Background: Co(II) constitutes a part of vitamin B12, hence, it is necessary for human health. However, at concentrations higher than the permissible limits, humans and animals suffer adverse chronic effects. It is necessary to reduce the concentration to a permissible level. In the present study, pre-purification and thermal modification of chicken’s feather increased their porosity and ...

Noniridescent coloration by the spongy keratin in parrot feather barbs has fascinated scientists. Nonetheless, its ultimate origin remains as yet unanswered, and a quantitative structural and optical description is still lacking. Here we report on structural and optical characterizations and numerical simulations of the blue feather barbs of the scarlet macaw. We found that the sponge in the fe...

this study seeks to describe and discuss a hemistich, namely ‘‘yours the earth, mine the vulture’s feather’’, of the story of rostam and sohrab in ferdowsi's shahnameh. many commentators and interpreters of the shahnameh have different opinions on the concept and meaning of this hemistich. this has led the researchers to seek the reason of such differences, clues for the provided meanings,...

In Drosophila, it has been shown that protein kinase A and hedgehog have antagonistic actions during the formation of imaginal disks. In vertebrate skin, sonic hedgehog is expressed specifically in the feather bud epithelia. using an in vitro explant culture model we showed that dibutyryl cAMP, a protein kinase A (PKA) activator, suppresses the expression of Sonic hedgehog, (Shh) and continuous...

The pattern of feather buds in a tract is thought to result from the relative ratios between activator and inhibitor signals through a lateral inhibition process. We analyse the role of Drm/Gremlin, a BMPs antagonist expressed during feather pattern formation, in the dermal precursor, the dense dermis, the interbud dermis and in the posterior dermal condensation. We have altered the activity of...