scholarly journals Visual signal evolution along complementary color axes in four bird lineages

2019 ◽  
Author(s):  
Anand Krishnan ◽  
Avehi Singh ◽  
Krishnapriya Tamma
Keyword(s):  
Color Space ◽  
Dietary Factors ◽  
The Body ◽  
Color Variation ◽  
Visual Signals ◽  
Visual Signal ◽  
Relative Role ◽  
Chromatic Contrast ◽  
Present Evidence ◽  
Complementary Color

AbstractAnimal color patterns function in varied behavioral contexts including recognition, camouflage and even thermoregulation. The diversity of visual signals may be constrained by various factors, for example, dietary factors, and the composition of ambient environmental light (sensory drive). How have high-contrast and diverse signals evolved within these constraints? In four bird lineages, we present evidence that plumage colors cluster along a line in tetrachromatic color space. Additionally, we present evidence that this line represents complementary colors, which are defined as opposite sides of a line passing through the achromatic point (putatively for higher chromatic contrast). Finally, we present evidence that interspecific color variation over at least some regions of the body is not constrained by phylogenetic relatedness. Thus, we hypothesize that species-specific plumage patterns within these bird lineages evolve by swapping the distributions of a complementary color pair (or dark and light patches in one group, putatively representing an achromatic complementary axis). The relative role of chromatic and achromatic contrasts in discrimination may depend on the environment that each species inhabits.

scholarly journals Visual signal evolution along complementary color axes in four bird lineages

Biology Open ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. bio052316
Author(s):  
Anand Krishnan ◽  
Avehi Singh ◽  
Krishnapriya Tamma
Keyword(s):  
Color Space ◽  
The Body ◽  
Color Variation ◽  
Visual Signals ◽  
Visual Signal ◽  
Chromatic Contrast ◽  
Present Evidence ◽  
Complementary Color ◽  
Line Passing ◽  
Species Specific

ABSTRACTAvian color patterns function in varied behavioral contexts, most being produced by only a handful of mechanisms including feather nanostructures and pigments. Within a clade, colors may not occupy the entire available space, and incorporating complementary colors may increase the contrast and efficacy of visual signals. Here, we describe plumage patterns in four ecologically and phylogenetically diverse bird families to test whether they possess complementary colors. We present evidence that plumage colors in each clade cluster along a line in tetrachromatic color space. Additionally, we present evidence that in three of these clades, this line contains colors on opposite sides of a line passing through the achromatic point (putatively complementary colors, presenting higher chromatic contrast). Finally, interspecific color variation over at least some regions of the body is not constrained by phylogenetic relatedness. By describing plumage patterns in four diverse lineages, we add to the growing body of literature suggesting that the diversity of bird visual signals is constrained. Further, we tentatively hypothesize that in at least some clades possessing bright colors, species-specific plumage patterns may evolve by swapping the distributions of a complementary color pair. Further research on other bird clades may help confirm whether these patterns are general across bird families.

scholarly journals How to colour a flower: on the optical principles of flower coloration

2016 ◽  
Vol 283 (1830) ◽  
pp. 20160429 ◽  
Author(s):  
Casper J. van der Kooi ◽  
J. Theo M. Elzenga ◽  
Marten Staal ◽  
Doekele G. Stavenga
Keyword(s):  
Optical Model ◽  
Systematic Approach ◽  
Species Differences ◽  
Flower Colour ◽  
Insect Vision ◽  
Visual Signals ◽  
Visual Signal ◽  
Selective Absorption ◽  
Chromatic Contrast ◽  
Selective Pressures

The coloration of flowers is due to the wavelength-selective absorption by pigments of light backscattered by structures inside the petals. We investigated the optical properties of flowers using (micro)spectrophotometry and anatomical methods. To assess the contribution of different structures to the overall visual signal of flowers, we used an optical model, where a petal is considered as a stack of differently pigmented and structured layers and we interpreted the visual signals of the model petals with insect vision models. We show that the reflectance depends, in addition to the pigmentation, on the petal's thickness and the inhomogeneity of its interior. We find large between-species differences in floral pigments, pigment concentration and localization, as well as floral interior structure. The fractions of reflected and transmitted light are remarkably similar between the studied species, suggesting common selective pressures of pollinator visual systems. Our optical model highlights that pigment localization crucially determines the efficiency of pigmentary filtering and thereby the chromatic contrast and saturation of the visual signal. The strongest visual signal occurs with deposition of pigments only on the side of viewing. Our systematic approach and optical modelling open new perspectives on the virtues of flower colour.

Androgen receptor modulates multimodal displays in the Bornean rock frog (Staurois parvus)

2021 ◽  
Author(s):  
Sarah M Smith ◽  
Amelia R Eigerman ◽  
Kerry M LeCure ◽  
Eseza Kironde ◽  
Auxenia Grace Privett-Mendoza ◽  
...  
Keyword(s):  
The Body ◽  
Visual Signals ◽  
Visual Signal ◽  
Dependent Manner ◽  
Adult Males ◽  
Physiological Basis ◽  
Temporal Properties ◽  
Signal Production ◽  
Vocal Signaling

Abstract Multimodal communication is common in the animal kingdom. It occurs when animals display by stimulating two or more receiver sensory systems, and often arises when selection favors multiple ways to send messages to conspecifics. Mechanisms of multimodal display behavior are poorly understood, particularly with respect to how animals coordinate the production of different signals. One important question is whether all components in a multimodal display share an underlying physiological basis, or whether different components are regulated independently. We investigated the influence of androgen receptors (AR) on the production of both visual and vocal signal components in the multimodal display repertoire of the Bornean rock frog (Staurois parvus). To assess the role of AR in signal production, we treated reproductively active adult males with the antiandrogen flutamide and measured the performance of each signal in the multimodal display. Our results show that blocking AR inhibited the production of multiple visual signals, including a conspicuous visual signal known as the “foot flag,” which is produced by rotating the hind limb above the body. However, flutamide treatment caused no measurable change in vocal signaling behavior, or in the frequency or fine temporal properties of males’ calls. Our study therefore suggests that activation of AR is not a physiological prerequisite to the coordination of multiple signals, in that it either does not regulate all signaling behaviors in a male’s display repertoire or it does so only in a context-dependent manner.

scholarly journals Possible mechanisms of anosognosia: a defect in self–awareness

1998 ◽  
Vol 353 (1377) ◽  
pp. 1903-1909 ◽  
Author(s):  
◽  
K. M. Heilman ◽  
A. M. Barrett ◽  
J. C. Adair
Keyword(s):  
Population Study ◽  
Sensory Feedback ◽  
Large Population ◽  
The Body ◽  
Spatial Neglect ◽  
Self Awareness ◽  
Knowledge Of Results ◽  
Present Evidence ◽  
Sensory Deficits ◽  
Parallel Processes

Anosognosia of hemiplegia is of interest for both pragmatic and theoretical reasons. We discuss several neuropsychological theories that have been proposed to explain this deficit. Although for psychological reasons people might deny deficits, the denial hypothesis cannot account for the hemispheric asymmetries associated with this disorder and cannot explain why some patients might deny one deficit and recognize another equally disabling deficit. There is some evidence that faulty feedback from sensory deficits, spatial neglect and asomatognosia might be responsible for anosognosia in some patients. However, these feedback hypotheses cannot account for anosognosia in all patients. Although the hemispheric disconnection hypothesis is appealing, disconnection is probably only a rare cause of this disorder. The feedforward intentional theory of anosognosia suggests that the discovery of weakness is dependent on attempted action and some patients might have anosognosia because they do not attempt to move. We present evidence that supports this theory. The presence of one mechanism of anosognosia, however, does not preclude the possibility that other mechanisms might also be working to produce this disorder. Although a large population study needs to be performed, we suspect that anosognosia might be caused by several of the mechanisms that we have discussed. On the basis of the studies of impaired corporeal self–awareness that we have reviewed, we can infer that normal self–awareness is dependent on several parallel processes. One must have sensory feedback and the ability to attend to both one's body and the space where parts of the body may be positioned or acting. One must develop a representation of the body, and this representation must be continuously modified by expectations (feedforward) and knowledge of results (feedback).

Pathology in Antechinus stuartii (Marsupialia) due to Demodex sp.

Parasitology ◽  
1965 ◽  
Vol 55 (2) ◽  
pp. 383-389 ◽  
Author(s):  
William Nutting ◽  
Patricia Woolley
Keyword(s):  
Hair Follicle ◽  
Technical Assistance ◽  
Dietary Factors ◽  
The Body ◽  
Follicular Epithelium ◽  
University Of Pennsylvania ◽  
Nodule Formation ◽  
Industrial Research Organization ◽  
Antechinus Stuartii ◽  
Demodex Sp

Pathological manifestations occasioned by mites of the genus Demodex are reported from Antechinus stuartii, a marsupial mouse. Derangements from single mite invasion of a hair follicle to massive nodule formation are detailed. In heavy infestations mites are found well distributed in the skin of the body with nodules limited, however, to the head, hind legs, around the base of the tail, the cloacal regions and, in females, just anterior to the pouch area.Mites invade the hair follicle, where increase in their numbers leads to hypertrophy of the follicular epithelium which forms marked lobules surrounded by heavily vascularized connective tissue. It is thought that destruction of the lobule cells and penetration of the blood vessels due to increased mite numbers and activity leads to leucocytic infiltration with destruction of the mites and nodule deflation. In two instances of nodule deterioration a thickened skin plaque with markedly reduced mite populations remained in place of the nodule.Gross symptoms of demodicidosis are occasionally marked in animals maintained in the laboratory but have not been found in specimens from the field. This suggests that environmental or dietary factors may be important in the onset of gross symptoms of demodicidosis.This investigation was supported in part by a National Science Foundation (U.S.A.) grant (G-23321) and by a Commonwealth Scientific and an Industrial Research Organization (Australia) grant for marsupial research to the Zoology Department, A.N.U.Dr Herman Beerman, Professor and Chairman, Department of Dermatology, Graduate School of Medicine, University of Pennsylvania, very kindly read and criticized our interpretation of the pathology. We are grateful for his help.We would like to thank Margaret Dahlquist, Research Assistant, for her excellent technical assistance in the preparation of material for this report.

scholarly journals Six-Month Color Stability Assessment of Two Calcium Silicate-Based Cements Used in Regenerative Endodontic Procedures

2019 ◽  
Vol 10 (1) ◽  
pp. 14 ◽  
Author(s):  
Paulo Palma ◽  
Joana Marques ◽  
Rui Falacho ◽  
Eder Correia ◽  
Alexandra Vinagre ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
Saline Solution ◽  
Color Space ◽  
Mineral Trioxide Aggregate ◽  
Color Stability ◽  
Color Variation ◽  
Color Measurement ◽  
Suitable Alternative ◽  
Significance Level ◽  
Over Time

Aim: The purpose of the present study is to assess the color stability of two calcium silicate-based cements (CSCs) used in regenerative endodontic procedures (REPs). Methods: A total of 40 acrylic single-rooted transparent teeth, with immature apex, were used. Root canals were filled up to 3 mm below the level of the cementoenamel junction, with either saline solution (Mineral Trioxide Aggregate (MTA)/saline and Biodentine/saline) or blood (MTA/blood and Biodentine/blood). Subsequently, ProRoot MTA® or BiodentineTM was placed in the root canal to create a cervical barrier. Color measurement was carried out at four different evaluation periods (3 h, 72 h, 7 days, and 6 months). Shade analysis within the L* a* b* color space was performed and color variation (∆E) calculated. The significance level for statistical analysis was set at p < 0.05. Results: The four groups showed a significant decrease in L* values over time. The ΔE value increased over time for all groups but was not statistically significant for the Biodentine/blood group. Two-way ANOVA showed no interaction between the CSC and treatment (contact with saline solution or blood). CSC used was the factor responsible for ΔE over time, inducing statistically significant color variations from T3H to T7D (p = 0.04) and T3H to T6M (p < 0.01). After 6 months, MTA/saline had 5.08 (p = 0.001) higher ΔE than Biodentine/Saline and the MTA/blood had 3.65 (p = 0.009) higher than Biodentine/blood. Conclusions: After 6 months, regardless of blood exposure, Biodentine exhibits superior color stability compared to MTA. Biodentine might be a suitable alternative to MTA as a cervical barrier material in REPs.

scholarly journals Dietary factors affecting the maximum feed intake and the body composition of pre-ruminant kid goats of the Granadina breed

1995 ◽  
Vol 74 (3) ◽  
pp. 335-345 ◽  
Author(s):  
M. R. Sanz Sampelayo ◽  
L. Allegretti ◽  
I. Ruiz Mariscal ◽  
F. Gil Extremera ◽  
J. Boza
Keyword(s):  
Body Composition ◽  
Feed Intake ◽  
Protein Concentration ◽  
Diet Composition ◽  
Dietary Factors ◽  
The Body ◽  
Metabolizable Energy ◽  
Factors Affecting ◽  
Digestible Protein ◽  
Milk Replacers

An experiment was carried out with kid goats of the Granadina breed to identify the dietary factors affecting voluntary feed intake of the kid goat and those that additively could determine its body composition. The animals used were from birth to 61 d of age, fed ad lib. on different milk replacers containing 200, 240 and 280 g crude protein/kg DM and 200, 240 and 280 g fat/kg DM, thus giving nine dietary treatments. The utilization of the milk replacers and the animals' body composition were determined by balance and slaughter trials. There were significant positive effects of protein concentration of the milk replacers on component digestibilities, energy metabolizability, feed intake, empty-body weights, empty-body composition and protein and fat retention. The concentration of fat in the milk replacers also had a significant positive effect on the digestible and metabolizable energy concentration of the diets and on fat retention. The relationships existing between feed intake and diet composition (concentration of digestible protein, metabolizable energy and digestible protein:metabolizable energy ratio) as well as between empty-body composition or protein and fat retention and diet composition, were examined. From these it was deduced that feed intake was significantly influenced by the digestible protein concentration of the diets. The higher the digestible protein concentration the higher the feed intake up to a maximum digestible protein concentration value. As the digestible protein concentration of the diets was the dietary factor which significantly influenced feed intake, this also significantly influenced the body composition and the protein and fat retention. The protein concentration of the feed at which metabolizable energy intake in these animals would be greatest was estimated to be 347 g/kg DM.

scholarly journals Skin color variation: A study on Eastern and North East India

2019 ◽  
Vol 10 (3) ◽  
pp. 13-16
Author(s):  
Sumit Maitra ◽  
Diptendu Chatterjee ◽  
Arup Ratan Bandyopadhyay
Keyword(s):  
Ethnic Groups ◽  
Skin Color ◽  
Skin Pigmentation ◽  
Color Space ◽  
Color Variation ◽  
Phenotypic Traits ◽  
North East India ◽  
North East ◽  
Wide Range ◽  
Significant Difference

Background: Skin pigmentation is one of the most variable phenotypic traits and most noticeable of human polymorphisms. Skin pigmentation in humans is largely determined by the quantity and distribution of the pigment melanin. The literature review on skin color variation revealed a few works on skin pigmentation variation has been conducted in India from Southern, Western and Northern part. Aims and Objectives: To best of the knowledge, the present discourse is the first attempt to understand skin color variation from Eastern and North Eastern part of India among three populations. Materials and Methods: The present study consisted of 312 participants from Chakma and Tripuri groups of Tripura, North East India, and participants from Bengalee Hindu caste population from West Bengal. Skin color was measured by Konica Minolta CR-10 spectrophotometer which measures and quantifies the colors with a 3D color space (CIELAB) color space created by 3 axes. All the skin color measurements from each participant were taken from unexposed (underarm) left and right to get a mean and exposed (forehead) to sunlight. Results: The distribution of skin color variation among the three populations demonstrated significant (p<0.05) difference in lightness for unexposed and exposed indicating lightness in unexposed area. Furthermore, the present study revealed significant difference (p<0.05) in skin color among the ethnic groups across the body location and all three attributes (lightness, redness and yellowness). Conclusion: Generally, skin color variation may be elucidated by two main factors: individual differences in lightness and yellowness and by and large due to ethnicity, where diversity in redness is due to primarily due to different body locations. Variation in lightness have more characteristic probability. The present study first time reports the wide range of quantitative skin color variation among the three ethnic groups from Eastern and North East India and highest yellowness (b*) among the population from North East India.

The colouration and its behavioural significance in the corkwing wrasse, Crenilabrus melops

1974 ◽  
Vol 54 (4) ◽  
pp. 925-938 ◽  
Author(s):  
G. W. Potts
Keyword(s):  
Functional Significance ◽  
Mature Male ◽  
The Body ◽  
Visual Signals ◽  
Male Courtship ◽  
Male And Female ◽  
Vertical Bars ◽  
Mature Fish ◽  
Colour Patterns ◽  
Behavioural Significance

The colour patterns of the corkwing wrasse Crenilabrus melops and the functional significance of these patterns has been described. The resting colours of the fish are described for juveniles, mature males and mature females. These colour patterns assist in making the fish less conspicuous in their natural environment. Agonist behaviour is characterized by the development of a series of vertical bars on the body together with ritualized lateral and frontal displays in aggressive, and a head-up submissive posture in fright situations. Most aggressive behaviour is associated with the territorial activity of the mature male. Courtship and spawning activities involve a complex series of visual signals that synchronize the roles played by the male and female. The differences in colouration between juvenile and mature fish and the changes any individual can display have wrongly lead earlier authors to split C. melops into different species or varieties.

The influence of the shift work system on dietary factors contributing to the development of cardiovascular diseases

2019 ◽  
Vol 88 (2) ◽  
pp. 96-101
Author(s):  
Małgorzata Anna Dobrzyńska ◽  
Ilona Górna ◽  
Grzegorz Kosewski ◽  
Magdalena Kowalówka ◽  
Izabela Bolesławska ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Shift Work ◽  
Eating Behaviors ◽  
Night Shift ◽  
Daily Intake ◽  
Dietary Factors ◽  
The Body ◽  
Dietary Recall ◽  
Work System ◽  
Daily Food

Aim. The aim of this study was to assess eating behavior in the groups of women who are working on different, unchanged shifts as well as identifying differences in the consumption of nutrients that may increase the risk of cardiovascular disease.Material and Methods. The study was carried out among 300 randomly selected women working in a permanent shift (morning, afternoon, night). In the study, the assessment of the daily intake was carried out using 24-h dietary recall. Anthropometric measurements were carried out to assess the nutritional status. The interview regarding the food consumption was complemented by dietary questionnaire about selected lifestyle parameters contributing to the development of cardiovascular disease and the type of their work.Results. The body mass index (BMI) in all groups was within the adequate values. The analysis of waist to hip ratio (WHR) showed that in the morning and night shift, was exceeded the adequate values recommended in the prevention of cardiovascular disease (WHR = 0.83 ± 0.1 in both groups). The analysis of the daily food rations of women revealed disparities regarding nutritional recommendations. Statistically significant differences in protein and saccharose intake were observed (p > 0.05). The average vitamin D content in the daily food rations of women was insufficient (average 1.4 µg per day); however, it was not statistically significant.Conclusions. The shift work system was influence on eating behaviors in study women. In particular in women which were worked on the night shift, which may contribute to the development of cardiovascular disease in the future.

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