Feather microstructure predicts size and colour intensity of a melanin-based plumage signal

2011 ◽  
Vol 42 (6) ◽  
pp. 473-479 ◽  
Author(s):  
Ismael Galván
2019 ◽  
Vol 23 (2) ◽  
pp. 193-198
Author(s):  
Monica Mironescu ◽  
Laura Fratila ◽  
Alexandru Hupert ◽  
Ion Dan Mironescu

Abstract This research investigates the physical-chemical, sensorial and mechanical characteristics of starch-based edible films incorporating three types of bee hive products: honey, propolis and bee bread, in concentrations varying from 1% to 3%, reported to starch. The results indicates an increasing of films moisture, water activity, ash content and acidity, in the order: honey<propolis<bee bread, all values increasing with the increasing of hive products percentage into the control film; aw is remaining at very low values, under 0.4. Sensorial analysis indicated honey as the better suited for improving taste and flavour and bee bread for increasing colour intensity of the films; the sensorial characteristics are maintained during 30 days of films storage, in all cases. Compared with the control starch-based film (which is elastic, brittle and hard), the films containing 2% bee hive products are elasto-plastic and more resistant to penetration, the resistance increasing in the order: bee bread<propolis<honey.


2017 ◽  
Vol 68 (3) ◽  
pp. 474-477
Author(s):  
Lacramioara Oprica ◽  
Doina Atofanei ◽  
Vladimir Poroch

The amounts of anthocyanins, flavonoids, total polyphenol and ascorbic acid in seven apple cultivars from Romania were investigated. The amounts of polyphenol and flavonoids in pulp and skin of apple cultivars ranged between 17.18�7.52 mg GAE/g DW and 20.10�11.06 mg CE/g DW as well as 3.64�1.18 mg GAE/g DW and 10.31�5.57 mg CE/g DW, respectively. The highest and smallest values of ascorbic acid both in the skin and the pulp were observed in the cultivars Mutsu and Starkrimson. The anthocyanin content is positively correlated with the colour intensity of the apple epicarp, being about three-fold higher in Prima than Golden Delicious cultivar. The better antioxidant activity provided by the content of polyphenol, ascorbic acid and flavonoids was in apple fruits of Mutsu cultivar and for this reason it should be regarded as a valuable source of antioxidants.


2021 ◽  
Vol 26 ◽  
pp. 53-56
Author(s):  
A. O. Fanimo ◽  
A. B. J. Aina ◽  
E. B. Oguntona

Two experiments were conducted concurrently to assess the effect of different levels of fresh and dry Tridax procumbens on performance of layers. 720 Hbbard layers were grouped into 6 treatments of 60 birds per treatment in each experiment. The treatment in consisted of 0, 2, 4, 6, 8 and 10% inclusion rates of fresh and dry Tridax procumbens in first and second experiments, respectively. Tridax leaves, irrespective of the form and level had no significantly (P > 0.05) effect on egg production, egg weight and feed intake. Inclusion of Tridax either in fresh or dry form increased (P < 0.05) yolk colour, while the yolk colour intensity was more pronounced (P < 0.05) in the dry Tridax than the fresh Tridax experiment.


2017 ◽  
Vol 1 (1) ◽  
pp. 89-94
Author(s):  
Sherwan Kafoor

Asnawa soils contain high amounts of iron oxides. These minerals apply much influence on different soil properties, of which the most observable is colour. The objective of this study was to conclude if colour of soils measured by visual methods can be parameterized to quantify soil Fe oxides. The examined area was divided to three zones (zone A, zone B and zone C) according to their colour intensity. Forty soil samples were examined for their colour and iron oxide contents. Their colour were ranged between 5YR (H) 2.5 (V/C) to 5YR (H) 5/8 (V/C). The average values of free Fe oxide in the soils of the three zones were 52.1%, 36.8% and 15.9% respectively. A new formula was derived to measure colour intensity. A highly significant correlation was found between colour intensity and concentrations of Fe oxides in the examined soils.


2005 ◽  
Vol 11 (5) ◽  
pp. 345-352 ◽  
Author(s):  
A. I. Cascales ◽  
E. Costell ◽  
F. Romojaro

Sensory quality of peach during ripening to assess the best state for consumption was analysed. Physical and chemical parameters commonly used for establishing the commercial quality of this fruit were also determined: Soluble solids, acidity, sugars, organic acids, chlorophyll, carotenoids, resistance to compression and to penetration and colour. Relationships among these parameters and sensory characteristics were also analysed. A panel of eight trained assessors evaluated intensities of 12 sensory attributes (1 for odour, 2 for colour, 4 for flavour and 5 for texture). The sensory attributes selected allowed the description of perceivable differences between peaches of different degrees of maturity, although the variation in intensity of the attributes followed different trends. Colour intensity increased and acidity, firmness and crispness decreased significantly with ripening. Intensity of flavour, sweetness and fruitiness increased significantly from the under-ripe to semi-ripe states, and then decreased on reaching ripeness. It can be concluded that the most suitable time for harvesting and consumption of this peach variety was the state described herein as semi-ripe, and that a high correlation existed between colour intensity and hardness and the instrumental measurements of colour and texture.


The Auk ◽  
2018 ◽  
Vol 135 (3) ◽  
pp. 777-787 ◽  
Author(s):  
Felicia B. Kulp ◽  
Liliana D'Alba ◽  
Matthew D. Shawkey ◽  
Julia A. Clarke

2011 ◽  
Vol 3 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Md. Ibrahim Khalil ◽  
Mohamed Mahaneem ◽  
Syed Mohsin Sahil Jamalullail ◽  
Nadia Alam ◽  
Siti Amrah Sulaiman

2019 ◽  
Vol 128 (3) ◽  
pp. 550-568 ◽  
Author(s):  
Marie Fan ◽  
Liliana D’alba ◽  
Matthew D Shawkey ◽  
Anne Peters ◽  
Kaspar Delhey

AbstractClosely related species often differ in coloration. Understanding the mechanistic bases of such differences can reveal whether evolutionary changes in colour are driven by single key mechanisms or changes in multiple pathways. Non-iridescent structural plumage colours in birds are a good model in which to test these questions. These colours result from light absorption by pigments, light scattering by the medullary spongy layer (a nanostructure found within barbs) and contributions from other structural elements. Fairy-wrens (Malurus spp.) are a small clade of closely related birds that display a large diversity of ornamental structural colours. Using spectrometry, electron microscopy and Fourier analysis, we show that 30 structural colours, varying from ultraviolet to blue and purple, share a similar barb morphology. Despite this similarity, we find that at the microscopic scale, variation across multiple structural elements, including the size and density of the keratin cortex, spongy layer and melanin, explains colour diversity. These independent axes of morphological variation together account for sizeable amounts of structural colour variability (R2 = 0.21–0.65). The coexistence of many independent, evolutionarily labile mechanisms that generate colour variation suggests that the diversity of structural colours in this clade could be mediated by many independent genetic and environmental factors.


Clay Minerals ◽  
1983 ◽  
Vol 18 (4) ◽  
pp. 447-458 ◽  
Author(s):  
R. Fahn ◽  
K. Fenderl

AbstractDuring the reaction of solutions of the leuco dyes crystal violet lactone and N-benzoyl leuco methylene blue with acid-treated montmarillonite (as occurs with carbonless copying papers), most of the offered dye is intercalated within the interlayers of the montmorillonite structure remaining after acid attack. This phenomenon was demonstrated by XRD and also by high-resolution transmission electron microscopy. During acid treatment, octahedral cations are dissolved from exposed edges of the montmorillonite lamellae and amorphous silica builds up in these areas. As a result, the BET(N2) specific surface area increases from ∼60 m2/g to ∼300 m2/g and, consequently, the theoretical reactivity towards leuco dyes. Nevertheless, only small quantities of the dye molecules are adsorbed onto the amorphous silica. The excellent colour intensity and, in particular, the resistance to fading in the light of the montmorillonite dye complexes may be explained by the protected position of the dye molecules within the interlayers of the montmorillonite.


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