Evaluation of Breathing Pattern: Comparison of a Manual Assessment of Respiratory Motion (MARM) and Respiratory Induction Plethysmography

Altered breathing pattern is an aspect of dysfunctional breathing but few standardised techniques exist to evaluate it. This study investigates a technique for evaluating and quantifying breathing pattern, called the Manual Assessment of Respiratory Motion (MARM) and compares it to measures performed with Respiratory Induction Plethysmography (RIP). About 12 subjects altered their breathing and posture while 2 examiners assessed their breathing using the MARM. Simultaneous measurements with RIP were taken. Inter-examiner agreement and agreement between MARM and RIP were assessed. The ability of the measurement methods to differentiate between diverse breathing and postural patterns was compared. High levels of agreement between examiners were found with the MARM for measures of the upper rib cage relative to lower rib cage/abdomen motion during breathing but not for measures of volume. The measures of upper rib cage dominance during breathing correlated with similar measures obtained from RIP. Both RIP and MARM measures methods were able to differentiate between abdominal and thoracic breathing patterns, but only MARM was able to differentiate between breathing changes occurring as result of slumped versus erect sitting posture. This study suggests that the MARM is a reliable clinical tool for assessing breathing pattern.     

Molecular cytogenetics of Androctonus scorpions: an oasis of calm in the turbulent karyotype evolution of the diverse family Buthidae

After years of qualitative and subjective study, quantitative colour science is now enabling rapid measurement, analysis and comparison of colour traits. However, it has not been determined how many replicates one needs to accurately quantify a species' colours for studies aimed at broad cross‐species trait comparison. We address this major methodological knowledge gap. We first quantified and assessed the variance in colour within and between species. Reflectance spectra of flowers from ten plant species and plumage of 20 bird species were measured using a spectrometer, and reflectance (i.e. brightness) and tetrahedral colour‐space coordinates were calculated. analysis of variance (ANOVA) analyses indicate that there is far more variation in the colours of birds and flowers between species (> 77%) than within species. A Mean Absolute Deviation from the Mean test was applied to indicate the sampling replication required for each species. Tetrahedral coordinates were sampled precisely with only one individual per species. Greater replication was needed to sample reflectance with the desired precision, particularly for darker coloured species. Our findings will allow researchers to allocate their sampling effort in a way that maximises the precision of their colour data collection. The fact that only a few replicates per species are necessary will greatly facilitate broad cross‐species comparisons of colour in the future. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 114 , 69–81.     

Study on the Effects of Tablet Colour in the Treatment of Anxiety States

Forty-eight patients with anxiety states were treated with oxazepam (Serenid-D), which was administered in tablets of three different colours—red, yellow, and green. Every patient received one week''s treatment with each colour, according to a random programme. A latin square design was used to ensure complete balance between the colours and between the weeks. The patients'' symptoms were categorized and then assessed by both weekly physicians'' ratings and daily self-rating, which showed close agreement. Colour preference was shown on both these scales in that symptoms of anxiety were most improved with green, whereas depressive symptoms appeared to respond best to yellow. Such colour preferences, however, did not reach levels of statistical significance, except for phobias as rated on the physicians'' assessment.The results indicate that colour may play a part in the response to a drug.     

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

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

An empirical link between the spectral colour of climate and the spectral colour of field populations in the context of climate change

1. The spectral colour of population dynamics and its causes have attracted much interest. The spectral colour of a time series can be determined from its power spectrum, which shows what proportion of the total variance in the time series occurs at each frequency. A time series with a red spectrum (a negative spectral exponent) is dominated by low-frequency oscillations, and a time series with a blue spectrum (a positive spectral exponent) is dominated by high-frequency oscillations. 2. Both climate variables and population time series are characterised by red spectra, suggesting that a population's environment might be partly responsible for its spectral colour. Laboratory experiments and models have been used to investigate this potential link. However, no study using field data has directly tested whether populations in redder environments are redder. 3. This study uses the Global Population Dynamics Database together with climate data to test for this effect. We found that the spectral exponent of mean summer temperatures correlates positively and significantly with population spectral exponent. 4. We also found that over the last century, temperature climate variables on most continents have become bluer. 5. Although population time series are not long or abundant enough to judge directly whether their spectral colours are changing, our two results taken together suggest that population spectral colour may be affected by the changing spectral colour of climate variables. Population spectral colour has been linked to extinction; we discuss the potential implications of our results for extinction probability.     

The colour of flowers in spectrally variable illumination and insect pollinator vision

The spectral reflectance of differently coloured Australian native plant flowers and foliage was measured and plotted in a colour triangle to represent the colour space of the honeybee. Spectral variations in illumination are shown to significantly change plant colours for bee vision without colour constancy. A model of chromatic adaptation based upon the von Kries coefficient law shows a reduction in plant colour shift, with the degree of correction depending upon position in colour space. A set of artificial reflectances is used to map relative colour shift caused by spectrally variable illumination for the entire colour space of the honeybee. The rarity of some flower colours in nature shows a correlation to a larger colour shift for these colours when illuminated by spectrally variable radiation. The model of chromatic adaptation is applied to illuminations used in a behavioural study on honeybee colour constancy by Neumeyer 1981. Surface colours used by Neumeyer are plotted in colour space for the various illuminations. The results show that an illumination-dependent colour shift correlates to a decrease in the frequency of bees correctly choosing a colour to which it was trained. Accepted: 23 February 1998     

Effect of colour of drugs: systematic review of perceived effect of drugs and of their effectiveness.

OBJECTIVE: To assess the impact of the colour of a drug''s formulation on its perceived effect and its effectiveness and to examine whether antidepressant drugs available in the Netherlands are different in colour from hypnotic, sedative, and anxiolytic drugs. DESIGN: Systematic review of 12 published studies. Six studies examined the perceived action of different coloured drugs and six the influence of the colour of a drug on its effectiveness. The colours of samples of 49 drugs affecting the central nervous system were assessed using a colour atlas. MAIN OUTCOME MEASURES: Perceived stimulant action versus perceived depressant action of colour of drugs; the trials that assessed the effect of drugs in different colours were done in patients with different diseases and had different outcome measures. RESULTS: The studies on perceived action of coloured drugs showed that red, yellow, and orange are associated with a stimulant effect, while blue and green are related to a tranquillising effect. The trials that assessed the impact of the colour of drugs on their effectiveness showed inconsistent differences between colours. The quality of the methods of these trials was variable. Hypnotic, sedative, and anxiolytic drugs were more likely than antidepressants to be green, blue, or purple. CONCLUSIONS: Colours affect the perceived action of a drug and seem to influence the effectiveness of a drug. Moreover, a relation exists between the colouring of drugs that affect the central nervous system and the indications for which they are used. Research contributing to a better understanding of the effect of the colour of drugs is warranted.     

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

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.     

Geographic patterns in fruit colour diversity: do leaves constrain the colour of fleshy fruits?

We tested for geographic patterns in fruit colour diversity. Fruit colours are thought to promote detection by seed dispersers. Because seed dispersers differ in their spectral sensitivities, we predicted that fruit colour diversity would be higher in regions with higher seed disperser diversity (i.e. the tropics). We collected reflectance data on 232 fruiting plant species and their natural backgrounds in seven localities in Europe, North and South America, and analysed fruit colour diversity according to the visual system of birds—the primary consumer types of these fruits. We found no evidence that fruit colours are either more conspicuous or more diverse in tropical areas characterised by higher seed disperser diversity. Instead, fruit colour diversity was lowest in central Brazil, suggesting that fruit colours may be more diverse in temperate regions. Although we found little evidence for geographic variation in fruit hues, the spectral properties of fruits were positively associated with the spectral properties of backgrounds. This result implies that fruit colours may be influenced by selection on the reflectance properties of leaves, thus constraining the evolution of fruit colour. Overall, the results suggest that fruit colours in the tropics are neither more diverse nor more conspicuous than temperate fruits, and that fruit colours may be influenced by correlated selection on leaf reflectance properties. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Visual discrimination by the honeybee (Apis mellifera): the position of the common centre as the cue

Abstract. Bees can be trained to discriminate between a target with a 20° spot above a 10° spot of the same colour, and another target with the spots exchanged in position. Tests show that they do not remember the separate positions of spots of the same colour (including black) on the same target. The bees discriminate the difference in positions, in the vertical direction, of the common centres of the spots taken together, with or without green contrast.
Similar results are obtained in discriminations of a fixed T shape, each composed of two broad black bars subtending 8 by 24°, vs the same shape inverted. The trained bees fail to discriminate between the T shapes when the centroids are at the same level in the vertical direction. Moving the shapes in the horizontal direction in tests has less effect. Quite different results are obtained when the two bars of the T shape differ in colour. The bees discriminate the positions of the two colours separately, but they still fail to discriminate the shape of the T. The results can be explained by filters that detect the intensities within their fields, irrespective of shape, and weigh them according to their vertical angles from the horizontal midline. The normal function of these filters could be to detect the levels of objects relative to the horizon when the bee is in flight.     

Insect colour preference compared to flower colours in the Australian Alps

An apparent predominance of plant taxa with pale flowers in the alpine floras of Australia and New Zealand may be due to the prevalence of insects, such as flies, that prefer pale colours and the absence of other types of potential pollinators that are attracted to bright colours such as social bees and birds. In this study, the diversity of flower colours, and the preference of insects for different colours were examined for the largest contiguous alpine area in Australia, around Mt Kosciuszko. Out of an alpine flora of 204 taxa, 127 species were found to have large showy flowers. The most common flower colour among these taxa was white (53.5%), then yellow (21.3%), followed by pink (6.3%), and cream (6.3%). Only a handful of taxa had red, blue, brown, green, orange or purple flowers. When the colour preference of insects was tested using five different coloured traps (white, yellow, orange, red and purple), the most successful traps were white then yellow, with these two colours accounting for 66% of all individual insects collected. Diptera were the most common insects caught (576 insects greater than 4 mm in length, 31 morphotaxa) showing an apparent preference for white and yellow coloured traps over others. Therefore, the results add some support to the proposition that the 'white' flora of the Australian Alps may be associated with the colour preference of flies, which have previously been found to be the most common type of pollinators in the Kosciuszko alpine zone.     

Selection by passerine birds is anti-apostatic at high prey density

Most of the results from past experiments with wild birds and green and brown pastry 'baits' have suggested that disproportionately more of the rare forms are eaten when bait density is high (i.e. selection is anti-apostatic). In two separate series of experiments we presented birds with dishes containing 270 baits of one colour and 30 of another. In series I, five different pairs of colours were presented simultaneously to wild birds at two sites. One colour of each pair was common at one site and the same colour was rare at the other site. After 35 days the ratios of the colours were reversed and the dishes were presented for another 35 days. There was a statistically significant tendency for the colours to be at a higher risk when rare. In series II, three caged blackbirds were offered green and brown baits in two dishes simultaneously; in one dish green was rare and in the other brown was rare. Selection over 6 days was anti-apostatic for all three birds combined but the data proved heterogeneous both between and within individuals. At any one time, each bird tended to concentrate on one colour, irrespective of whether that colour was rare or common. We believe that this behaviour leads to anti-apostatic selection, as has been observed in these and other experiments with pastry prey.     

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

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.     

Colour plasticity and background matching in a threespine stickleback species pair

Examining differences in colour plasticity between closely‐related species in relation to the heterogeneity of background colours found in their respective habitats may offer important insight into how cryptic colour change evolves in natural populations. In the present study, we examined whether nonbreeding dorsal body coloration has diverged between sympatric species of stickleback along with changes in habitat‐specific background colours. The small, limnetic species primarily occupies the pelagic zone and the large, benthic species inhabits the littoral zone. We placed benthic and limnetic sticklebacks against extremes of habitat background colours and measured their degree of background matching and colour plasticity. Benthics matched the littoral background colour more closely than did the limnetics, although there was no difference between species in their resemblance to the pelagic background colour. Benthics were able to resemble both background colours by exhibiting greater directional colour plasticity in their dorsal body coloration than limnetics, which may be an adaptive response to the greater spectral heterogeneity of the littoral zone. The present study highlights how habitat‐specific spectral characteristics may shape cryptic coloration differences between stickleback species. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 902–914.     

Supergenes in polymorphic land snails. I. Partula taeniata.

The general colour of the shell in Partula taeniata is controlled by at least two loci. One of these (C) has a series of six alleles which determine the yellow (Y) and neutral brown (N) series of colours. Alleles for darker colours are dominant to those for lighter colours, but dominance is not always complete. The pink (P) colours are determined by a second locus (P) which modified the expression of the lighter alleles of the C locus. Orangeshell colour segregates with yellow but its allelic relationship is unknown. Colour of the lip is controlled by a locus (L) with pink lip dominant to white lip. The colour of the spire is determined by a locus (S) with dark (N4) spire dominant to light spire. An intermediate spire colour shows the same pattern of inheritance and may represent the effect of another allele. Banding of the shell is dominant to absence of bands, with two loci (B1 and B2) determining the type of banding. An allele at B1 produces the frenata pattern; an allele at B2 produces zonata; together they produce lyra. All the loci for which linkage data are available are linked so strongly that the whole array may be considered a supergene. Self-fertilisation takes place primarily during early reproductive life. About 20 per cent of the young of the first mating of an individual are produced by selfing, but over the whole reproductive span the frequency is only about 2-5 per cent. There is inconclusive evidence for heterozygote advantage of banded individuals.     

Bumblebees (<Emphasis Type="Italic">Bombus terrestris</Emphasis>) sacrifice foraging speed to solve difficult colour discrimination tasks

The performance of individual bumblebees at colour discrimination tasks was tested in a controlled laboratory environment. Bees were trained to discriminate between rewarded target colours and differently coloured distractors, and then tested in non-rewarded foraging bouts. For the discrimination of large colour distances bees made relatively fast decisions and selected target colours with a high degree of accuracy, but for the discrimination of smaller colour distances the accuracy decreased and the bees response times to find correct flowers significantly increased. For small colour distances there was also significant linear correlations between accuracy and response time for the individual bees. The results show both between task and within task speed-accuracy tradeoffs in bees, which suggests the possibility of a sophisticated and dynamic decision-making process.     

WWW design code - a new tool for colour estimation in animal studies

BACKGROUND: The colour of animals' skin, fur, feathers or cuticula has been estimated in a large number of studies. The methods used to do so are diverse, with some being costly and not available to all researchers. In a study to measure plumage colour in a bird species, a new method of creating a colour chart was developed. While colour-charts have their own limitations, these can be minimised when they have the following properties: 1) being readily available to the majority of biologists, 2) containing a large array of colours to allow accurate recording and differentiation of subtle colour differences, 3) low cost, 4) adhering to a world-wide standard, and 5) being available in both hard-copy and digital formats to allow for various analytical methods. The method described below satisfies all of these requirements. RESULTS: Colour charts estimated to fit the range of the species' plumage colours were created on the computer screen using web software that allowed for HTML-coding (in this case Dreamweavertrade mark). The charts were adjusted using feathers from dead specimens until a satisfying range of darker and lighter colours were found. The resulting chart was printed out and was successfully used in the field to determine the plumage colour of hand-held birds. CONCLUSION: Access to a computer and printer, and the software to enable the creation of a chart, is within the reach of the vast majority of biologists. The numbers of colours that can be generated should suit most studies, with the advantage of the method being that the chart can be individually tailored to the species under study. HTML colour coding is a worldwide standard, thus the colours used in studies can be described in the methods section of journal articles using the six-digit alphanumeric code. We believe this method is very useful as a low-tech method for future estimation of individual colour.     

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

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.     

Ultraviolet nuptial colour determines fight success in male European green lizards (Lacerta viridis)

Animal communication through colour signals is a central theme in sexual selection. Structural colours can be just as costly and honest signals as pigment-based colours. Ultraviolet (UV) is a structural colour that can be important both in intrasexual competition and mate choice. However, it is still unknown if a UV signal alone can determine the outcome of male-male fights. European green lizard (Lacerta viridis) males develop a nuptial throat coloration with a strong UV component. Among males differing only in their manipulated UV colour, females prefer males with higher UV. Here, we experimentally decreased the UV coloration of randomly chosen males from otherwise similar male pairs to test the hypothesis that a difference in UV colour alone can affect fight success during male-male competition. Our results fully supported the hypotheses: in almost 90 per cent of the contests the male with reduced UV lost the fight. Our results show that UV can be an important signal, affecting both female mate choice and determining male fight success.     

Temporal acuity of honeybee vision: behavioural studies using flickering stimuli

ABSTRACT. Temporal resolution of freely-flying bees was measured by training bees, Apis mellifera (Linn.), to discriminate between a steady light and a flickering light. Two kinds of experiments were conducted: those using a homochromatic flicker, in which the intensity of the flickering light varied periodically with time; and ones using a heterochromatic flicker, in which the colour of the flickering light varied periodically. In either case, the time-averaged properties (intensity and colour) of the flickering light matched those of the steady light, and the bees' ability to discriminate between the two stimuli was measured for various flicker frequencies. The results indicate that bees perform poorly in the homochromatic flicker experiments, regardless of the colour of the light (u.v., blue or green), but well in those with heterochromatic flicker. Heterochromatic flicker experiments using various pairwise combinations of the colours U.V., blue and green (corresponding to the three known spectral receptor-types in the bee's retina) reveal that temporal resolution is much better when blue is one of the component colours, than when it is not. The simplest interpretation of the results is in terms of colour channels possessing different response speeds. Heterochromatic flicker promises to be a useful tool in investigating the temporal properties of colour vision in bees.