The bird feather vane can be separated into two parts by pulling the barbs apart. The original state can be re-established easily by lightly stroking through the feather. Hooklets responsible for holding vane barbs together are not damaged by multiple zipping and unzipping cycles. Because numerous microhooks keep the integrity of the feather, their properties are of great interest for understan...

Briefly, a feather is a semigroup derivation diagram with the labels on the edges removed. In this paper, we are concerned with possible definitions for the thickness of a feather. A major open problem is whether the word problem is solvable for semigroup presentations with one defining relation. It is known that word problems for semigroup presentations are solvable if the number of regions in...

Feathers are under-represented in the fossil record because soft tissues do not usually preserve well sedimentary sequences. Fossil feathers nevertheless extremely important resolving pattern and process related to origin of dinosaur flight. In recent years, a number have been discovered which mummified amber; these preserved three dimensions with remarkable sub-microscopic details especially f...

The identification of bird species from feather fragments is useful in many disciplines, including forensic science. Feather evidence can be helpful to criminal investigations in demonstrating physical contact between clothing manufactured with down feathers, or it may provide specific links to the crime scene by identifying the species or group of birds from which the feather evidence came. Th...

We report the mechanism of color production in peacock feathers. We find that the cortex in differently colored barbules, which contains a 2D photonic-crystal structure, is responsible for coloration. Simulations reveal that the photonic-crystal structure possesses a partial photonic bandgap along the direction normal to the cortex surface, for frequencies within which light is strongly reflect...

Proteases are catabolic enzymes that catalyze the complete hydrolysis of protein. They constitute one of the most important groups of industrial enzymes, accounting for nearly 60% of the total worldwide enzyme sale1. Keratinolytic protease is a specific protease that has immense commercial importance. It acts on keratin of the hides thus can be used in dehairing2. This enzyme along with proteas...

Rockets and Feathers? Petroleum Product Price Movements “Shooting up like a rocket, drifting downward like a feather in the wind,” or so goes the perception of petroleum product prices. This became the focus of public attention world over in 2008, when the international price of oil surged in the first six months, only to fall dramatically to a third of its peak value in the following five mont...

The ability to takeoff quickly and accelerate away from predators is crucial to bird survival. Crude oil can disrupt the fine structure and function of feathers, and here we tested for the first time how small amounts of oil on the trailing edges of the wings and tail of Western sandpipers (Calidris mauri) affected takeoff flight performance. In oiled birds, the distance travelled during the fi...