An Environment Adaptive Practical Packet Scheduling Algorithm with Single User Fairness Guarantee over the Forward Link of 3G Cellular Data Services

Aluminum castings can contain pinholes caused by porosity from a number of sources, including the presence of gas or from shrinkage. These pinholes, although normally small in size and number, can greatly influence the properties of the casting, often resulting in the scrapping of the part. While many factors are involved in the formation of porosity in aluminum castings, such as the influences of hydrogen and aluminum oxide (A12O3) on gas-porosity, this study investigates the effects of cooling rate and section thickness. These factors are studied by using a sand cast aluminum bar with different section thicknesses which undergo different cooling rates during casting [1,2]

Evolution of chalcone isomerase from a noncatalytic ancestor

The emergence of catalysis in a noncatalytic protein scaffold is a rare, unexplored event. Chalcone isomerase (CHI), a key enzyme in plant flavonoid biosynthesis, is presumed to have evolved from a nonenzymatic ancestor related to the widely distributed fatty-acid binding proteins (FAPs) and a plant protein family with no isomerase activity (CHILs). Ancestral inference supported the evolution of CHI from a protein lacking isomerase activity. Further, we identified four alternative founder mutations, i.e., mutations that individually instated activity, including a mutation that is not phylogenetically traceable. Despite strong epistasis in other cases of protein evolution, CHI's laboratory reconstructed mutational trajectory shows weak epistasis. Thus, enantioselective CHI activity could readily emerge despite a catalytically inactive starting point. Accordingly, X-ray crystallography, NMR, and molecular dynamics simulations reveal reshaping of the active site toward a productive substrate-binding mode and repositioning of the catalytic arginine that was inherited from the ancestral fatty-acid binding proteins