistically significant correlation between TPC and EC50 values was observed for BCB.

Hatami, Tayyebe; Emami, Sayyed Ahmad; Miraghaee, Sayyed Shahram; Mojarrab, Mahdi

2014-01-01

267

Original article Heritability of colour patterns in a closed population  

E-print Network

(Apis mellifera) queens, workers and drones, the offspring of the 10th generation of 20 queen families classifications were made for queens, workers and drones. The heritability of the colour of queens was 0.21 to 0.23; of workers 0.32, and drones 0.39, all significantly different from zero. It may be possible to breed honeybee

Paris-Sud XI, Université de

268

Flock formation and the role of plumage colouration in Ardeidae  

Microsoft Academic Search

It has been hypothesized that white plumage facilitates flock formation in Ardeidae. We conducted four ex- periments using decoys to test factors involved in attracting wading birds to a specific pond. The first three experi- ments tested the effects of plumage colouration, flock size, and species-specific decoys on flock formation. The fourth experiment examined intraspecific differences in flock choice between

M. Clay Green; Paul L. Leberg

2005-01-01

269

Fuzzy Homogeneity Measures for Path-based Colour Image Segmentation  

E-print Network

Fuzzy Homogeneity Measures for Path-based Colour Image Segmentation J. Chamorro-Martínez, D,daniel,belenps,elena}@decsai.ugr.es Abstract-- In this paper we study different measures of path homogeneity for fuzzy path-based image segmentation. We pro- vide fuzzy semantics for the concept of homogeneity in two steps: first, we introduce

Granada, Universidad de

270

Gloss and Colour of Dark Chocolate During Storage  

Microsoft Academic Search

The appearance of chocolate is greatly affected by bloom, which occurs during storage under unfavourable conditions. This phenomenon develops due to different causes, such as poor tempering, addition of incompatible fats, incorrect cooling methods, warm or fluctuating storage temperature, etc. The effect of storage temperature (4, 20, 25 and 30°C) on gloss (60 and 85° angle) and colour (CIE L

C. Pastor; J. Santamaría; A. Chiralt; J. M. Aguilera

2007-01-01

271

Separation of synthetic food colourants in the mixed micellar system  

Microsoft Academic Search

The paper presents a rapid method for the determination of commonly used synthetic food dyes by micellar electrokinetic capillary chromatography. Detection and separation conditions allowing complete resolution of 15 synthetic food colourants were investigated. The effect of different surfactants on the analytes mobility in relation to their structure was tested. After optimization procedure a dual micellar system was selected. All

Ma?gorzata Jaworska; Zofia Szuli?ska; Ma?gorzata Wilk; El?bieta Anuszewska

2005-01-01

272

"GenotypeColour™": colour visualisation of SNPs and CNVs  

PubMed Central

Background The volume of data available on genetic variations has increased considerably with the recent development of high-density, single-nucleotide polymorphism (SNP) arrays. Several software programs have been developed to assist researchers in the analysis of this huge amount of data, but few can rely upon a whole genome variability visualisation system that could help data interpretation. Results We have developed GenotypeColour™ as a rapid user-friendly tool able to upload, visualise and compare the huge amounts of data produced by Affymetrix Human Mapping GeneChips without losing the overall view of the data. Some features of GenotypeColour™ include visualising the entire genome variability in a single screenshot for one or more samples, the simultaneous display of the genotype and Copy Number state for thousands of SNPs, and the comparison of large amounts of samples by producing "consensus" images displaying regions of complete or partial identity. The software is also useful for genotype analysis of trios and to show regions of potential uniparental disomy (UPD). All information can then be exported in a tabular format for analysis with dedicated software. At present, the software can handle data from 10 K, 100 K, 250 K, 5.0 and 6.0 Affymetrix chips. Conclusion We have created a software that offers a new way of displaying and comparing SNP and CNV genomic data. The software is available free at and is especially useful for the analysis of multiple samples. PMID:19193232

Barlati, Sergio; Chiesa, Sergio; Magri, Chiara

2009-01-01

273

Variation of total FOS, total IOS, inulin and their related-metabolizing enzymes in burdock roots ( Arctium lappa L.) stored under different temperatures  

Microsoft Academic Search

Burdock roots were stored for six weeks at three temperatures, 0, 15 and 20°C, and activity of sucrose hydrolase (SH), 1-kestose hydrolase (1-KH), inulin hydrolase (InH), sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan:fructan 1-fructoslytransferase (1-FFT) were assessed. Simultaneously, total fructooligosaccharides (FOS), total inulooligosaccharides (IOS) and inulin were also assessed during storage. During storage, SH showed an irregular variation at 15 and 20°C,

Y. Ishiguro; S. Onodera; N. Benkeblia; N. Shiomi

2010-01-01

274

AFLP genome scans suggest divergent selection on colour patterning in allopatric colour morphs of a cichlid fish.  

PubMed

Genome scan-based tests for selection are directly applicable to natural populations to study the genetic and evolutionary mechanisms behind phenotypic differentiation. We conducted AFLP genome scans in three distinct geographic colour morphs of the cichlid fish Tropheus moorii to assess whether the extant, allopatric colour pattern differentiation can be explained by drift and to identify markers mapping to genomic regions possibly involved in colour patterning. The tested morphs occupy adjacent shore sections in southern Lake Tanganyika and are separated from each other by major habitat barriers. The genome scans revealed significant genetic structure between morphs, but a very low proportion of loci fixed for alternative AFLP alleles in different morphs. This high level of polymorphism within morphs suggested that colour pattern differentiation did not result exclusively from neutral processes. Outlier detection methods identified six loci with excess differentiation in the comparison between a bluish and a yellow-blotch morph and five different outlier loci in comparisons of each of these morphs with a red morph. As population expansions and the genetic structure of Tropheus make the outlier approach prone to false-positive signals of selection, we examined the correlation between outlier locus alleles and colour phenotypes in a genetic and phenotypic cline between two morphs. Distributions of allele frequencies at one outlier locus were indeed consistent with linkage to a colour locus. Despite the challenges posed by population structure and demography, our results encourage the cautious application of genome scans to studies of divergent selection in subdivided and recently expanded populations. PMID:22625655

Mattersdorfer, Karin; Koblmüller, Stephan; Sefc, Kristina M

2012-07-01

275

Adapted list colouring of planar graphs  

Microsoft Academic Search

Given a (possibly improper) edge-colouring F of a graph G, a vertex colour- ing of G is adapted to F if no colour appears at the same time on an edge and on its two endpoints. If for some integer k, a graph G is such that given any list assignment L to the vertices of G, with jL(v)j ‚

Louis Esperet; Mickael Montassiery Xuding Zhuz

276

Colour vision and response bias in a coral reef fish.  

PubMed

Animals use coloured signals for a variety of communication purposes, including to attract potential mates, recognize individuals, defend territories and warn predators of secondary defences (aposematism). To understand the mechanisms that drive the evolution and design of such visual signals, it is important to understand the visual systems and potential response biases of signal receivers. Here, we provide raw data on the spectral capabilities of a coral reef fish, the Picasso triggerfish Rhinecanthus aculeatus, which is potentially trichromatic with three cone sensitivities of 413 nm (single cone), 480 nm (double cone, medium sensitivity) and 528 nm (double cone, long sensitivity), and a rod sensitivity of 498 nm. The ocular media have a 50% transmission cut off at 405 nm. Behavioural experiments confirmed colour vision over their spectral range; triggerfish were significantly more likely to choose coloured stimuli over grey distractors, irrespective of luminance. We then examined whether response biases existed towards coloured and patterned stimuli to provide insight into how visual signals - in particular, aposematic colouration - may evolve. Triggerfish showed a preferential foraging response bias to red and green stimuli, in contrast to blue and yellow, irrespective of pattern. There was no response bias to patterned over monochromatic non-patterned stimuli. A foraging response bias towards red in fish differs from that of avian predators, who often avoid red food items. Red is frequently associated with warning colouration in terrestrial environments (ladybirds, snakes, frogs), whilst blue is used in aquatic environments (blue-ringed octopus, nudibranchs); whether the design of warning (aposematic) displays is a cause or consequence of response biases is unclear. PMID:23580729

Cheney, Karen L; Newport, Cait; McClure, Eva C; Marshall, N Justin

2013-08-01

277

Myopia and iris colour: a possible connection?  

PubMed

Myopia is a common ocular disease in the world. Its prevalence has increased rapidly worldwide, especially in some East-Asian countries. Genetic factors and environmental factors both affect myopia's onset and its progress. Iris colour is an important characteristic of a person. It is a possible risk factor for myopia by affecting the amount and the colour of light entering eyes. The study of iris colour may contribute to the understanding of myopia mechanism and provide good suggestive evidence for studies on other eye diseases. In this article, the possible connection between myopia and iris colour is proposed. Approaches to dissect any link are suggested. PMID:22465466

Meng, Weihua; Butterworth, Jacqueline; Calvas, Patrick; Malecaze, Francois

2012-06-01

278

Quantitative Monitoring for Enhanced Geothermal Systems Using Double-Difference Waveform Inversion with Spatially-Variant Total-Variation Regularization  

SciTech Connect

Double-difference waveform inversion is a promising tool for quantitative monitoring for enhanced geothermal systems (EGS). The method uses time-lapse seismic data to jointly inverts for reservoir changes. Due to the ill-posedness of waveform inversion, it is a great challenge to obtain reservoir changes accurately and efficiently, particularly when using timelapse seismic reflection data. To improve reconstruction, we develop a spatially-variant total-variation regularization scheme into double-difference waveform inversion to improve the inversion accuracy and robustness. The new regularization scheme employs different regularization parameters in different regions of the model to obtain an optimal regularization in each area. We compare the results obtained using a spatially-variant parameter with those obtained using a constant regularization parameter. Utilizing a spatially-variant regularization scheme, the target monitoring regions are well reconstructed and the image noise is significantly reduced outside the monitoring regions. Our numerical examples demonstrate that the spatially-variant total-variation regularization scheme provides the flexibility to regularize local regions based on the a priori spatial information without increasing computational costs and the computer memory requirement.

Lin, Youzuo [Los Alamos National Laboratory; Huang, Lianjie [Los Alamos National Laboratory; Zhang, Zhigang [Los Alamos National Laboratory

2011-01-01

279

An attempt to determine the colour of the solar corona during the solar eclipse of 2001 June 21 (preliminary results)  

NASA Astrophysics Data System (ADS)

An attempt to determine the colour of the solar corona during the total solar eclipse of June 21, 2001 using the set of colour filters, telescope of 300 mm and a CCD camera is described. The scattered light both in the telescope and in the CCD camera is a major obstacle to using this method in the future.

Luká?, B.; Minarovjech, M.; Rybanský, M.

2002-12-01

280

Feature Extraction and Simplification from colour images based on Colour Image Segmentation and Skeletonization  

E-print Network

application for completely automated or semi-automated processing of (satellite) imagery and scanned maps, as well as heating or pollution monitoring and dense forest mapping among others. Keywords: colour imageFeature Extraction and Simplification from colour images based on Colour Image Segmentation

281

Total and Partial Fragmentation Cross-Section of 500 MeV/nucleon Carbon Ions on Different Target Materials  

E-print Network

By using an experimental setup based on thin and thick double-sided microstrip silicon detectors, it has been possible to identify the fragmentation products due to the interaction of very high energy primary ions on different targets. Here we report total and partial cross-sections measured at GSI (Gesellschaft fur Schwerionenforschung), Darmstadt, for 500 MeV/n energy $^{12}C$ beam incident on water (in flasks), polyethylene, lucite, silicon carbide, graphite, aluminium, copper, iron, tin, tantalum and lead targets. The results are compared to the predictions of GEANT4 (v4.9.4) and FLUKA (v11.2) Monte Carlo simulation programs.

Alpat, Behcet; Blasko, Sandor; Caraffini, Diego; Di Capua, Francesco; Postolache, Vasile; Saltanocchi, Giorgio; Menichelli, Mauro; Desorgher, Laurent; Durante, Marco; Pleskac, Radek; La Tessa, Chiara

2014-01-01

282

Total and Partial Fragmentation Cross-Section of 500 MeV/nucleon Carbon Ions on Different Target Materials  

E-print Network

By using an experimental setup based on thin and thick double-sided microstrip silicon detectors, it has been possible to identify the fragmentation products due to the interaction of very high energy primary ions on different targets. Here we report total and partial cross-sections measured at GSI (Gesellschaft fur Schwerionenforschung), Darmstadt, for 500 MeV/n energy $^{12}C$ beam incident on water (in flasks), polyethylene, lucite, silicon carbide, graphite, aluminium, copper, iron, tin, tantalum and lead targets. The results are compared to the predictions of GEANT4 (v4.9.4) and FLUKA (v11.2) Monte Carlo simulation programs.

Behcet Alpat; Ercan Pilicer; Sandor Blasko; Diego Caraffini; Francesco Di Capua; Vasile Postolache; Giorgio Saltanocchi; Mauro Menichelli; Laurent Desorgher; Marco Durante; Radek Pleskac; Chiara La Tessa

2014-01-20

283

Illumination preference, illumination constancy and colour discrimination by bumblebees in an environment with patchy light.  

PubMed

Patchy illumination presents foraging animals with a challenge, as the targets being sought may appear to vary in colour depending on the illumination, compromising target identification. We sought to explore how the bumblebee Bombus terrestris copes with tasks involving flower colour discrimination under patchy illumination. Light patches varied between unobscured daylight and leaf-shade, as a bee might encounter in and around woodland. Using a flight arena and coloured filters, as well as one or two different colours of artificial flower, we quantified how bees chose to forage when presented with foraging tasks under patchy illumination. Bees were better at discriminating a pair of similar colours under simulated unobscured daylight illumination than when foraging under leaf-shade illumination. Accordingly, we found that bees with prior experience of simulated daylight but not leaf-shade illumination initially preferred to forage in simulated daylight when all artificial flowers contained rewards as well as when only one colour was rewarding, whereas bees with prior experience of both illuminants did not exhibit this preference. Bees also switched between illuminants less than expected by chance. This means that bees prefer illumination conditions with which they are familiar, and in which rewarding flower colours are easily distinguishable from unrewarding ones. Under patchy illumination, colour discrimination performance was substantially poorer than in homogenous light. The bees' abilities at coping with patchy light may therefore impact on foraging behaviour in the wild, particularly in woodlands, where illumination can change over short spatial scales. PMID:22675177

Arnold, Sarah E J; Chittka, Lars

2012-07-01

284

Dynamic application of digital image and colour processing in characterizing flame radiation features  

NASA Astrophysics Data System (ADS)

In this work, the experimental investigation of the dynamic flame properties of flame flickering and equivalence ratio sensing of a combustion process was done. In particular, the time-varied flame properties were examined using a novel digital image and colour processing methodology. This technique makes use of the observed correlation between a digital image colour signal and physical flame radiation characteristics in the visible wavelength domain. Aspects of RGB and HSV colour modelling principles were applied to show that the addition of colour identification in the image processing of high-speed flame image data could yield three useful parameters which are related to the dynamic behaviour of different flame emanating components. First, the validity of the colour identities for tracking the yellowish-red diffusion and greenish-blue premixed flame colourations were examined by comparing their respective flickering frequency profiles. Then, the usefulness of the extracted Rdiffusion, Gpremixed and Bpremixed colour signals to abstractly represent the behaviour of soot, C2* and CH* emission characteristics in a dynamic flame transition from diffusion to stoichiometric premixed condition was demonstrated. In particular, the colour signal ratio Bpremixed/Gpremixed was correlated to exemplify the approximate time-varied state of the equivalence ratio from the imaged combustion phenomenon.

Huang, Hua Wei; Zhang, Yang

2010-08-01

285

Filling schemes at submicron scale: Development of submicron sized plasmonic colour filters  

NASA Astrophysics Data System (ADS)

The pixel size imposes a fundamental limit on the amount of information that can be displayed or recorded on a sensor. Thus, there is strong motivation to reduce the pixel size down to the nanometre scale. Nanometre colour pixels cannot be fabricated by simply downscaling current pixels due to colour cross talk and diffraction caused by dyes or pigments used as colour filters. Colour filters based on plasmonic effects can overcome these difficulties. Although different plasmonic colour filters have been demonstrated at the micron scale, there have been no attempts so far to reduce the filter size to the submicron scale. Here, we present for the first time a submicron plasmonic colour filter design together with a new challenge - pixel boundary errors at the submicron scale. We present simple but powerful filling schemes to produce submicron colour filters, which are free from pixel boundary errors and colour cross- talk, are polarization independent and angle insensitive, and based on LCD compatible aluminium technology. These results lay the basis for the development of submicron pixels in displays, RGB-spatial light modulators, liquid crystal over silicon, Google glasses and pico-projectors.

Rajasekharan, Ranjith; Balaur, Eugeniu; Minovich, Alexander; Collins, Sean; James, Timothy D.; Djalalian-Assl, Amir; Ganesan, Kumaravelu; Tomljenovic-Hanic, Snjezana; Kandasamy, Sasikaran; Skafidas, Efstratios; Neshev, Dragomir N.; Mulvaney, Paul; Roberts, Ann; Prawer, Steven

2014-09-01

286

Filling schemes at submicron scale: Development of submicron sized plasmonic colour filters  

PubMed Central

The pixel size imposes a fundamental limit on the amount of information that can be displayed or recorded on a sensor. Thus, there is strong motivation to reduce the pixel size down to the nanometre scale. Nanometre colour pixels cannot be fabricated by simply downscaling current pixels due to colour cross talk and diffraction caused by dyes or pigments used as colour filters. Colour filters based on plasmonic effects can overcome these difficulties. Although different plasmonic colour filters have been demonstrated at the micron scale, there have been no attempts so far to reduce the filter size to the submicron scale. Here, we present for the first time a submicron plasmonic colour filter design together with a new challenge - pixel boundary errors at the submicron scale. We present simple but powerful filling schemes to produce submicron colour filters, which are free from pixel boundary errors and colour cross- talk, are polarization independent and angle insensitive, and based on LCD compatible aluminium technology. These results lay the basis for the development of submicron pixels in displays, RGB-spatial light modulators, liquid crystal over silicon, Google glasses and pico-projectors. PMID:25242695

Rajasekharan, Ranjith; Balaur, Eugeniu; Minovich, Alexander; Collins, Sean; James, Timothy D.; Djalalian-Assl, Amir; Ganesan, Kumaravelu; Tomljenovic-Hanic, Snjezana; Kandasamy, Sasikaran; Skafidas, Efstratios; Neshev, Dragomir N.; Mulvaney, Paul; Roberts, Ann; Prawer, Steven

2014-01-01

287

Fire severity effects on ash extractable Total Phosphorous  

NASA Astrophysics Data System (ADS)

Phosphorous (P) is a crucial element to plant nutrition and limits vegetal production. The amounts of P in soil are lower and great part of this nutrient is absorbed or precipitated. It is well known that fire has important implications on P cycle, that can be lost throughout volatilization, evacuated with the smoke, but also more available to transport after organic matter mineralization imposed by the fire. The release of P depends on ash pH and their chemical and physical characteristics. Fire temperatures impose different severities, according to the specie affected and contact time. Fire severity is often evaluated by ash colour and this is a low-cost and excellent methodology to assess the fire effects on ecosystems. The aim of this work is study the ash properties physical and chemical properties on ash extractable Total Phosphorous (TP), collected in three wildfires, occured in Portugal, (named, (1) Quinta do Conde, (2) Quinta da Areia and (3) Casal do Sapo) composed mainly by Quercus suber and Pinus pinaster trees. The ash colour was assessed using the Munsell color chart. From all three plots we analyzed a total of 102 ash samples and we identified 5 different ash colours, ordered in an increasing order of severity, Very Dark Brown, Black, Dark Grey, Very Dark Grey and Light Grey. In order to observe significant differences between extractable TP and ash colours, we applied an ANOVA One Way test, and considered the differences significant at a p<0.05. The results showed that significant differences in the extractable TP among the different ash colours. Hence, to identify specific differences between each ash colour, we applied a post-hoc Fisher LSD test, significant at a p<0.05. The results obtained showed significant differences between the extractable TP from Very dark Brown and Black ash, produced at lower severities, in relation to Dark Grey, Very Dark Grey and Light Grey ash, generated at higher severities. The means of the first group were higher than the observed in the second one. This indicates that ash produced lower temperatures release in solution higher amounts of TP. These divergences occur due temperature of combustion, affected specie, ash pH values and CaCO3 content, which affects the quantity of this element in solution. Discussions about these effects will be accurate in the communication.

Pereira, Paulo; Úbeda, Xavier; Martin, Deborah

2010-05-01

288

Pigment chemistry and colour of Pelargonium flowers  

Microsoft Academic Search

The major factors responsible for colour variation in a range of Pelargonium species and cultivars were shown to be the types and relative levels of pigments present. Variations in pH and copigment levels were not found to contribute significantly. Flowers with colours ranging from cream and pink through to deep purple, including salmon, orange and red, were studied. While either

Kevin A. Mitchell; Kenneth R. Markham; Murray R. Boase

1998-01-01

289

Mineralization in Rust-coloured Acarospora  

Microsoft Academic Search

The upper cortex and extracellular hyphal wall matrix are mineralized in both rust-coloured Acarospora sinopica and the paler A. smaragdula ‘f. subochracea’ in the form of microgranular or microbotryoidal phases. Analysis confirmed the distinctive colours are not simply due to hydrated iron oxides, as previously believed, and suggests mixed sulphide and oxide phases with little crystallinity, as well as other

O. William Purvis; Anton Kearsley; Gordon Cressey; Anna T. Crewe; Mats Wedin

2008-01-01

290

Visual Star Colours from Instrumental Photometry  

NASA Astrophysics Data System (ADS)

In order to display graphically the visual colours of stars and other astronomical objects, photometric broadband R, V, B colours are used to proxy for the r, g, b colours of the three visual sensors of the eye. From photometric Johnson B-V and V-R colour indices, R, V, and B magnitudes (V = 0) are calculated, and from these the respective brightnesses (r, v = 1 = g, and b) are calculated. After suitable normalization these are then placed in a ternary diagram having r, g, and b as the vertices. All B-V and V-R are adjusted so that the Sun falls in the same place as a blackbody at 5800 K. The resulting ternary plot shows all of its objects (stars, planets) in their visual colours at their relative positions in the ternary diagram. The star colours displayed on a computer monitor screen or as a print with a colour printer are more vivid than the usual visual impressions of isolated stars, undoubtedly because of properties of the dark-adapted eye, but double-star pairs with contrasting colours correspond nicely to telescopic visual impressions.

Kohman, Truman P.

2005-06-01

291

Vertex Colouring and Forbidden Subgraphs - A Survey  

Microsoft Academic Search

There is a great variety of colouring concepts and results in the literature. Here our focus is to survey results on vertex colourings of graphs defined in terms of forbidden induced subgraph conditions. Thus, one who wishes to obtain useful results from a graph coloring formulation of his problem must do more than just show that the problem is equivalent

Bert Randerath; Ingo Schiermeyer

2004-01-01

292

Generalized Colourings (Matrix Partitions) of Cographs  

Microsoft Academic Search

Ordinary colourings of cographs are well understood; we focus on more general colourings, known as matrix partitions. We show that all matrix partition problems for cographs admit polynomial time algorithms and forbidden induced subgraph characterizations, even for the list version of the problems. Cographs are the largest natural class of graphs that have been shown to have this property. We

Tomás Feder; Pavol Hell; Winfried Hochstättler

293

DIFFRACTION: QCD EFFECTS IN COLOUR SINGLET EXCHANGE  

E-print Network

DIFFRACTION: QCD EFFECTS IN COLOUR SINGLET EXCHANGE Anthony T. Doyle \\Lambda Department of Physics and the Tevatron are reviewed. A short introduction to the theoretical background is presented where colour singlet and the four­momentum transfer at the proton vertex, given by t = (P \\Gamma P 0 ) 2 . Fig. 1. Kinematic

Glasgow, University of

294

Skin colour and bilirubin in neonates  

Microsoft Academic Search

The correlation between the yellow colour of the skin and serum bilirubin concentration, reserve albumin concentration, and pH was investigated in 76 icteric neonates. Significant linear correlation existed between yellow colour of the skin and serum bilirubin concentration, reciprocal of the reserve albumin concentration, and the squared hydrogen ion concentration. Furthermore, the basic yellowness of the skin at birth correlated

A Knudsen; R Brodersen

1989-01-01

295

Brilliant Colours from a White Snow Cover  

ERIC Educational Resources Information Center

Surprisingly colourful views are possible from sparkling white snow. It is well known that similarly colourful features can exist in the sky whenever appropriate ice crystals are around. However, the transition of light reflection and refraction from ice crystals in the air to reflection and refraction from those in snow on the ground is not…

Vollmer, Michael; Shaw, Joseph A

2013-01-01

296

Polymorphism of the long-wavelength cone in normal human colour vision  

NASA Astrophysics Data System (ADS)

Colour vision is based on the presence of multiple classes of cone each of which contains a different type of photopigment1. Colour matching tests have long revealed that the normal human has three cone types. Results from these tests have also been used to provide estimates of cone spectral sensitivities2. There are significant variations in colour matches made by individuals whose colour vision is classified as normal3-6. Some of this is due to individual differences in preretinal absorption and photopigment density, but some is also believed to arise because there is variation in the spectral positioning of the cone pigments among those who have normal colour vision. We have used a sensitive colour matching test to examine the magnitude and nature of this individual variation and here report evidence for the existence of two different long-wavelength cone mechanisms in normal humans. The different patterns of colour matches made by male and female subjects indicate these two mechanisms are inherited as an X-chromosome linked trait.

Neitz, Jay; Jacobs, Gerald H.

1986-10-01

297

Environmental and Genetic Effects on Pigment-Based vs. Structural Component of Yellow Feather Colouration  

PubMed Central

Background Carotenoid plumage is of widespread use in bird communication. Carotenoid-based feather colouration has recently been shown to be dependent on both pigment concentration and feather structure. If these two components are determined differently, one plumage patch may potentially convey different aspects of individual quality. Methodology/Principal Findings We evaluated the effects of genetic and environmental factors on carotenoid-based yellow breast colouration of Great Tit (Parus major) nestlings. By partial cross-fostering, we separated the genetic and pre-natal vs. post-natal parental effects on both the structural and the pigment-based component of carotenoid-based plumage colouration. We also simultaneously manipulated the post-hatching environment by brood size manipulation. The structural component of nestling colouration reflected features of female colouration. On the other hand, the pigment-based component was more affected by rearing conditions presumably representing food quality. While the structural component was related to both origin- and environment-related factors, the pigment-based component seemed to be environment-dependent only. These results support the notion that pigment-based and structural components of feather colouration are determined differently. Conclusions/Significance Chromatic and achromatic components of carotenoid-based feather colouration reflected different aspects of individual quality and history, and thus may potentially form a multicomponent signal. PMID:22590581

Matrkova, Jana; Remes, Vladimir

2012-01-01

298

Limits of colour vision in dim light.  

PubMed

Humans and most vertebrates have duplex retinae with multiple cone types for colour vision in bright light, and one single rod type for achromatic vision in dim light. Instead of comparing signals from multiple spectral types of photoreceptors, such species use one highly sensitive receptor type thus improving the signal-to-noise ratio at night. However, the nocturnal hawkmoth Deilephila elpenor, the nocturnal bee Xylocopa tranquebarica and the nocturnal gecko Tarentola chazaliae can discriminate colours at extremely dim light intensities. To be able to do so, they sacrifice spatial and temporal resolution in favour of colour vision. We review what is known about colour vision in dim light, and compare colour vision thresholds with the optical sensitivity of the photoreceptors in selected animal species with lens and compound eyes. PMID:20883328

Kelber, Almut; Lind, Olle

2010-09-01

299

QTL dissection of the loss of green colour during post-anthesis grain maturation in two-rowed barley.  

PubMed

Ability to genetically manipulate the loss of green colour during grain maturation has potentials for increasing productivity, disease resistance, and drought and heat tolerance in crop plants. Two doubled haploid, two-rowed barley populations (Vlamingh × Buloke and VB9524 × ND11231*12) were monitored over 2 years for loss of green colour during grain filling using a portable active sensor. The aims were to determine the genomic regions that control trait heritability by quantitative trait locus (QTL) analysis, and to examine patterns of QTL-environment interactions under different conditions of water stress. In the Vlamingh × Buloke cross, broad-sense heritability estimate for loss of green colour (measured as the difference in sensor readings taken at anthesis and maturity, ?SRI) was 0.68, and 0.78 for the VB9524 × ND11231*12 population. In the VB9524 × ND11231*12 population, rapid loss of green colour was positively associated with grain yield and percent plump grains, but in the Vlamingh × Buloke population, a slower loss of green colour (low ?SRI) was associated with increased grain plumpness. With the aid of a dense array of single nucleotide polymorphisms (SNPs) and EST-derived SSR markers, a total of nine QTLs were detected across the two populations. Of these, a single major locus on the short arm of barley chromosome 5H was consistently linked with trait variation across the populations and multiple environments. The QTL was independent of flowering time and explained between 5.4 and 15.4 % of the variation observed in both populations, depending on the environment, and although a QTL × E interaction was detected, it was largely due to a change in the magnitude of the effect, rather than a change in direction. The results suggest that loss of green colour during grain maturation may be under the control of a simple genetic architecture, but a careful study of target populations and environments would be required for breeding purposes. PMID:23604470

Emebiri, Livinus C

2013-07-01

300

Measuring polyethylene wear in total knee arthroplasty by RSA: differences between weight-bearing and non-weight-bearing positioning.  

PubMed

Measuring the minimum-joint-space-width (mJSW) in total knee arthroplasty (TKA) in Roentgen stereophotogrammetric analysis (RSA) provides valuable information on polyethylene wear, a leading cause for TKA failure. Most existing studies use non-weight-bearing (NWB) patient positioning. The latter may compromise mJSW measurements due to knee laxity with subsequent non-contact between the TKA components. We investigated the difference in mJSW between weight-bearing (WB) and NWB images and the association with mediolateral (ML) knee stability. At one-year follow-up, 23 TKAs were included from an ongoing RSA study, and ML stability was evaluated. For each examination, the mJSW and femoral-tibial contact locations were measured. A linear regression model was used to analyze the association between the mJSW difference (NWB-WB) with the ML stability and contact locations. The mean mJSW difference was 0.28?mm medially and 0.20?mm laterally. Four TKAs had medium (5-9°) and 19 TKAs had high (<5°) ML stability. A higher mJSW difference was found for TKAs with medium stability (0.36?mm, P?=?0.01). In conclusion, mJSW measurements in existing (NWB) RSA studies are influenced by knee laxity, but may still provide information on wear progression based on TKA with high ML stability. A direct comparison of mJSW measurements from WB and NWB data is not possible. PMID:24395396

van Ijsseldijk, Emiel A; Valstar, Edward R; Stoel, Berend C; de Ridder, Ruud; Nelissen, Rob G H H; Kaptein, Bart L

2014-04-01

301

Genetics of colour traits in common vetch ( Vicia sativa L.)  

Microsoft Academic Search

Five parents of common vetch (Vicia sativa L.) having orange\\/beige cotyledon colour, brown\\/white testa colour, purple\\/green seedling colour and purple\\/white flower colour were crossed as a full diallele set. The inheritance patterns of cotyledon, testa or seed coat colour, flower and seedling colour, were studied by analyzing their F1, F2, BC1 and BC2 generations. The segregation pattern in F2, BC1

Doza M. S. Chowdhury; Jane M. Rathjen; Max E. Tate; Glenn McDonald

2004-01-01

302

Sources of Differences in On-Orbit Total Solar Irradiance Measurements and Description of Proposed Laboratory Intercomparison  

NASA Technical Reports Server (NTRS)

There is a 5 W/sq m (about 0.35 %) difference between current on-orbit Total Solar Irradiance (TSI) measurements. On 18-20 July 2005, a workshop was held at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland that focused on understanding possible reasons for this difference, through an examination of the instrument designs, calibration approaches, and appropriate measurement equations. The instruments studied in that workshop included the Active Cavity Radiometer Irradiance Monitor III (ACRIM III) on the Active Cavity Radiometer Irradiance Monitor SATellite (ACRIMSAT), the Total Irradiance Monitor (TIM) on the Solar Radiation and Climate Experiment (SORCE), the Variability of solar IRradiance and Gravity Oscillations (VIRGO) on the Solar and Heliospheric Observatory (SOHO), and the Earth Radiation Budget Experiment (ERBE) on the Earth Radiation Budget Satellite (ERBS). Presentations for each instrument included descriptions of its design, its measurement equation and uncertainty budget, and the methods used to assess on-orbit degradation. The workshop also included a session on satellite- and ground-based instrument comparisons and a session on laboratory-based comparisons and the application of new laboratory comparison techniques. The workshop has led to investigations of the effects of diffraction and of aperture area measurements on the differences between instruments. In addition, a laboratory-based instrument comparison is proposed that uses optical power measurements (with lasers that underEll the apertures of the TSI instruments), irradiance measurements (with lasers that overfill the apertures of the TSI instrument), and a cryogenic electrical substitution radiometer as a standard for comparing the instruments. A summary of the workshop and an overview of the proposed research efforts are presented here.

Butler, J.J.; Johnson, B. C.; Rice, J. P.; Shirley, E. L.; Barnes, R.A.

2008-01-01

303

Nectar, not colour, may lure insects to their death  

PubMed Central

We experimentally demonstrate in the field that prey of the carnivorous plant Sarracenia purpurea are attracted to sugar, not to colour. Prey capture (either all taxa summed or individual common taxa considered separately) was not associated with total red area or patterning on pitchers of living pitcher plants. We separated effects of nectar availability and coloration using painted ‘pseudopitchers’, half of which were coated with sugar solution. Unsugared pseudopitchers captured virtually no prey, whereas pseudopitchers with sugar solution captured the same amount of prey as living pitchers. In contrast to a recent study that associated red coloration with prey capture but that lacked controls for nectar availability, we infer that nectar, not colour, is the primary means by which pitcher plants attract prey. PMID:19429649

Bennett, Katherine F.; Ellison, Aaron M.

2009-01-01

304

Prevalence of cytomegalovirus infection and its role in total immunoglobulin pattern in Iranian patients with different subtypes of multiple sclerosis.  

PubMed

Multiple sclerosis (MS) is the most common autoimmune disease characterized by multifocal areas of inflammatory demyelination within the central nervous system. Cytomegalovirus (CMV) has a complex pathobiology and in most cases is simply asymptomatic. There is some recent controversy over the role of CMV in the pathology of MS. The aim of this study was to evaluate active CMV infection and its effect on the humoral immunity in patients with MS. Serum, plasma, peripheral blood mononuclear cells (PBMCs), saliva and urine collected from MS patients (n=78) and healthy subjects (n=123) were screened for the presence of anti-CMV antibodies and CMV-DNA by nephelometric and PCR methods. Concentrations of total antibodies in MS subtypes were measured using both nephelometric and enzyme linked fluorescent assay (ELFA) techniques. The results extend the observation of an increased frequency of CMV-DNA in patients, in contrast with controls (p<0.001). Furthermore, systemic CMV infections were found in 25.5% of patients and only 3.2% of controls (p<0.001). There was significant difference in the titers of anti-CMV IgG and total IgE in patient and controls (P<0.001). These results support the hypothesis that CMV may contribute to MS thought to establish systemic infection process and induce immune response. PMID:21811746

Sanadgol, Nima; Ramroodi, Nourollah; Ahmadi, Ghasem Ali; Komijani, Majid; Moghtaderi, Ali; Bouzari, Majid; Rezaei, Marzieh; Kardi, Mohammad Taghi; Dabiri, Soroush; Moradi, Malek; Sanadgol, Ehsan

2011-07-01

305

Different stroke volumes for the left and right ventricles in the moving-actuator type total artificial heart.  

PubMed

A new electromechanical moving-actuator type total artificial heart (TAH) has been developed to solve the imbalance problem without an extra compliance chamber. A different stroke volume was achieved by the large left sac size and the asymmetry of the actuator motion referred to the center position. The left ventricle consists of a double sac with the outer sac attached to the actuator providing active diastolic filling, while the double sac of the right ventricle being free from the actuator, and having sufficient suction produced due to the rigid pump housing. The stroke volume difference between the left and right sac is compensated through the air in the interventricular space of the variable volume (VV) space. Computer simulation based on the geometrical relationships between the blood sacs and the actuator was performed to simulate the physical mechanisms of the moving-actuator type TAH. Results were then compared with the measured pressure changes in various chambers of the pump and the stroke volume differences in mock circulation test. In two acute calf experiments, the balanced left and right atrial pressures were achieved in the moving-actuator type TAH without an extra compliance chamber. PMID:8458672

Min, B; Kim, I; Kim, H

1993-01-01

306

Total phenolic contents and free radical scavenging activities of different extracts of seabuckthorn (Hippophae rhamnoides) pomace without seeds.  

PubMed

In this study, 100% methanolic extract (ME), 70% aqua-methanolic extract (AME) and 100% aqueous extract of seabuckthorn byproduct were used to evaluate antioxidant activity. The total phenolic contents were high in AME (84.28 ± 1.58 mg of Gallic Acid Equivalent (GAE)/gm of extract) compared to other extracts. All the extracts scavenged different in vitro radicals in a concentration-dependent manner. The IC(50) values were lowest in AME for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, 2,2-diphenyl-1-picrylhydrazyl, superoxide and nitric oxide radicals, while ME had lowest values for hydroxyl radicals. The reducing power of the extracts increased in a dose-dependent manner and was highest in AME. The findings of this study revealed that seabuckthorn pomace without seed is one of the important resources as an antioxidant for food, pharmaceuticals, cosmetic or nutraceutical industries. PMID:21875373

Varshneya, Chandresh; Kant, Vinay; Mehta, Madhuri

2012-03-01

307

Dietary total antioxidant capacity from different assays in relation to serum C-reactive protein among young Japanese women  

PubMed Central

Background The association between dietary total antioxidant capacity (TAC) from different assays and serum C-reactive protein (CRP) has not been assessed in non-Western populations. We examined the association between dietary TAC and serum CRP concentration in young Japanese women using different four TAC assays. Methods The subjects were 443 young Japanese women aged 18–22?years. Dietary TAC was assessed with a self-administered diet history questionnaire and the TAC value of each food using the following four assays: ferric reducing ability of plasma (FRAP); oxygen radical absorbance capacity (ORAC); Trolox equivalent antioxidant capacity (TEAC); and total radical-trapping antioxidant parameter (TRAP). Serum CRP concentrations were measured by highly sensitive nephelometry. Results The major contributor to dietary TAC was green, barley, and oolong tea (FRAP: 53%, ORAC: 45%, TEAC: 36%, and TRAP: 44%). The prevalence of elevated CRP concentrations (? 1?mg/L) was 5.6%. TAC from FRAP was inversely associated with serum CRP concentrations (adjusted odds ratio [OR] for elevated CRP concentration in high [compared with low] dietary TAC group: 0.39 [95% confidence interval (CI): 0.16-0.98]; P?=?0.04). TAC from ORAC was inversely associated with CRP, although the association was not significant (OR: 0.48 [95% CI: 0.20-1.14]; P?=?0.10). TAC from TEAC was inversely associated with CRP (OR: 0.32 [95% CI: 0.12-0.82]; P?=?0.02), as was TAC from TRAP (OR: 0.31 [95% CI: 0.12-0.81]; P?=?0.02). Conclusions Dietary TAC was inversely associated with serum CRP concentration in young Japanese women regardless of assay. Further studies are needed in other populations to confirm these results. PMID:23110638

2012-01-01

308

Physicochemical and physiological basis of dichromatic colour  

NASA Astrophysics Data System (ADS)

Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here, we report that evident change of the hue of the colour (i.e., from green to red) is due to a change in concentration or the thickness of a layer in some exceptional substances such as pumpkin seed oil or an aqueous solution of bromophenol blue. In some regions of Central Europe, salad dressing is made preferably with the pumpkin seed oil, which has a strong characteristic nut-like taste and remarkable properties of the colour: it appears red in a bottle, but green when served as a salad dressing. The colour of the pumpkin seed oil was previously described as brownish yellow, dark green, dark green to red ochre or dark reddish brown to light yellow green. We elucidated the physicochemical and physiological basis of such dichromatism by Beer-Lambert law and by the characteristics of human colour perception. Our concept was corroborated by the outcome of calculations of colour from spectral properties using colour matching functions. We found that dichromatism is observed if the absorption spectrum of any substance has at least two local minima: one wide but shallow and one narrow but deep local minimum.

Kreft, Samo; Kreft, Marko

2007-11-01

309

Colouration and Colour Changes of the Fiddler Crab, Uca capricornis: A Descriptive Study  

PubMed Central

Colour changes in animals may be triggered by a variety of social and environmental factors and may occur over a matter of seconds or months. Crustaceans, like fiddler crabs (genus Uca), are particularly adept at changing their colour and have been the focus of numerous studies. However, few of these studies have attempted to quantitatively describe the individual variation in colour and pattern or their adaptive significance. This paper quantitatively describes the colour patterns of the fiddler crab Uca capricornis and their ability to change on a socially significant timescale. The most dramatic changes in colour pattern are associated with moulting. These ontogenetic changes result in a general reduction of the colour pattern with increasing size, although females are more colourful and variable than similarly-sized males. Uca capricornis are also capable of rapid colour changes in response to stress, but show no endogenous rhythms associated with the semilunar and tidal cycles commonly reported in other fiddler crabs. The extreme colour polymorphism and the relative stability of the colour patterns in Uca capricornis are consistent with their use in visually mediated mate recognition. PMID:18286186

Detto, Tanya; Hemmi, Jan M.; Backwell, Patricia R. Y.

2008-01-01

310

Phenolic compounds and the colour of oranges subjected to a combination treatment of waxing and irradiation  

NASA Astrophysics Data System (ADS)

The effects of waxing, irradiation dose and storage on phenolics and colour of irradiated oranges were investigated. Mature oranges ( Maroc late) waxed or unwaxed were treated with 0, 1 or 2 kGy radiation and stored up to 9 weeks at 20°C and 40-50% r.h. Colour of the oranges, total phenols and flavones in the peel were measured. Phenolic compounds increased with irradiation dose and storage time. Hue angle, value and chroma of the orange colour were more affected by waxing and storage time than the irradiation treatment. Changes in the phenolic compounds were linked with changes in the redness and saturation of the orange colour. Irradiation stimulated synthesis of flavones; waxing controlled changes induced by irradiation.

Moussaid, M.; Lacroix, M.; Nketsia-Tabiri, J.; Boubekri, C.

2000-03-01

311

Comparison of total suspended particulate concentration-response relationships for respiratory symptoms between Chinese children with a different susceptibility status.  

PubMed

Few studies have explored concentration-response (C-R) relationships between levels of particulate matter (PM) and respiratory morbidity in terms of the susceptibility of children to respiratory diseases. We sought to determine whether the shapes of C-R curves for comparing total suspended particle (TSP) concentration versus the adjusted prevalence of bronchitis (persistent cough or phlegm) and asthma (current wheeze or asthma) symptoms between children with a different susceptibility status. We used the restricted cubic spline (RCS) function to characterize the C-R relationships between TSP and the adjusted prevalence rates of four respiratory symptoms, after controlling for possible confounding by SO(2) and NO(2) levels, in 11,860 children selected from 18 districts of six cities in Liaoning province. Susceptible children exhibited a 2- to 3-fold elevation in the prevalence of all four respiratory symptoms across the entire TSP range (188-689?g/m(3)). Significant differences in the shapes of C-R curves were evident in children with symptoms of bronchitis (ballistic "S"-shaped curves) and asthma (flattened "U"-shaped curves), as well as between the low and high TSP ranges of such curves, when children were grouped by susceptibility status. A significant linear association between TSP levels and current asthma prevalence was found only among susceptible children exposed to high levels of TSP. The shapes and properties of the TSP-morbidity C-R curves differed significantly by type of respiratory symptom, susceptibility status, and TSP range. More work is required to characterize CR relationships in terms of susceptibility status in countries with different PM levels. PMID:22342355

Pan, Guowei; Kagawa, Jun; Zhang, Shujuan; Feng, Yiping; Takahashi, Ken; Kan, Haidong; Wang, Ping; Yin, Hongbo; Yu, Lianzheng; Na, Jun

2012-04-01

312

Analysis of Trans-Neptunian and Centaur colours: continuous trend or grouping?  

NASA Astrophysics Data System (ADS)

We report the results of the first statistical analysis of colours (B-V, V-R, V-I, and V-J) of the Trans-Neptunian and Centaur populations. Using the same statistical techniques applied to define the current asteroid taxonomy, we find a continuous spread of the objects between neutral colour to very red. Pushing further the analysis, the TNOs may be split into four groups. The differences in colour content are interpreted as a consequence of the TNOs evolution (i.e. collisional history, space weathering, ...)

Barucci, M. A.; Fulchignoni, M.; Birlan, M.; Doressoundiram, A.; Romon, J.; Boehnhardt, H.

2001-06-01

313

Survival of Brown Colour in Diamond During Storage in the Subcontinental Lithospheric Mantle  

NASA Astrophysics Data System (ADS)

Brown is the most common colour of natural diamond. This colour is generally associated with plastic deformation of the crystal structure, which is imparted during residence in the mantle. Dislocation movement generates vacancies, which aggregate into clusters of perhaps 30-60 vacancies. The resulting electronic configuration leads to the broad, featureless absorption pattern associated with common brown colour. It is well-established that the common brown colour can be removed by high-pressure-high-temperature (HPHT) treatment. The process involves pressures and temperatures in the range of 5-9 GPa and 1800-2700 ° C, respectively. The treatment may take several minutes or hours. It has been suggested that the same colour removal process operates continuously in the subcontinental lithospheric mantle, causing any brown diamonds in the diamond window to quickly lose their colour. The present study examined the validity of this suggestion. Temperature is the important difference between HPHT conditions and diamond window conditions. Higher temperatures result in faster colour removal. HPHT treatment occurs at 1800-2700 ° C, whereas inclusion thermometry places most lithospheric diamonds in the range of 900-1400 ° C. Destruction of the brown colour centre involves breaking up vacancy clusters. How quickly this can be done depends on the concentration of clusters as well as the rate constant. The rate constant is changes with temperature, according to the Arrhenius equation. The key to this relationship is the activation energy required for the breakup of a vacancy cluster. This activation energy can be estimated as the energy of an isolated monovacancy, minus the energy per vacancy of the cluster, plus the vacancy migration energy. A value of 7.7±0.3 eV is obtained using data from recent literature. For any given brown diamond, the rate constant determines the time needed to remove a certain amount of colour. The Arrhenius equation can be rearranged to show how this reaction time varies with temperature. Thus, the activation energy can be used in conjunction with experimental HPHT data to extrapolate reaction times from HPHT temperatures to lithospheric mantle temperatures. For a certain reduction in brown colour produced by HPHT (T1, t1), the equation below shows the time required (t2) to produce the same reduction at a different temperature (T2): ln(t2) = ln(t1) + (Ea/k)(1/T2-1/T1) where Ea is activation energy, k is the Boltzmann constant, and temperatures are in kelvins. The error in activation energy causes large, increasing error as the temperature difference between T1 and T2increases. Nevertheless, the time required to destroy brown colour in the lithospheric mantle is significant at the scale of geological time. Brown diamonds should easily maintain brown colour during cooler mantle storage at or below 1000 ° C. Warmer temperatures toward the base of the lithosphere may be able to reduce or eliminate brown colour within a reasonable geological time frame. However, the survival of brown colour in the lithospheric mantle does not require the colour to be formed late in the storage history nor does it require metastable storage in the graphite stability field. Additionally, preliminary measurements of diamond crystal strain suggest that brown colour removal in the lithospheric mantle is, at least, not a common occurrence. Mosaic spreading was gauged in 18 untreated natural diamonds using micro-X-ray diffraction (?XRD) ?-dimension peak widths. None of the colourless diamonds examined have a large residual mosaic spread, as should be expected for a diamond that has been deformed and turned brown, but later lost its brown colour. Despite the limited sample size, the results support some capacity for the survival of brown colour in the mantle.

Smith, Evan; Helmstaedt, Herwart; Flemming, Roberta

2010-05-01

314

The impacts of prescribed moorland burning on water colour and dissolved organic carbon: a critical synthesis.  

PubMed

Discolouration of natural surface waters due to the humic component of dissolved organic carbon (DOC) is a costly problem for water supply companies. This paper reviews what is known about the impacts of prescribed moorland vegetation burning on water colour. Relevant research has taken place at three scales: laboratory experiments on peat cores, plot scale sampling of soil waters and catchment scale sampling of stream waters. While laboratory studies suggest burning increases colour production, the evidence from catchment and plot studies is contradictory. Plot studies suggest colour production may decrease or remain unchanged following burning although there is evidence for some transient changes. Catchment studies suggest prescribed moorland burning causes stream water colour to increase, although in most cases the evidence is not clear cut since most studies could not clearly disentangle the effects of burning from those of vegetation cover. The differences in findings between plot and catchment studies may be explained by: i) the short-term nature of some studies which do not measure long-term response and recovery times to burning; ii) the lack of colour measurements from shallow soil depths which contribute more to streamflow than soil water from deeper in the peat; and iii) the possibility of hydrological interactions occurring between different experimental plots at some sites. Additionally, the increase in recent patch burning in some catchments that has been statistically attributed by some authors to increases in stream water colour cannot be reconciled with theoretical calculations. When dilution with waters derived from other parts of the catchment are taken into account, large values of colour have to be theoretically derived from those recently burnt areas that occupy a small proportion of the catchment area in order to balance the change in stream water colour observed in recent years. Therefore, much further process-based work is required to properly investigate whether prescribed vegetation burning is a direct driver of enhanced colour and DOC in upland streams, rivers and lakes. PMID:22406849

Holden, J; Chapman, P J; Palmer, S M; Kay, P; Grayson, R

2012-06-30

315

Avoidance of achromatic colours by bees provides a private niche for hummingbirds.  

PubMed

That hummingbird-pollinated plants predominantly have red flowers has been known for decades, but well-investigated research studies are still rare. Preference tests have shown that hummingbirds do not have an innate preference for red colours. In addition, hummingbirds do not depend solely upon red flowers, because white-flowered hummingbird-pollinated plants are also common and temporarily abundant. Here we show that both white and red hummingbird-pollinated flowers differ from bee-pollinated flowers in their reflection properties for ultraviolet (UV) light. Hummingbird-pollinated red flowers are on average less UV reflective, and white hummingbird-pollinated flowers are more UV reflective than the same coloured bee-pollinated ones. In preference tests with artificial flowers, neotropical orchid bees prefer red UV-reflecting artificial flowers and white UV-nonreflecting flowers over red and white flowers with the opposite UV properties. By contrast, hummingbirds showed no preference for any colour in the same tests. Plotting floral colours and test stimuli into the honeybees' perceptual colour space suggests that the less attractive colours are achromatic for bees and therefore more difficult to detect against the background. This underlying colour preference in bees might provide hummingbirds with a private niche that is not attractive to bees. PMID:21490268

Lunau, Klaus; Papiorek, Sarah; Eltz, Thomas; Sazima, Marlies

2011-05-01

316

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

PubMed Central

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

Vereecken, Nicolas J.; Schiestl, Florian P.

2009-01-01

317

Why do Manduca sexta feed from white flowers? Innate and learnt colour preferences in a hawkmoth  

NASA Astrophysics Data System (ADS)

Flower colour is an important signal used by flowering plants to attract pollinators. Many anthophilous insects have an innate colour preference that is displayed during their first foraging bouts and which could help them locate their first nectar reward. Nevertheless, learning capabilities allow insects to switch their colour preferences with experience and thus, to track variation in floral nectar availability. Manduca sexta, a crepuscular hawkmoth widely studied as a model system for sensory physiology and behaviour, visits mostly white, night-blooming flowers lacking UV reflectance throughout its range in the Americas. Nevertheless, the spectral sensitivity of the feeding behaviour of naïve moths shows a narrow peak around 450 nm wavelengths, suggesting an innate preference for the colour blue. Under more natural conditions (i.e. broader wavelength reflectance) than in previous studies, we used dual choice experiments with blue- and white-coloured feeders to investigate the innate preference of naïve moths and trained different groups to each colour to evaluate their learning capabilities. We confirmed the innate preference of M. sexta for blue and found that these moths were able to switch colour preferences after training experience. These results unequivocally demonstrate that M. sexta moths innately prefer blue when presented against white flower models and offer novel experimental evidence supporting the hypothesis that learning capabilities could be involved in their foraging preferences, including their widely observed attraction to white flowers in nature.

Goyret, Joaquín; Pfaff, Michael; Raguso, Robert A.; Kelber, Almut

2008-06-01

318

Colour change of soft denture liners after storage in coffee and coke.  

PubMed

This study was to evaluate the colour change of soft denture liners after thermocycling and storage in coffee and coke. Four liners, two silicone-based (Sofreliner S and Reline GS) and two acrylic resin-based (Soft Confort and Dentuflex), were evaluated in this study. Ten samples were obtained for each group. After 2000 cycles of thermocycling with baths of 5°C and 55°C, five samples were stored in coffee and the remaining samples in coke. The colour alteration was evaluated in a reflection spectrophotometer before and after thermocycling, and after 1, 3, 24, 48 and 96h of storage in coffee and coke. Data were submitted to anova and Tukey's HSD test (?=0.05). Thermocycling and storage period represented a higher statistically significant influence for the resin liners than for the silicone materials. Coke did not influence the colour stability of the materials during storage. However, the coffee solution generated statistically significant colour alteration in the material Soft Confort. In the comparison between the coffee and coke solutions, there was no statistically significant difference for colour alteration only for the material Dentuflex. The silicone liners presented better colour stability following thermocycling and storage independent of the solution. The coffee solution was a statistically significant factor for colour alteration of the material Soft Confort. PMID:20082643

Goiato, Marcelo Coelho; Zuccolotti, Bruna Carolina Rossatti; Moreno, Amália; dos Santos, Daniela Micheline; Pesqueira, Aldiéris Alves; Dekon, Stefan Fiuza de Carvalho

2011-06-01

319

Implant based differences in adverse local tissue reaction in failed total hip arthroplasties: a morphological and immunohistochemical study  

PubMed Central

Background Adverse local tissue reaction (ALTR) is characterized by periprosthetic soft tissue inflammation composed of a mixed inflammatory cell infiltrate, extensive soft tissue necrosis, and vascular changes. Multiple hip implant classes have been reported to result in ALTR, and clinical differences may represent variation in the soft tissue response at the cellular and tissue levels. The purpose of this study was to describe similarities and differences in periprosthetic tissue structure, organization, and cellular composition by conventional histology and immunohistochemistry in ALTR resulting from two common total hip arthroplasty (THA) implant classes. Methods Consecutive patients presenting with ALTR from two major hip implant classes (N?=?54 patients with Dual-Modular Neck implant; N?=?14 patients with Metal-on-Metal implant) were identified from our prospective Osteolysis Tissue Database and Repository. Clinical characteristics including age, sex, BMI, length of implantation, and serum metal ion levels were recorded. Retrieved synovial tissue morphology was graded using light microscopy and cellular composition was assessed using immunohistochemistry. Results Length of implantation was shorter in the DMN group versus MoM THA group (21.3 [8.4] months versus 43.6 [13.8] months respectively; p?differences in implant performance. Morphologic examination revealed a common spectrum of neo-synovial proliferation and necrosis in both groups. Macrophages were more commonly present in diffuse sheets (Grade 3) in the MoM relative to DMN group (p?=?0.016). Perivascular lymphocytes with germinal centers (Grade 4) were more common in the DMN group, which trended towards significance (p?=?0.066). Qualitative differences in corrosion product morphology were seen between the two groups. Immunohistochemistry showed features of a CD4 and GATA-3 rich lymphocyte reaction in both implants, with increased ratios of perivascular T-cell relative to B-cell markers in the DMN relative to the MoM group (p?=?0.032). Conclusion Our results demonstrate that both implant classes display common features of neo-synovial proliferation and necrosis with a CD4 and GATA-3 rich inflammatory infiltrate. Qualitative differences in corrosion product appearance, macrophage morphology, and lymphocyte distributions were seen between the two implant types. Our data suggests that ALTR represents a histological spectrum with implant-based features. PMID:25242891

2014-01-01

320

Blending of animal colour patterns by hybridization  

PubMed Central

Biologists have long been fascinated by the amazing diversity of animal colour patterns. Despite much interest, the underlying evolutionary and developmental mechanisms contributing to their rich variety remain largely unknown, especially the vivid and complex colour patterns seen in vertebrates. Here, we show that complex and camouflaged animal markings can be formed by the 'blending' of simple colour patterns. A mathematical model predicts that crossing between animals having inverted spot patterns (for example, 'light spots on a dark background' and 'dark spots on a light background') will necessarily result in hybrid offspring that have camouflaged labyrinthine patterns as 'blended' intermediate phenotypes. We confirmed the broad applicability of the model prediction by empirical examination of natural and artificial hybrids of salmonid fish. Our results suggest an unexplored evolutionary process by means of 'pattern blending', as one of the possible mechanisms underlying colour pattern diversity and hybrid speciation. PMID:20842190

Miyazawa, Seita; Okamoto, Michitoshi; Kondo, Shigeru

2010-01-01

321

Light-emitting diodes with variable colours from polymer blends  

Microsoft Academic Search

THE range of materials now available for polymer-based light-emitting diodes (LEDs) is such that electroluminescence can be obtained throughout the visible spectrum1 12. Here we show that, by blending polymers with different emission and charge-transport characteristics, LEDs can be fabricated in which the emission col-our varies as a function of the operating voltage. This phenomenon arises from the self-organizing properties

M. Berggren; O. Inganäs; G. Gustafsson; J. Rasmusson; M. R. Andersson; T. Hjertberg; O. Wennerström

1994-01-01

322

Inheritance of fruit colour in the Solanum nigrum complex  

Microsoft Academic Search

In theSolanum nigrum complex there is wide variability in the fruit colour. In 17 accessions representing diploids, tetraploids and hexaploids,\\u000a dark shining blue, dull blue, bright red, orange red, yellowish-red and translucent green were observed in the different accessions.\\u000a Blue is inherited as dominant over red and translucent green; however, the results obtained in crosses between blue and translucent\\u000a green

J. Venkateswarlu; M. Krishna Rao

1971-01-01

323

Do feather-degrading bacteria actually degrade feather colour? No significant effects of plumage microbiome modifications on feather colouration in wild great tits.  

PubMed

Parasites are known to exert selective pressures on host life history traits since the energy and nutrients needed to mount an immune response are no longer available to invest in other functions. Bird feathers harbour numerous microorganisms, some of which are able to degrade feather keratin (keratinolytic microorganisms) and affect feather integrity and colouration in vitro. Although named "feather-degrading" microorganisms, experimental evidence for their effects on feathers of free-living birds is still lacking. Here, we tested whether (i) keratinolytic microorganisms can degrade feathers in vivo and thus modify the colour of feathers during the nesting period and (ii) whether feather microorganisms have a long-term effect on the investment in colouration of newly moulted feathers. We designed treatments to either favour or inhibit bacterial growth, thus experimentally modifying plumage bacterial communities, in a wild breeding population of great tits (Parus major). Our analyses revealed no significant effects of the treatments on feather colours. Moreover, we found that differences in bacterial exposure during nesting did not significantly affect the colouration of newly moulted feathers. Our results suggest that significant feather degradation obtained during in vitro studies could have led to an overestimation of the potential of keratinolytic microorganisms to shape feather colouration in free-living birds. PMID:25228345

Jacob, Staffan; Colmas, Léa; Parthuisot, Nathalie; Heeb, Philipp

2014-11-01

324

Impact of colour pigments on biochemical parameters of bivalve, Lamellidens marginalis.  

PubMed

The present study was carried out to investigate the effect of colour pigments used for painting the decorative articles like idols, on the freshwater bivalve, Lamellidens marginalis. The effects of subchronic exposure were studied by the changes in the biochemical constituents like total protein, glycogen and lactic acid, in different tissues like muscle, mantle, gills, foot, hepatopancreas and gonads for 10 and 20 days period. The glycogen contents in the muscle, mantle and gonads were significantly decreased with increase in concentration of colour pigments. It decreased from 26.77 mg gm(-1) in control to 19.17 mg gm(-1) at 900 ppm after 20 days of exposure; whereas protein contents in the tissues studied decreased significantly from 22.5 mg gm(-1) in control to 15.5 mg gm(-1) at 900 ppm after 10 days of exposure. The increase in lactic acid content in all the tissues except gills and gonads may be due to acute hypoxia. PMID:24620590

Phadnis, S D; Chandagade, C A; Jadhav, V V; Raut, P D

2013-03-01

325

Tracking colour objects using adaptive mixture models  

Microsoft Academic Search

Abstract The use of adaptive Gaussian mixtures to model the colour distributions of objects is described. These models are used to perform robust, real-time tracking under varying illumination, viewing geometry and camera parameters. Observed log-likelihood measurements were used to perform selective adaptation. q,1999 Elsevier Science B.V. All rights reserved. Keywords: Real-time tracking; Colour model; Gaussian mixture model; Adaptive learning

Stephen J. Mckenna; Yogesh Raja; Shaogang Gong

1999-01-01

326

Plants and colour: Flowers and pollination  

NASA Astrophysics Data System (ADS)

While there is a range of colours found in plants the predominant colour is green. Pigments in plants have several roles e.g. photosynthesis and signalling. If colour is to be used as a signal then it must stand out from green. However, one should be aware that there are also coloured compounds where we have not yet fully investigated the role of colour in their functions—they may have roles in, for example, defence or heat exchange. In this paper, we will describe the basic chemistry of the major pigments found in plants and especially floral pigments. We will then discuss their locations in parts of the flower (such as sepals, petals, pollen and nectar), the cells in which they are found and their sub-cellular locations. Floral pigments have a large role to play in pollination of flowers by animals. They can and are modified in many ways during the development of flowers in nature, for example, at emergence and post-pollination. There are a range of biochemical mechanisms of colour change both within flowers and in isolated pigments. Some of the factors influencing colour are temperature, co-pigments, pH, metals, sugars, anthocyanin stacking and cell shape. There is a renewed interest in analysing floral pigments and how they are modified partly because of advances in recombinant DNA technologies, but also because of pollinators and their significance to biodiversity and for evolutionary studies. There is continued strong interest from the horticultural industry for the introduction of new colours e.g. the blue rose and for the exploitation of natural dyes. Funding in this area may impact future research in a potentially beneficial way but it must not deflect us from science-based conservation.

Miller, Renee; Owens, Simon J.; Rørslett, Bjørn

2011-03-01

327

Contextual service loading by dependency graph colouring  

Microsoft Academic Search

While installing applications on mobiles devices, we may face issues due to the limit of the device resources. In this paper, we propose AxSeL: A conteXtual Service Loader that considers services-oriented applications and loads them from a distant repository. Services dependencies are represented in a graph that is coloured considering the devices and services constraints. The graph colouring aims to

Amira Ben Hamida; Frédéric Le Mouël; Stéphane Frénot; Mohamed Ben Ahmed

2008-01-01

328

Colour Reagent for Paper Chromatography of Steroids  

Microsoft Academic Search

FOR the paper chromatography of steroids several colour reagents are used, such as 2,4-dinitrophenyl-hydrazine, Zimmermann's reagent, phosphomolybdic acid, antimony trichloride, etc. Their common defect is that the reagent gives some colour with the paper itself, and so the contrast between spot and paper is too small. We have found that acid aniline phthalate in alcoholic solution-the reagent Partridge used for

A. Bodánszky; J. Kollonitsch

1955-01-01

329

THE COLOUR GLASS CONDENSATE: AN INTRODUCTION  

SciTech Connect

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

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

2001-08-06

330

Partitioning Based Algorithms for Some Colouring Problems  

Microsoft Academic Search

We discuss four variants of the graph colouring problem, and present algorithms for solving them. The problems are k-Colourability, Max Ind k-COL, Max Val k-COL, and, finally, Max k-COL, which is the unweighted case of the Max k-Cut problem. The algorithms are based on the idea of partitioning the domain of the problems into disjoint subsets, and then considering all

Ola Angelsmark; Johan Thapper

2005-01-01

331

Colour television image analysis of carious lesions  

Microsoft Academic Search

The new technique of colour television image analysis has been used to produce seven-colour contour maps of the radiodensity\\u000a of micro-radiographs of enamel caries. This method permits the detailed measurement of the mineral content of enamel carious\\u000a lesions to a sensitivity of ±3% of the level of complete mineralisation. By selection of appropriate aluminium step-wedges,\\u000a exposed simultaneously with the tooth

J. C. Rodda; K. V. Mortimer; E. D. Williams

1975-01-01

332

Physicochemical and physiological basis of dichromatic colour  

Microsoft Academic Search

Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties\\u000a of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here,\\u000a we report that evident change of the hue of the colour (i.e., from green to red) is due to a change

Samo Kreft; Marko Kreft

2007-01-01

333

Angle-Insensitive Structural Colours based on Metallic Nanocavities and Coloured Pixels beyond the Diffraction Limit  

PubMed Central

To move beyond colorant-based pigmentation display technologies, a variety of photonic and plasmonic crystal based structures have been designed and applied as colour filters. Nanostructure based colour filtering offers increased efficiencies, low power consumption, slim dimensions, and enhanced resolution. However, incident angle tolerance still needs to be improved. In this work, we propose a new scheme through localized resonance in metallic nanoslits by light funneling. Angle insensitive colour filters up to ±80 degrees have been achieved, capable of wide colour tunability across the entire visible band with pixel size beyond the diffraction limit (~?/2). This work opens the door to angle insensitive manipulation of light with structural filtering. PMID:23378925

Wu, Yi-Kuei Ryan; Hollowell, Andrew E.; Zhang, Cheng; Guo, L. Jay

2013-01-01

334

Salience of Primary and Secondary Colours in Infancy  

ERIC Educational Resources Information Center

Primary colour terms ("black", "white", "red", "green", "yellow", and "blue") are more fundamental in colour language than secondary colour terms ("pink", "purple", "orange", "brown", and "grey"). Here, we assess whether this distinction exists in the absence of language, by investigating whether primary colours attract and sustain preverbal…

Franklin, Anna; Pitchford, Nicola; Hart, Lynsey; Davies, Ian R. L.; Clausse, Samantha; Jennings, Siobhan

2008-01-01

335

Canvas: An Intelligent Colour Selection Tool For VDU Images  

Microsoft Academic Search

CANVAS is a palette-driven system for colour selection in the density slicing of single-band imagery. By incorporating intelligence on the visual distinction and ordering of colours, the system can operate in several modes. Colours can be selected individually from the palettes or by the system, which maximises the apparent distinction between them. Colour series with unipolar, repeating unipolar and bipolar

G. A. Gill; A. D. Trigg

1988-01-01

336

Facial parity edge colouring of plane pseudographs Jlius Czapa  

E-print Network

is presently known as the Four Colour Theorem (4CT). From the 4CT the following result follows, see [1510, 05C15 1. Introduction The famous Four Colour Problem has served as a motivation for many equivalent colour- ing problems, see e.g. the book of Saaty and Kainen [15]. The Four Colour Problem

Paris-Sud XI, Université de

337

Fano colourings of cubic graphs and the Fulkerson Conjecture  

Microsoft Academic Search

A Fano colouring is a colouring of the edges of a cubic graph by points of the Fano plane such that the colours of any three mutually adjacent edges form a line of the Fano plane. It has recently been shown by Holroyd and Skoviera (J. Combin. Theory Ser. B, to appear) that a cubic graph has a Fano colouring

Edita Mácajová; Martin Skoviera

2005-01-01

338

Perioperative and clinical-angiographic late outcome of total arterial myocardial revascularization according to different composite original graft techniques.  

PubMed

Total arterial myocardial revascularization (TAMR) is advisable because of the excellent long-term patency of arterial conduits. We present early and midterm outcomes of five different surgical configurations for TAMR. Between January 1998 and May 2004, 112 patients (aged 56.5 +/- 4.5 years, 20% female) with three-vessel disease underwent TAMR. The internal mammary arteries (IMAs) were harvested in a sketelonized fashion. The surgical techniques for TAMR consisted in Y or T composite grafts (n = 88, 78%) constructed between the in situ right IMA (RIMA) and the free left IMA (LIMA) graft (n = 58) or the radial artery (n = 30) (RA) in three different configurations. The other techniques consisted in T- and inverted T-graft (n = 24, 22%) constructed between the RA conduit and the free LIMA graft in two different configurations. The mean follow-up time was 40 +/- 23 months. Postoperative angiographic control was performed in 76/111 (70%) patients. Overall, 472 arterial anastomoses (average 4.2 per patient) were performed. One (0.9%) patient, undergoing the inverted T-graft technique, died on postoperative day 2. Another patient (0.9%), undergoing the lambda-graft technique using both IMAs and RA, suffered a new myocardial infarction probably due to RA conduit vasospasm. One week after surgery, after the transthoracic echocardiographic Doppler with adenosine provocative test, the coronary flow reserve (CFR) at the LIMA and RIMA main stems were 2 +/- 0.4 and 2.4 +/- 0.3, respectively. At 12-month follow-up, after adenosine provocative test, the CFRs at the LIMA and RIMA stems were significantly higher than the values at 1 week after surgery within the same group; (LIMA)CFR (1 week) 2.4 +/- 0.3 (12 months) vs 2 +/- 04 (1 week), P = 0.002; (RIMA)CFR 2.58 +/- 0.4 vs 2.4 +/- 0.3, P = 0.001. The CFR at the RIMA main stem was higher in all measurements within the same group than in the LIMA main stem, but not significantly. In one patient undergoing the lambda-graft technique using both IMAs, the RIMA was found to have a string sign. Postoperative angiography in 50 patients showed that the patency rate for the LIMA was 100%, for the RIMA 97.3%, and for the RA 96.7%. Angiography at 3-year follow-up in 76 patients documented excellent patency rates of the LIMA (97.4%), RIMA (95%), and RA (87%). Survival at 7 years was 92.5%, event-free survival 89.3%, and freedom from angina 94%. Total arterial myocardial revascularization using different surgical configurations is safe and effective. The use of composite arterial grafts provides excellent clinical and angiographic results, with a low rate of angina recurrence and late cardiac events. These configurations allow for complete arterial revascularization. PMID:16550306

Bonacchi, Massimo; Prifti, Edvin; Maiani, Massimo; Frati, Giacomo; Giunti, Gabriele; Di Eusanio, Marco; Di Eusanio, Giuseppe; Leacche, Marzia

2006-03-01

339

Lack of uniformity in colour matching.  

PubMed Central

1. The fraction of red in a red--green mixture matched to yellow increased as the intensities of the match constituents were increased sufficiently to bleach appreciable chlorolabe and erythrolabe. 2. All changes in matching found for a given normal trichromat, (i) with increase in the intensities of the matching components, (ii) as a function of time after the onset of very intense components, (iii) with change in the pupil region through which light enters the eye, and (iv) with change in the region of the retina under test, are consistent with the assumption that matching depends upon the absorption of light in three kinds of (individually colour blind) cones, each with its own visual pigment, provided that the lambda max densities of the latter can vary in the range 0.25--1.0 (common logarithmic units) depending upon the subject. 3. Individual differences in matching among normal (as well as among both varieties of red--green anomalous) trichromats, on the other hand, suggest that the extinction spectra of the cone pigments sensitive to long and medium wave lengths may differ from one trichromat to the next. PMID:313984

Alpern, M

1979-01-01

340

Colour as an Environmental Cue when Learning a Route in a Virtual Environment: Typical and Atypical Development  

ERIC Educational Resources Information Center

Typically developing (TD) 6-year-olds and 9-year-olds, and older children and adults with Williams syndrome (WS) navigated through brick-wall mazes in a virtual environment. Participants were shown a route through three mazes, each with 6 turns. In each maze the floor of each path section was a different colour such that colour acted as an…

Farran, Emily K.; Courbois, Yannick; Van Herwegen, Jo; Cruickshank, Alice G.; Blades, Mark

2012-01-01

341

How the salamander got his spots: the genetics of colour, shape, and local adaptation in European salamanders  

E-print Network

observed in natural populations. In this project the student will use European salamanders as a model salamanders, some subspecies differ quite dramatically in colouration, including some populations having lostHow the salamander got his spots: the genetics of colour, shape, and local adaptation in European

Guo, Zaoyang

342

Investigating of Memory - Colours of Intellectually Disabled Children and Virtual Game Addict Students  

NASA Astrophysics Data System (ADS)

We describe an investigation of memory colours. For this investigation Flash test software was developed. 75 observers used this test software in 4 groups: average elementary school children (aged: 8-9 years), intellectually disabled children (age: 9-15), virtual game addict university students (average age: 20) and university students who play with VR games rarely or never (average age: 20). In this pilot test we investigated the difference of memory colours of these 4 groups.

Sik Lányi, Cecília

343

Two-colour free electron laser with wide frequency separation using a single monoenergetic electron beam  

NASA Astrophysics Data System (ADS)

Studies of a broad bandwidth, two-colour free electron laser (FEL) amplifier using one monoenergetic electron beam are presented. The two-colour FEL interaction is achieved using a series of undulator modules alternately tuned to two well-separated resonant frequencies. Using the broad bandwidth FEL simulation code Puffin, the electron beam is shown to bunch strongly and simultaneously at the two resonant frequencies. Electron bunching components are also generated at the sum and difference of the resonant frequencies.

Campbell, L. T.; McNeil, B. W. J.; Reiche, S.

2014-10-01

344

Two-Colour Free Electron Laser with Wide Frequency Separation using a Single Monoenergetic Electron Beam  

E-print Network

Studies of a broad bandwidth, two-colour FEL amplifier using one monoenergetic electron beam are presented. The two-colour FEL interaction is achieved using a series of undulator modules alternately tuned to two well-separated resonant frequencies. Using the broad bandwidth FEL simulation code Puffin, the electron beam is shown to bunch strongly and simultaneously at the two resonant frequencies. Electron bunching components are also generated at the sum and difference of the resonant frequencies.

Campbell, L T; Reiche, S

2014-01-01

345

“We Are Multiculturalism”: A Self-study of Faculty of Colour With Pre-service Teachers of Colour  

Microsoft Academic Search

This paper reports a self-study of three faculty of colour engaged in teaching a special summer session geared to recruiting people of colour to teaching. Given our past experiences in institutions of higher education, we recognised the unique situation and potential of faculty of colour teaching a class made up almost exclusively of students of colour. We analysed our own

Patricia Prado-Olmos; Francisco Ríos; Lillian Vega Castañeda

2007-01-01

346

A Handheld LED Coloured-Light Mixer for Students to Learn Collaboratively the Primary Colours of Light  

ERIC Educational Resources Information Center

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…

Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Panijpan, Bhinyo

2009-01-01

347

Flower colour and cytochromes P450†  

PubMed Central

Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 3?-hydroxylase (F3?H) and flavonoid 3?,5?-hydroxylase (F3?5?H) and thus they play a crucial role in the determination of flower colour. F3?H and F3?5?H mostly belong to CYP75B and CYP75A, respectively, except for the F3?5?Hs in Compositae that were derived from gene duplication of CYP75B and neofunctionalization. Roses and carnations lack blue/violet flower colours owing to the deficiency of F3?5?H and therefore lack the B-ring-trihydroxylated anthocyanins based upon delphinidin. Successful redirection of the anthocyanin biosynthesis pathway to delphinidin was achieved by expressing F3?5?H coding regions resulting in carnations and roses with novel blue hues that have been commercialized. Suppression of F3?5?H and F3?H in delphinidin-producing plants reduced the number of hydroxyl groups on the anthocyanidin B-ring resulting in the production of monohydroxylated anthocyanins based on pelargonidin with a shift in flower colour to orange/red. Pelargonidin biosynthesis is enhanced by additional expression of a dihydroflavonol 4-reductase that can use the monohydroxylated dihydrokaempferol (the pelargonidin precursor). Flavone synthase II (FNSII)-catalysing flavone biosynthesis from flavanones is also a P450 (CYP93B) and contributes to flower colour, because flavones act as co-pigments to anthocyanins and can cause blueing and darkening of colour. However, transgenic plants expression of a FNSII gene yielded paler flowers owing to a reduction of anthocyanins because flavanones are precursors of anthocyanins and flavones. PMID:23297355

Tanaka, Yoshikazu; Brugliera, Filippa

2013-01-01

348

Structural colour and iridescence in plants: the poorly studied relations of pigment colour  

PubMed Central

Background Colour is a consequence of the optical properties of an object and the visual system of the animal perceiving it. Colour is produced through chemical and structural means, but structural colour has been relatively poorly studied in plants. Scope This Botanical Briefing describes the mechanisms by which structures can produce colour. In plants, as in animals, the most common mechanisms are multilayers and diffraction gratings. The functions of structural colour are then discussed. In animals, these colours act primarily as signals between members of the same species, although they can also play roles in camouflaging animals from their predators. In plants, multilayers are found predominantly in shade-plant leaves, suggesting a role either in photoprotection or in optimizing capture of photosynthetically active light. Diffraction gratings may be a surprisingly common feature of petals, and recent work has shown that they can be used by bees as cues to identify rewarding flowers. Conclusions Structural colour may be surprisingly frequent in the plant kingdom, playing important roles alongside pigment colour. Much remains to be discovered about its distribution, development and function. PMID:20142263

Glover, Beverley J.; Whitney, Heather M.

2010-01-01

349

Anim. Behav., 1997, 53, 10431052 Innate colour preferences and flexible colour learning in the  

E-print Network

interactions between flowering plants and their pollinators are the result of a long coevolutionary history, and the evolutionary history of their relationships, it is necessary to understand the sensory and behavioural colours with sugar rewards. Colour vision is an important component of intra- and inter

Weiss, Martha R.

350

Organic and total mercury in muscle tissue of five aquatic birds with different feeding habits from the SE Gulf of California, Mexico  

Microsoft Academic Search

We measured organic and total Hg in muscle tissue of five species of aquatic birds from the south-eastern gulf of California region, Mexico. Concentrations of total and organic Hg measured in Pelecanus occidentalis were the highest (2.85 and 2.68?gg?1); lowest values of organic Hg (0.20?gg?1) and total Hg (0.47?gg?1) were detected in Anas discors and Anas clypeata, respectively. Differences of

J. Ruelas-Inzunza; J. Hernández-Osuna; F. Páez-Osuna

2009-01-01

351

Effect of fining on the colour and pigment composition of young red wines.  

PubMed

This work aimed to evaluate the effect of four fining agents on the colour and pigment composition of red wines of Tannat. The wines were analysed 15 days after fining and immediately after separation of sediments and bottling. Colour was evaluated by spectrophotometry and polyphenols were analysed by spectrophotometry and HPLC-DAD. The colour intensity of wine was significantly decreased by bentonite and egg albumin. The most remarkable effects on wine phenolic composition were produced by bentonite and gelatin, which significantly decreased anthocyanin and tannin concentrations, respectively. Results show that each fining agent has very different impact on the wine attributes, and their effects depended as well on the composition of the clarified wine. The use of non-traditional agents of fining, as vegetable proteins, may have less impact on the colour and anthocyanin content of red wines. PMID:24679795

González-Neves, Gustavo; Favre, Guzmán; Gil, Graciela

2014-08-15

352

The missing UV opacity and the colours of solar-type stars  

NASA Astrophysics Data System (ADS)

A simple method is proposed to take into account the "missing UV opacity" in solar-type stars. It is shown that the mere inclusion of that UV opacity through a very simple formula is sufficient to bring the theoretical colours in agreement with observed ones for stars of different metal abundances and belonging to the spectral range from mid-F to late-G. Synthetic colours computed in the Geneva and UBV systems reproduce the various observed relations satisfactorily. The relations based on these colours allow reliable estimates of effective temperatures, surface gravities and metal abundances of stars. In addition, solar colours are obtained and three more solar twin candidates are proposed.

Magain, P.

1983-06-01

353

Colour cues proved to be more informative for dogs than brightness  

PubMed Central

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. PMID:23864600

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

2013-01-01

354

Presence of Maillard products in Spanish muffins and evaluation of colour and antioxidant potential.  

PubMed

Spanish muffins are bakery products widely consumed in Spain. During their elaboration process MRPs are formed, being partially responsible for muffin characteristics including their antioxidant capacity. The main aim of the study was evaluating the amount, colour and antioxidant capacity of different fractions of MRPs (low and high molecular weight) isolated from commercial muffins. The fraction of high molecular weight (melanoidins) showed to have a higher antioxidant capacity, measured by ABTS and FRAP, than LMW ones. Significant and relatively close correlations between colour parameters and antioxidant capacity were observed for global MRPs, but only occasionally when isolated fractions of melanoidins and LMW were studied. As summary, it can be said that global MRPs present in muffins, apart from contributing to colour and flavour, can also contribute significantly to muffin conservation, due to their appreciable antioxidant capacity, which seems to be directly correlated with of their colour, although this fact is not extrapolated to isolated fractions of melanoidins and LMW MRPs. PMID:19733614

González-Mateo, S; González-Sanjosé, M L; Muñiz, P

2009-11-01

355

Performance of High Producing Dairy Cows with Three Different Feeding Systems Combining Pasture and Total Mixed Rations  

Microsoft Academic Search

Forty-five Holsteins cows in early to mid lactation wereusedtocomparethreefeedingsystemscombining pasture and total mixed rations (TMR) on animal per- formance in a 21-wk repeated-measures experiment. The three treatments were: 1) pasture plus concen- trate (PC), 2) pasture plus partial TMR (pTMR), and 3) TMR (non-pasture). Total dry matter intake, using chromic oxide as a marker, was 21.6, 25.2, and 26.7 kg\\/d

F. Bargo; L. D. Muller; J. E. Delahoy; T. W. Cassidy

2002-01-01

356

Colour matching of composite resin cements with their corresponding try-in pastes.  

PubMed

Two shades of four resin cements (Calibra, Clearfil Esthetic, Insure, Variolink II), in light- and dual-curing modes, were tested for colour matching with their corresponding try-in pastes, immediately after photopolymerization and after 24-hour dry and dark storage. Colour measurements were performed for 0.8 mm-thick specimens through a 0.8mm-thick ceramic plate. For each resin cement, colour differences (deltaE) were calculated between the two curing modes, and between the corresponding try-in paste, at baseline and after 24h. deltaE>0 values were detected between all resin cements and their try-in pastes, which were brand/shade/curing mode depended. The try-in pastes of the Variolink II system demonstrated the best colour matching (deltaE<2). Try-in pastes of Calibra and Insure, at both curing modes, did not match at an acceptable value, the shade of their corresponding resin cements (deltaE>3.3). Calibra presented the highest colour differences. deltaE values of the Clearfil Esthetic system immediately after photo-activation ranged between 2 and 3 units. A ceramic restoration may fail aesthetically as a result of not acceptable colour match (deltaE>3.3) between the shade of certain resin cements and their relevant try-in pastes. PMID:25134367

Kampouropoulos, D; Gaintantzopoulou, M; Papazoglou, E; Kakaboura, A

2014-06-01

357

The development of responses to novel-coloured objects in male and female domestic chicks.  

PubMed

Male and female domestic chicks were trained to peck on a small coloured (red or green) box for food reinforcement. They were then presented with one box identical to that used during training (familiar) and one of a different colour (unfamiliar) and their preferences were assessed in a simultaneous free choice test. The novel colour was green in chicks trained with a red box and red in chicks trained with a green box. Chicks showed marked variations in their preferences for familiarity and novelty as a function of age and sex. In chicks trained with a green box preferences for the familiar colour were stronger in females than in males at all ages of test. A similar sex difference was observed in chicks trained with a red box, except that at around day 9, when males showed temporarily stronger preferences for familiarity than females. When comparing males and females of red-trained chicks to those of green-trained chicks, a shift in colour prefernce, from red to green, was apparent from day 9 in both sexes, though temporarily stronger in females than in males. Levels of preference for the familiar object showed a peak (centred at around day 5/6) and two dips (centred at around day 4/5 and day 10/11) in both sexes irrespective of colour. Results are discussed in relation to current evidence for simultaneous changes in the brain and in the behaviour of young chicks during development. PMID:24924935

Vallortigara, G; Regolin, L; Zanforlin, M

1994-04-01

358

Investigating ageing methods of Large Magellanic Cloud star clusters using integrated colours  

NASA Astrophysics Data System (ADS)

We present an investigation of 84 star clusters in the Large Magellanic Cloud (LMC) galaxy using different broad-band photometric, age-estimation methods. Because of its intermediate distance, the LMC is uniquely positioned to compare its clusters that have previously been aged using both resolved photometry [colour-magnitude diagrams (CMDs)] of the constituent stars and unresolved methods (integrated, broad-band colour photometry). In our comparison between the published CMD ages to three similar, but different methods based on UBV integrated colours, we find poor matches. We attribute this primarily to two things. First, the UBV integrated broad-band ageing methods require matching a cluster with an expected model prediction of the cluster colours as a function of age. The biggest problem we find is that the stellar clusters in our sample do not typically lie on the model line based on their known age and extinction. That is to say, real cluster colours often do not match the model colours and can be found some distance from expected model values. The second issue, which has been previously documented in numerous studies, is the strong degeneracy between age and extinction in the UBV plane. Certainly, providing more photometric bands will reduce degeneracy between age and reddening. Better yet, if extinction can be independently determined, we show that ages from methods based on integrated colours will more closely match those obtained from CMD ages. However, the underlying issue remains. Simple stellar population models often do not accurately represent the colours of real stellar clusters due to the incomplete and stochastic sampling of the stellar mass function in low- and moderate-mass stellar clusters.

Asa'd, Randa S.; Hanson, M. M.

2012-01-01

359

Geometric and Colour Data Fusion for Outdoor 3D Models  

PubMed Central

This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may be inefficient if the scene is digitalized under unsuitable technical (specific scanner on-board camera) and environmental (rain, dampness, changing illumination) conditions. We address our research towards the integration of images and range data to produce photorealistic models. Our proposal is based on decoupling the colour integration and geometry reconstruction stages, making them independent and controlled processes. This issue is approached from two different viewpoints. On the one hand, given a complete model (geometry plus texture), we propose a method to modify the original texture provided by the scanner on-board camera with the colour information extracted from external images taken at given moments and under specific environmental conditions. On the other hand, we propose an algorithm to directly assign external images onto the complete geometric model, thus avoiding tedious on-line calibration processes. We present the work conducted on two large Roman archaeological sites dating from the first century A.D., namely, the Theatre of Segobriga and the Fori Porticus of Emerita Augusta, both in Spain. The results obtained demonstrate that our approach could be useful in the digitalization and 3D modelling fields. PMID:22969327

Merchan, Pilar; Adan, Antonio; Salamanca, Santiago; Dominguez, Vicente; Chacon, Ricardo

2012-01-01

360

Segregated Optical-NIR colour distributions of MDS galaxies  

E-print Network

We present a K survey of 29 fields covering approximately 90 arcmin^2 from the Medium Deep Survey (MDS) catalogue down to a completeness magnitude of K=18.0 (limiting magnitude K=19.0). The morphology obtained by the MDS team using high resolution images from HST/WFPC2 along with our NIR observations allow a Colour-Magnitude and Colour-Colour analysis that agrees in general with spectral evolution models (Bruzual & Charlot 1998) especially if a reasonable range of metallicities for the Simple Stellar Populations used (0.2 signal the existence of non-negligible star formation in ellipticals and bulges at medium redshift. A number counts calculation for different morphological types show disks become the dominant population at faint magnitudes. The median redshift of the sample is z~0.2, from a photometric redshift estimation using V-K and I-K. A search for EROs in the survey field was also performed, with no detection of objects having I-K > 4.5, setting an upper limit to the number density of EROs at dn_{EROs}/d\\Omega < 0.011 arcmin^{-2} (K < 18.0).

I. Ferreras; L. Cayon; E. Martinez-Gonzalez; N. Benitez; .

1998-10-14

361

Colour polymorphism and correlated characters: genetic mechanisms and evolution.  

PubMed

Colour polymorphisms (CP's) continue to be of interest to evolutionary biologists because of their general tractability, importance in studies of selection and potential role in speciation. Since some of the earliest studies of CP, it has been evident that alternative colour morphs often differ in features other than colour. Here we review the rapidly accumulating evidence concerning the genetic mechanisms underlying correlations between CP and other traits in animals. We find that evidence for genetic correlations is now available for taxonomically diverse systems and that physical linkage and regulatory mechanisms including transcription factors, cis-regulatory elements, and hormone systems provide pathways for the ready accumulation or modification of these correlations. Moreover, physical linkage and regulatory mechanisms may both contribute to genetic correlation in some of the best-studied systems. These results raise the possibility that negative frequency-dependent selection and disruptive selection might often be acting on suites of traits and that the cumulative effects of such selection, as well as correlational selection, may be important to CP persistence and evolution. We consider additional evolutionary implications. We recommend continued efforts to elucidate the mechanisms underlying CP-correlated characters and the more frequent application of comparative approaches, looking at related species that vary in character correlations and patterns of selection. We also recommend efforts to elucidate how frequency-dependent selection may act on suites of characters. PMID:21040047

McKinnon, Jeffrey S; Pierotti, Michele E R

2010-12-01

362

Observation of even-parity autoionization states of uranium by three-colour photoionization optogalvanic spectroscopy in U-Ne hollow cathode discharges  

NASA Astrophysics Data System (ADS)

Three-colour three-step photoionization spectroscopy of uranium has been performed in a U-Ne hollow cathode discharge tube by temporally resolving three-colour photoionization optogalvanic (PIOG) signal from the normal optogalvanic (OG) signal using three tunable pulsed dye lasers. U-Ne hollow cathode discharge tube has been used as a source of uranium atomic vapours and photoionization detector. Using this technique, photoionization spectra of uranium have been investigated systematically in the energy region 52,150-52,590cm-1, through three different excitation pathways, originating from its ground state, 0cm-1(5Lo6). By analysing the three-colour photoionization spectra sixty new even-parity autoionization resonances of uranium have been identified and their probable total angular momentum (J) values have been assigned according to the J-momentum selection rule. The J-value of five autoionization resonances, which have been observed either through all three excitation pathways or through two different excitation pathways where J-value of the second excited levels differs by two, has been assigned uniquely.

Mandal, P. K.; Seema, A. U.; Das, R. C.; Shah, M. L.; Dev, Vas; Suri, B. M.

2013-07-01

363

Colour preferences in nest-building zebra finches.  

PubMed

Some bird species are selective in the materials they choose for nest building, preferring, for example, materials of one colour to others. However, in many cases the cause of these preferences is not clear. One of those species is the zebra finch, which exhibits strong preferences for particular colours of nest material. In an attempt to determine why these birds strongly prefer one colour of material over another, we compared the preferences of paired male zebra finches for nest material colour with their preferences for food of the same colours. We found that birds did indeed prefer particular colours of nest material (in most cases blue) but that they did not generally prefer food of one colour over the other colours. It appears, then, that a preference for one colour or another of nest material is specific to the nest-building context. This article is part of a Special Issue entitled: insert SI title. PMID:23860278

Muth, Felicity; Steele, Matthew; Healy, Susan D

2013-10-01

364

Multi-colour detection of gravitational arcs  

NASA Astrophysics Data System (ADS)

Strong gravitational lensing provides fundamental insights into the understanding of the dark matter distribution in massive galaxies, galaxy clusters, and the background cosmology. Despite their importance, few gravitational arcs have been discovered so far. The urge for more complete, large samples and unbiased methods of selecting candidates increases. Several methods for the automatic detection of arcs have been proposed in the literature, but large amounts of spurious detections retrieved by these methods force observers to visually inspect thousands of candidates per square degree to clean the samples. This approach is largely subjective and requires a huge amount of checking by eye, especially considering the actual and upcoming wide-field surveys, which will cover thousands of square degrees. In this paper we study the statistical properties of the colours of gravitational arcs detected in the 37 deg2 of the CFHTLS-Archive-Research Survey (CARS). Most of them lie in a relatively small region of the (g' - r', r' - i') colour-colour diagram. To explain this property, we provide a model that includes the lensing optical depth expected in a ?CDM cosmology that, in combination with the sources' redshift distribution of a given survey, in our case CARS, peaks for sources at redshift z ~ 1. By furthermore modelling the colours derived from the spectral energy distribution of the galaxies that dominate the population at that redshift, the model reproduces the observed colours well. By taking advantage of the colour selection suggested by both data and model, we automatically detected 24 objects out of 90 detected by eye checking. Compared with the single-band arcfinder, this multi-band filtering returns a sample complete to 83% and a contamination reduced by a factor of ~6.5. New gravitational arc candidates are also proposed.

Maturi, Matteo; Mizera, Sebastian; Seidel, Gregor

2014-07-01

365

The nature of the Sloan Digital Sky Survey galaxies in various classes based on morphology, colour and spectral features - II. Multi-wavelength properties  

NASA Astrophysics Data System (ADS)

We present a multi-wavelength study of the nature of the Sloan Digital Sky Survey (SDSS) galaxies divided into fine classes based on their morphology, colour and spectral features. The SDSS galaxies are classified into early-type and late-type; red and blue; passive, HII, Seyfert and low-ionization nuclear emission region, which returns a total of 16 fine classes of galaxies. The properties of galaxies in each fine class are investigated from radio to X-ray, using the Two-Micron All-Sky Survey, Infrared Astronomical Satellite, Faint Images of the Radio Sky at Twenty-centimetres, NRAO VLA Sky Survey, Galaxy Evolution Explorer and Roentgen Satellite data. The UV-optical-NIR colours of blue early-type galaxies (BEGs) seem to result from the combination of old stellar population and recent star formation (SF), if there is no significant difference in their formation epoch between different spectral classes. Non-passive red early-type galaxies (REGs) have larger metallicity and younger age than passive REGs, considering their UV-optical-NIR colours, which imply that non-passive REGs have suffered recent SF adding young and metal-rich stars to them. The radio-detection fraction of REGs strongly depends on their optical absolute magnitudes, while that of most late-type galaxies does not, implying the difference in their radio sources: active galactic nucleus and SF. The optical-NIR colours of red late-type galaxies (RLGs) reveal that they may have considerable old stars as well as young stars. The UV-optical colours and the radio-detection fraction of passive RLGs show that they have properties similar to REGs rather than non-passive RLGs. Dust extinction may not be a dominant factor making RLGs red, because RLGs are detected in the mid- and far-infrared bands less efficiently than blue late-type galaxies (BLGs). The passive BLGs have very blue UV-optical-NIR colours, implying either recent SF quenching or current SF in their outskirts. Including the star formation rate, other multi-wavelength properties in each fine class are investigated and their implication on the identity of each fine class is discussed.

Lee, Joon Hyeop; Lee, Myung Gyoon; Park, Changbom; Choi, Yun-Young

2010-01-01

366

Principal components colour display of ERTS imagery  

NASA Technical Reports Server (NTRS)

In the technique presented, colours are not derived from single bands, but rather from independent linear combinations of the bands. Using a simple model of the processing done by the visual system, three informationally independent linear combinations of the four ERTS bands are mapped onto the three visual colour dimensions of brightness, redness-greenness and blueness-yellowness. The technique permits user-specific transformations which enhance particular features, but this is not usually needed, since a single transformation provides a picture which conveys much of the information implicit in the ERTS data. Examples of experimental vector images with matched individual band images are shown.

Taylor, M. M.

1974-01-01

367

Imagery, colour and illness: a review.  

PubMed

This paper reviews research on the role of colour and imagery in relation to illness and examines how this might improve communication between the sufferer and those treating or caring for them. It describes a method by which colour can be related to situations such as an individual's mood and how this might be used to predict response to treatment. Furthermore, it provides evidence that documenting the imagery of an illness might give insight into the patients' fears and concerns about their condition as well as helping non-sufferers to understand what they are going through. PMID:22023001

Carruthers, Helen R

2011-09-01

368

Exploring iris colour prediction and ancestry inference in admixed populations of South America.  

PubMed

New DNA-based predictive tests for physical characteristics and inference of ancestry are highly informative tools that are being increasingly used in forensic genetic analysis. Two eye colour prediction models: a Bayesian classifier - Snipper and a multinomial logistic regression (MLR) system for the Irisplex assay, have been described for the analysis of unadmixed European populations. Since multiple SNPs in combination contribute in varying degrees to eye colour predictability in Europeans, it is likely that these predictive tests will perform in different ways amongst admixed populations that have European co-ancestry, compared to unadmixed Europeans. In this study we examined 99 individuals from two admixed South American populations comparing eye colour versus ancestry in order to reveal a direct correlation of light eye colour phenotypes with European co-ancestry in admixed individuals. Additionally, eye colour prediction following six prediction models, using varying numbers of SNPs and based on Snipper and MLR, were applied to the study populations. Furthermore, patterns of eye colour prediction have been inferred for a set of publicly available admixed and globally distributed populations from the HGDP-CEPH panel and 1000 Genomes databases with a special emphasis on admixed American populations similar to those of the study samples. PMID:25051225

Freire-Aradas, A; Ruiz, Y; Phillips, C; Maroñas, O; Söchtig, J; Tato, A Gómez; Dios, J Álvarez; de Cal, M Casares; Silbiger, V N; Luchessi, A D; Luchessi, A D; Chiurillo, M A; Carracedo, A; Lareu, M V

2014-11-01

369

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

PubMed

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. PMID:23247309

Rothen, Nicolas; Nikoli?, Danko; Jürgens, Uta Maria; Mroczko-W?sowicz, Aleksandra; Cock, Josephine; Meier, Beat

2013-03-01

370

Pretty in pink: The early development of gender-stereotyped colour preferences.  

PubMed

Parents commonly dress their baby girls in pink and their baby boys in blue. Although there is research showing that children prefer the colour blue to other colours (regardless of gender), there is no evidence that girls actually have a special preference for the colour pink. This is the focus of the current investigation. In a large cross-sectional study, children aged 7 months to 5 years were offered eight pairs of objects and asked to choose one. In every pair, one of the objects was always pink. By the age of 2, girls chose pink objects more often than boys did, and by the age of 2.5, they had a significant preference for the colour pink over other colours. At the same time, boys showed an increasing avoidance of pink. These results thus reveal that sex differences in young children's preference for the colour pink involves both an increasing attraction to pink by young girls and a growing avoidance of pink by boys. PMID:21848751

Lobue, Vanessa; Deloache, Judy S

2011-09-01

371

Association between masticatory performance using a colour-changeable chewing gum and jaw movement.  

PubMed

The purpose of this study was to investigate the relationship between masticatory performance as determined using a colour-changeable chewing gum and mandibular movements. Subjects comprised 45 fully dentate adults (23 men, 22 women; mean age, 28·1 years). The gum was chewed for a specified number of chewing strokes (20, 40, 60, 80, 120 or 160 strokes) without any instructions as to chewing side. A colourimeter was used to measure L*, a* and b* values (CIE-L*a*b* colour system) for the chewed gum, then the difference between two colours in the CIE-L*a*b* colour space (?E) for each number of chewing strokes was calculated according to a formula. Index of masticatory performance (?E60) for each subject was obtained using ?E for 20, 40, 60, 80, 120 and 160 strokes. Mandibular movements were recorded using an opto-electric system with six degrees of freedom. Twelve parameters of mandibular movements relating to amplitude, duration, velocity and angle were computed for each cycle, and mean values for 10 cycles (from cycle 11 to 20) were calculated separately. Stepwise multiple regression analysis identified maximum closing velocity and closing angle as predictors accounting for 18% of the variation in ?E60. These results suggest that lower angles of approach to intercuspation and faster speed during closing duration are associated with colour changes in the colour-changeable chewing gum. PMID:21314707

Komagamine, Y; Kanazawa, M; Minakuchi, S; Uchida, T; Sasaki, Y

2011-08-01

372

The Impact of Biochemistry vs. Population Membership on Floral Scent Profiles in Colour Polymorphic Hesperis matronalis  

PubMed Central

Background and Aims Studies of floral scent evolution often attribute variation in floral scent to differences in pollinator behaviour, ignoring the potential for shared biochemistry between floral scent and floral colour to dictate patterns of phenotypic variation in scent production. To determine the relative effects of shared biochemistry and/or localized population-level phenomena on floral scent phenotype, floral scent composition and emission rate were examined in five wild populations of colour polymorphic Hesperis matronalis (Brassicaceae). Methods Floral scent was collected by in situ dynamic headspace extraction on purple and white colour morphs in each of five wild populations. Gas chromatography–mass spectroscopy of extracts allowed determination of floral scent composition and emission rate for all individuals, which were examined by non-metric multidimensional scaling and analysis of variance (ANOVA), respectively, to determine the contributions of floral colour and population membership to scent profile variation. Key Results Despite the fact that colour morph means were very similar in some populations and quite different in other populations, colour morphs within populations did not differ from each other in terms of scent composition or emission rate. Populations differed significantly from one another in terms of both floral scent composition and emission rate. Conclusions Shared biochemistry alone cannot explain the variation in floral scent phenotype found for H. matronalis. Such a result may suggest that the biochemical association between floral scent and floral colour is complex or dependent on genetic background. Floral scent does vary significantly with population membership; several factors, including environmental conditions, founder effects and genetics, may account for this differentiation and should be considered in future studies. PMID:18819948

Majetic, Cassie J.; Raguso, Robert A.; Ashman, Tia-Lynn

2008-01-01

373

Automated image analysis as a tool to quantify the colour and composition of rainbow trout  

E-print Network

Automated image analysis as a tool to quantify the colour and composition of rainbow trout cutlets in rainbow trout. The proposed automated image analysis methods were tested on a total of 983 of trout cutlets. © 2006 Elsevier B.V. All rights reserved. Keywords: Image analysis; Rainbow trout; Cutlet

Manne, Fredrik

374

Total kinetic energy production of body segments is different between racing and training paces in elite Olympic rowers  

Microsoft Academic Search

Total kinetic energy (TKE) was calculated for 28 Canadian national team Olympic rowers during training on water, comparing low-stroke rates (18–22 stroke\\/min) and high-stroke rates (32–40 stroke\\/min), using video analysis. Stroke duration was normalized to 100%, beginning and ending at the “catches”, with the drive phase occurring first and recovery second. Two discrete points were identified during the stroke, both

Daniel J. Bechard; Volker Nolte; Angela E. Kedgley; Thomas R. Jenkyn

2009-01-01

375

pH, alkalinity and total CO 2 in coastal seawater by potentiometric titration with a difference derivative readout  

Microsoft Academic Search

A method for measuring three components of the CO2 system, pH, alkalinity (At) and total CO2 (TCO2) in coastal seawater is presented. The measurements are sufficiently precise to register CO2 changes of biological origin in surficial and coastal waters or in culture media. The method is based on a modified potentiometric titration of seawater with acid in a custom-built cell

J. Mart??n Hernández-Ayón; Stuart L. Belli; Alberto Zirino

1999-01-01

376

Mapping of AFLP markers linked to seed coat colour loci in Brassica juncea (L.) Czern.  

PubMed

Association mapping of the seed-coat colour with amplified fragment length polymorphism (AFLP) markers was carried out in 39 Brassica juncea lines. The lines had genetically diverse parentages and varied for seed-coat colour and other morphological characters. Eleven AFLP primer combinations were used to screen the 39 B. juncea lines, and a total of 335 polymorphic bands were detected. The bands were analysed for association with seed-coat colour using multiple regression analysis. This analysis revealed 15 markers associated with seed-coat colour, obtained with eight AFLP primer combinations. The marker E-ACA/M-CTG(350 )explained 69% of the variation in seed-coat colour. This marker along with markers E-AAC/M-CTC(235 )and E-AAC/M-CTA(250) explained 89% of the total variation. The 15 associated markers were validated for linkage with the seed-coat colour loci using a recombinant inbred line (RIL) mapping population. Bands were amplified with the eight AFLP primer combinations in 54 RIL progenies. Of the 15 associated markers, 11 mapped on two linkage groups. Eight markers were placed on linkage group 1 at a marker density of 6.0 cM, while the remaining three were mapped on linkage group 2 at a marker density of 3.6 cM. Marker E-ACA/M-CTG(350 )co-segregated with Gene1 controlling seed-coat colour; it was specific for yellow seed-coat colour and mapped to linkage group 1. Marker E-AAC/M-CTC(235) (AFLP8), which had been studied previously, was present on linkage group 2; it was specific for brown seed-coat colour. Since AFLP markers are not adapted for large-scale applications in plant breeding, it is important to convert these to sequence-characterised amplified region (SCAR) markers. Marker E-AAC/M-CTC(235) (AFLP8) had been previously converted into a SCAR. Work is in progress to convert the second of the linked markers, E-ACA/M-CTG(350), to a SCAR. The two linked AFLP markers converted to SCARs will be useful for developing yellow-seeded B. juncea lines by means of marker-assisted selection. PMID:15024465

Sabharwal, V; Negi, M S; Banga, S S; Lakshmikumaran, M

2004-06-01

377

Colours of isolated galaxies selected from the Two-Micron All-Sky Survey  

NASA Astrophysics Data System (ADS)

The properties of isolated galaxies are driven mainly by intrinsic evolution and not by the external influence of their environments. Therefore, the sample of isolated galaxies can be considered as a reference sample to study different environmental effects. We have made detailed comparisons between the near-infrared (Two-Micron All-Sky Survey, 2MASS) and optical (Sloan Digital Sky Survey, SDSS) colours of the 2MASS Isolated Galaxies (2MIG) sample selected from the 2MASS Extended Source Catalogue and with other objects from the wide range of denser environments (field, groups/clusters, triplets and pairs). We have found that early-type galaxies show similar (J - H)rest and (g - r)rest colours in practically all types of environments, except for the massive early-type galaxies located in compact pairs with high velocity difference (dV ˜ 180 km s-1), which are significantly redder and brighter than isolated galaxies. We assume that these pairs are located in the centres of more populated groups and clusters. In general, galaxies in groups and pairs of spiral and late morphological types have redder near-infrared colours (J - H)rest than 2MIG isolated galaxies. The (g - r)rest colours of galaxies in groups and pairs with high velocity difference are also significantly redder than the corresponding colours of 2MIG isolated galaxies. In contrast, the members of most compact pairs (dV ˜ 50 km s-1, R ˜ 30 kpc) show the same (g - r)rest colour and even tend to be bluer than 2MIG isolated galaxies. In summary, our results show that the colours of galaxies depend very much on external factors.

Melnyk, O.; Mitronova, S.; Karachentseva, V.

2014-02-01

378

Transcriptome sequencing and metabolite analysis reveals the role of delphinidin metabolism in flower colour in grape hyacinth  

PubMed Central

Grape hyacinth (Muscari) is an important ornamental bulbous plant with an extraordinary blue colour. Muscari armeniacum, whose flowers can be naturally white, provides an opportunity to unravel the complex metabolic networks underlying certain biochemical traits, especially colour. A blue flower cDNA library of M. armeniacum and a white flower library of M. armeniacum f. album were used for transcriptome sequencing. A total of 89 926 uni-transcripts were isolated, 143 of which could be identified as putative homologues of colour-related genes in other species. Based on a comprehensive analysis relating colour compounds to gene expression profiles, the mechanism of colour biosynthesis was studied in M. armeniacum. Furthermore, a new hypothesis explaining the lack of colour phenotype of the grape hyacinth flower is proposed. Alteration of the substrate competition between flavonol synthase (FLS) and dihydroflavonol 4-reductase (DFR) may lead to elimination of blue pigmentation while the multishunt from the limited flux in the cyanidin (Cy) synthesis pathway seems to be the most likely reason for the colour change in the white flowers of M. armeniacum. Moreover, mass sequence data obtained by the deep sequencing of M. armeniacum and its white variant provided a platform for future function and molecular biological research on M. armeniacum. PMID:24790110

Lou, Qian; Liu, Yali; Qi, Yinyan; Jiao, Shuzhen; Tian, Feifei; Jiang, Ling; Wang, Yuejin

2014-01-01

379

How feather colour reflects its carotenoid content  

Microsoft Academic Search

Summary 1. Many birds sequester carotenoid pigments in colourful patches of feathers to advertise or compete for mates. Because carotenoids can be scarce in nature and serve valuable physiological functions, only the highest-quality individuals are thought to acquire or allocate more pigments for use in sexual displays. 2. A critical but rarely tested assumption of carotenoid-based signals is that the

Lauri Saks; Kevin McGraw; Peeter Horak

2003-01-01

380

Dietary tannins improve lamb meat colour stability  

Microsoft Academic Search

Fourteen male Comisana lambs were divided into two groups at 45days of age: lambs fed a concentrate diet (C), or lambs fed the same concentrate with the addition of quebracho (Schinopsis lorentzii) tannins (T). Sheep were slaughtered at 105days of age. Lipid oxidation, colour coordinates, haem pigment concentration, and metmyoglobin percentages were measured on minced semimembranosus muscle (SM) over 14days

G. Luciano; F. J. Monahan; V. Vasta; L. Biondi; M. Lanza; A. Priolo

2009-01-01

381

Genetics of human iris colour and patterns.  

PubMed

The presence of melanin pigment within the iris is responsible for the visual impression of human eye colouration with complex patterns also evident in this tissue, including Fuchs' crypts, nevi, Wolfflin nodules and contraction furrows. The genetic basis underlying the determination and inheritance of these traits has been the subject of debate and research from the very beginning of quantitative trait studies in humans. Although segregation of blue-brown eye colour has been described using a simple Mendelian dominant-recessive gene model this is too simplistic, and a new molecular genetic perspective is needed to fully understand the biological complexities of this process as a polygenic trait. Nevertheless, it has been estimated that 74% of the variance in human eye colour can be explained by one interval on chromosome 15 that contains the OCA2 gene. Fine mapping of this region has identified a single base change rs12913832 T/C within intron 86 of the upstream HERC2 locus that explains almost all of this association with blue-brown eye colour. A model is presented whereby this SNP, serving as a target site for the SWI/SNF family member HLTF, acts as part of a highly evolutionary conserved regulatory element required for OCA2 gene activation through chromatin remodelling. Major candidate genes possibly effecting iris patterns are also discussed, including MITF and PAX6. PMID:19619260

Sturm, Richard A; Larsson, Mats

2009-10-01

382

The cultural origins of colour categories  

E-print Network

? ­ Nativism: genetic makeup. ­ Empiricism: interaction with the environment. ­ Culturalism: culturalThe cultural origins of colour categories Tony Belpaeme Artificial Intelligence Lab Vrije.g. Elman et al., 1996; Yendrikhovskij, 2001) ­ This all happens without the influence of culture

Belpaeme, Tony

383

Shell colouration and parasite tolerance in two helicoid snail species.  

PubMed

The polymorphism of shell colouration in helicoid snails is a well-known phenomenon attributed to different factors such as predation and climatic effects. Another aspect contributing to this polymorphism could be the interplay of melanin production and phenoloxidase-related immunity. Therefore, in this study we aimed at answering the questions whether there is a differential sensitivity of different snail shell colour morphs to nematode infection, and whether this can be related to differences in phenoloxidase (PO) activity levels using the two helicoid, polymorphic snail species Cepaea hortensis and Cernuella virgata. Snails of both species were artificially infected with the parasitic nematode Phasmarhabditis hermaphrodita, and analysed for mortality and PO activity levels. We found C. virgata to be more severely affected by P. hermaphrodita infection than C. hortensis, and the dark C. virgata morphs to be more resistant to lethal effects of this infection than pale morphs. However, these differences in sensitivity to the parasite could not clearly be related to different PO activity levels. PMID:24480673

Scheil, Alexandra E; Hilsmann, Stefanie; Triebskorn, Rita; Köhler, Heinz-R

2014-03-01

384

Organic and total mercury in muscle tissue of five aquatic birds with different feeding habits from the SE Gulf of California, Mexico.  

PubMed

We measured organic and total Hg in muscle tissue of five species of aquatic birds from the south-eastern gulf of California region, Mexico. Concentrations of total and organic Hg measured in Pelecanus occidentalis were the highest (2.85 and 2.68 microgg(-1)); lowest values of organic Hg (0.20 microgg(-1)) and total Hg (0.47 microgg(-1)) were detected in Anas discors and Anas clypeata, respectively. Differences of Hg levels were related to feeding habits, being concentrations in birds of piscivorous habits more elevated than corresponding values in non-piscivorous species. PMID:19419748

Ruelas-Inzunza, J; Hernández-Osuna, J; Páez-Osuna, F

2009-07-01

385

Total mercury distribution in different tissues of six species of freshwater fish from the Kpong hydroelectric reservoir in Ghana.  

PubMed

Total mercury concentrations were determined in seven tissues of 38 fish samples comprising six species from the Kpong hydroelectric reservoir in Ghana by cold vapour atomic absorption spectrometry technique using an automatic mercury analyzer. Mercury concentration in all the tissues ranged from 0.005 to 0.022 ?g/g wet weight. In general, the concentration of mercury in all the tissues were decreasing in the order; liver?>?muscle?>?intestine?>?stomach?>?gonad?>?gill?>?swim bladder. Mercury concentration was generally greater in the tissues of high-trophic-level fish such as Clarotes laticeps, Mormyrops anguilloides and Chrysichthys aurutus whereas low-trophic-level fish such as Oreochromis niloticus recorded low mercury concentration in their tissues. The results obtained for total mercury concentration in the muscle tissues analysed in this study are below the WHO/FAO threshold limit of 0.5 ?g/g. This suggests that the exposure of the general public to Hg through fish consumption can be considered negligible. PMID:21713471

Atta, Alhassan; Voegborlo, Ray Bright; Agorku, Eric Selorm

2012-05-01

386

Advances in methods for colour marking of mosquitoes  

PubMed Central

Background Different techniques are available for colour marking insects and each technique may be suitable for different insect species. Mosquitoes can be marked to determine population size, distribution and flight distance or distinguish closely related species. In this study, two methods of colour marking mosquitoes were described in detail and the impact of both methods on the survival and host-seeking behaviour of the malaria mosquito Anopheles gambiae sensu stricto was investigated. Methods Mosquitoes were marked in groups with fluorescent powder or fluorescent dye. The powder was applied by creating a cloud of powder in a paper cup and the dye was applied with an airbrush. The effect of marking on the survival of mosquitoes of different age groups was tested under controlled conditions. The effect of marking on the host seeking response of the mosquitoes was tested in an olfactometer with human and cow odour as baits. Results No effect of either of the marking methods was found on the survival of mosquitoes that were treated 1 or 3 days after emergence, however, the survival of mosquitoes treated 5 or 9 days after emergence was significantly reduced. The host-seeking response of mosquitoes to human or cow odour was tested in a dual-port olfactometer and was not found to be affected by treatment with fluorescent powder or dye. Conclusions Both methods are suitable for colour marking large groups of mosquitoes. Marking with fluorescent powder, however, is preferred because the method is simpler, visible without a UV light and no specific materials are required. PMID:23835091

2013-01-01

387

Female-specific colouration, carotenoids and reproductive investment in a dichromatic species, the upland goose Chloephaga picta leucoptera  

PubMed Central

Although studies on the evolution and function of female ornaments have become more numerous in the last years, the majority of these studies were carried out in cases where female ornaments were a smaller and duller version of the ornaments found in males. There are substantially fewer studies on species with female-specific ornaments. However, no study so far investigated the potential of female-specific colouration as a quality signal in birds with conventional sex roles. We studied female-specific ornamentation in a strongly sexually dichromatic species, the upland goose Chloephaga picta leucoptera, in two consecutive years. Male upland geese have white head and breast feathers and black legs, whereas females have reddish-brown head and breast feathers and conspicuous yellow-orange legs. We found that female-specific colouration in upland geese can reliably indicate different aspects of female phenotypic quality. Females with more orange coloured legs and more red-like head colours had higher clutch and egg volumes than females with a paler leg and head colouration, and a more reddish plumage colouration was related to a higher body condition. These relationships provide the theoretic possibility for males to assess female phenotypic quality on the basis of colouration. Furthermore, the females with a more orange-like tarsus colouration had higher plasma carotenoid levels. Both tarsus colouration and carotenoid concentrations of individual females were highly correlated across years, indicating that tarsus colour is a stable signal. Despite this correlation, small individual differences in plasma carotenoid concentrations between the two study years were related to differences in tarsus colouration. We thus show for the first time in a wild bird and under natural conditions that carotenoid-based integument colouration remains consistent between individuals in consecutive years and is also a dynamic trait reflecting individual changes in carotenoid levels. In this species, where pairs form life-long bonds, the honesty of the carotenoid-based integument colouration suggests that it may be a sexually selected female ornament that has evolved through male mate choice. Electronic supplementary material The online version of this article (doi:10.1007/s00265-010-0990-4) contains supplementary material, which is available to authorized users. PMID:20976290

Gladbach, David Joachim; Kempenaers, Bart; Quillfeldt, Petra

2010-01-01

388

The nature of sound and vision in relation to colour  

NASA Astrophysics Data System (ADS)

The increasing role of sound within the visual arts context and the trend in postmodernism towards interdisciplinary artworks has demanded a heightened awareness of the audio-visual. This paper explores some of the fundamental physical properties of both sound and colour, their similarities and differences and how the audio and visual senses are related. Ways in which soundscapes have been combined with paintings in exhibitions by the author will be used to illustrate how the two media can be combined to enhance the overall artistic experience.

Greated, Marianne

2011-03-01

389

EXERCISES IN CARTOGRAPHY AND GEOINFORMATICS: TEACHING THE COLOURS Arzu LTEKN  

E-print Network

employ colour as information. In a Remote-Sensing data based forest classification map, the classes production. #12;2. What is Colour 2.1. Definition Colour is light. In other words, it is a side product of the light-spectrum. The light is reflected or absorbed by the objects, and we "see" the reflected ones

�öltekin, Arzu

390

The representation of colours in the cerebral cortex  

Microsoft Academic Search

New insights into how colour is represented in the cerebral cortex and what variables govern the responses of single cortical colour-coded cells have been gained by the discovery of specific visual cortical areas rich in colour-coded cells.

S. Zeki

1980-01-01

391

Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health  

Microsoft Academic Search

Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated,

Ian D. Stephen; Vinet Coetzee; Miriam Law Smith; David I. Perrett; Rebecca Sear

2009-01-01

392

Summing Large-N Towers in Colour Flow Evolution  

E-print Network

We consider soft gluon evolution in the colour flow basis. We give explicit expressions for the colour structure of the (one-loop) soft anomalous dimension matrix for an arbitrary number of partons, and show how the successive exponentiation of classes of large-N contributions can be achieved to provide a systematic expansion of the evolution in terms of colour supressed contributions.

Simon Plätzer

2013-12-09

393

Inheritance of coat colour in the field spaniel dog  

E-print Network

Note Inheritance of coat colour in the field spaniel dog R Robinson St Stephens Nursery, Stephens known as roan. dog genetics / coat colour / field spaniel / breed R�sum� - H�r�dit� de la couleur du for the heredity of coat colour in the dog (Little, 1957; Robinson, 1990), it has become apparent as work

Paris-Sud XI, Université de

394

Towards more adequate colour histograms for in-body images  

Microsoft Academic Search

Although there is a growing number of scientific papers describing classification of in-body images, most of it is based on traditional colour histograms. In this paper we explain why these might not be the most adequate visual features for in-body image classification. Based on a colour dynamic range maximization criterion, we propose a methodology for creating more adequate colour histograms,

A. Sousa; M. Dinis-Ribeiro; M. Areia; M. Correia; M. Coimbra

2008-01-01

395

A NEW PROOF OF THE FOUR-COLOUR THEOREM  

Microsoft Academic Search

The four-colour theorem, that every loopless planar graph admits a vertex-colouring with at most four dierent colours, was proved in 1976 by Appel and Haken, using a computer. Here we announce another proof, still using a computer, but simpler than Appel and Haken's in several respects. For our purposes a graph G consists of a nite set V (G) of

NEIL ROBERTSON; DANIEL P. SANDERS; PAUL SEYMOUR; ROBIN THOMAS

1996-01-01

396

Extending partial 3-colourings in a planar graph  

Microsoft Academic Search

Let D be a disc, and let X be a finite subset of points on the boundary of D. An essential part of the proof of the four colour theorem is the fact that many sets of 4-colourings of X do not arise from the proper 4-colourings of any graph drawn in D. In contrast to this, we show that

Matt Devos; Paul D. Seymour

2003-01-01

397

Four colours suffice: how the map problem was solved  

Microsoft Academic Search

This book contains an account of the history of the Four Colour Problem and its solution. Suppose one wants to assign colours to the countries on a map in such a way that no two neighbouring countries — with a common boundary consisting of more than just isolated points — receive the same colour. (We assume the map is drawn

Robin Wilson; Charles Nash

2003-01-01

398

Rotation sequences and edge-colouring of binary tree pairs  

Microsoft Academic Search

The famous four-colour problem of planar maps is equivalent, by an optimally fast reduction, to the problem of colouring pairs of binary trees (CPBT). Extant proofs of the four colour theorem lack conciseness, are not lucid in their detail and require hours of electronic computation. The search for a more satisfactory proof continues and, in this spirit, we explore one

Alan Gibbons; Paul Sant

2004-01-01

399

The Sylvester-Gallai theorem, colourings and algebra  

Microsoft Academic Search

Our point of departure is the following simple common gen- eralisation of the Sylvester-Gallai theorem and the Motzkin-Rabin the- orem: Let S be a finite set of points in the plane, with each point coloured red or blue or with both colours. Suppose that for any two distinct points A, B 2 S sharing a colour there is a third

Lourens M. Pretorius; Konrad J. Swanepoel

2009-01-01

400

THE EFFECTIVENESS OF COLOUR IN LEARNING FROM EDUCATIONAL TELEVISION  

Microsoft Academic Search

The author reviews recent research comparing both the relative learning gains and relative attitudes of students using colour or monochrome television material. It is concluded that all users of educational television should resist the temptation to spend large sums on colour television equipment merely because colour is now widely preferred by society at large.

Geoffrey Roberts

1978-01-01

401

Visual pattern based colour image compression G. Schaefer+  

E-print Network

& Imaging Institute ++ School of Computing & Mathematics University of Derby, UK ABSTRACT A novel colour of predefined, universal visual patterns in a uniform colour space. Source coding and colour quantisation per pixel) needed to represent a digital image whilst trying to maintain high perceptual image quality

Aickelin, Uwe

402

Assessment of fire damaged concrete using colour image analysis  

Microsoft Academic Search

Assessment of fire damaged concrete structures usually starts with visual observation of colour change, cracking and spalling. On heating, a change in colour from normal to a pink\\/red is often observed and this is useful since it coincides with the onset of significant loss of concrete strength. Optical microscopy combined with colour image analysis has been used to quantify changes

N. R Short; J. A Purkiss; S. E Guise

2001-01-01

403

Radiobiological basis of total body irradiation with different dose rate and fractionation: repair capacity of hemopoietic cells  

SciTech Connect

Total body irradiation (TBI) followed by bone marrow transplantation is being used in the treatment of malignant or non-malignant hemopoietic disorders. It has been believed that the ability of hemopoietic cells to repair sublethal radiation damage is negligible. Therefore, several schools of investigators suggested that TBI in a single exposure at extremely low dose rate (5 rad/min) over several hours, or in several fractions in 2-3 days, should yield a higher therapeutic gain, as compared with a single exposure at a high dose rate (26 rad/min). We reviewed the existing data in the literature, in particular, the response of hemopoietic cells to fractionated doses of irradiation and found that the repair capacity of both malignant and non-malignant hemopoietic cells might be greater than has been thought. It is concluded that we should not underestimate the ability of hemopoietic cells to repair sublethal radiation damage in using TBI.

Song, C.W.; Kim, T.H.; Khan, F.M.; Kersey, J.H.; Levitt, S.H.

1981-12-01

404

Radiobiological modeling of combined targeted [sup 131]I therapy and total body irradiation for treatment of disseminated tumors of differing radiosensitivity  

SciTech Connect

A model is presented for calculating combinations of targeted [sup 131]I and total body irradiation, followed by bone marrow rescue, in the treatment of tumors of different radiosensitivity. The model is used to evaluate the role of the total body irradiation component in the optimal combination regime as a function of the radiosensitivity of the tumor cells. A microdosimetric model was used to calculate absorbed dose in small tumors and micrometastases when uniformly targeted by the radionuclide [sup 131]I. Cell kill was calculated from absorbed dose using an extended version of the linear quadratic model. The addition of varying total doses of total body irradiation, assuming 2 Gy fractions, was also calculated using the linear quadratic model. The net cell kill from combined modality (targeted [sup 131]I and total body irradiation) was computed for varying proportions of the two components, for a range of tumor sizes, restricting the total radiation dose to within tolerance for a full-course TBI regime ([approximately] 14 Gy total) in all cases. The calculations were repeated for a range of presumed tumor uptakes of the targeting agent and for a range of tumor radiosensitivities, typical of those reported for tumor cells of differing type in culture. Optimal regimes were identified as those predicted to yield a high probable tumor cure rate (evaluated using a Poisson statistical model) for all tumor sizes. The analysis supports earlier model studies which predicted that systemic combination treatment with targeted [sup 131]I and total body irradiation would be superior to either component used alone. The intrinsic tumor radiosensitivity is found to be a factor which influences the optimal combination of the [sup 131]I and external beam total body irradiation components. 20 refs., 8 figs., 3 tabs.

Amin, A.E.; Wheldon, T.E.; O'Donoghue, J.A.; Barrett, A. (Univ. of Glasgow (United Kingdom))

1993-09-20

405

The calculation of small molecular interactions by the differences of separate total energies. Some procedures with reduced errors  

Microsoft Academic Search

A new direct difference method for the computation of molecular interactions has been based on a bivariational transcorrelated treatment, together with special methods for the balancing of other errors. It appears that these new features can give a strong reduction in the error of the interaction energy, and they seem to be particularly suitable for computations in the important region

S. F. Boys; F. Bernardi

1970-01-01

406

Wine: does the colour count?  

Microsoft Academic Search

The objective of this study was to determine whether phenolic constituents present in red wine and grape juice modulate plasma lipid and lipoprotein concentrations in healthy human subjects. All subjects consumed in random order 375 ml of red or white wine per day or 500 ml of two different grape juices (high and low phenols) per day for periods of

David M. Goldberg; Vesna Garovic-Kocic; Eleftherios P. Diamandis; Cecil R. Pace-Asciak

1996-01-01

407

Scent and Colour in Flowers  

Microsoft Academic Search

THE extension of our perceptive faculties of sight and hearing by various optical and acoustical instruments may enable us to comprehend the possibility of these faculties existing in other creatures to a degree so far surpassing ours as to seem a difference almost of kind. So the sight of the vulture would seem to be paralleled by the faculty of

G. S. Boulger

1878-01-01

408

Bluer colour of UX Arietis at fainter visual magnitudes  

NASA Astrophysics Data System (ADS)

Aims:The RS CVn star UX Ari appears bluer when it is fainter, which is unusual for a spotted star; we aim to resolve this unusual behaviour of the object. Also the data available in the literature indicate that the mean V magnitude of UX Ari varies by about 25 years; we want to confirm whether this is indeed true. Methods: The most important parameter in understanding the colour variation is the relative brightnesses of the component stars of UX Ari. We use all spectroscopic information available in the literature to obtain a reasonable value for this parameter. We also present new BV photometry of UX Ari obtained on 58 nights during 2001-07. Results: The V magnitudes of UX Ari we obtained are significantly fainter than those reported in the literature, and they are not consistent with a 25-year period for the mean light level. The increased fractional contribution by the hotter G-type component to the total light in the blue spectral region as the active star becomes faint, seems to be the real cause for the bluer colour of UX Ari at fainter visual magnitudes.

Rosario, M. J.; Raveendran, A. V.; Mekkaden, M. V.

2007-11-01