The spectral evolution of three photoactive proteins has been investigated by measuring the fluorescence with good temporal and wavelength resolution and a high signal-to-noise ratio. Upon excitation at 400 nm wild-type (wt) PYP both at neutral pH and in the low-pH blueshifted pBdark state exhibited a strong quenching of the fluorescence, the major part of which could be described by lifetimes ...

Starting from a no-dynamic-arbitrage principle that imposes that trading costs should be non-negative on average and a simple model for the evolution of market prices, we demonstrate a relationship between the shape of the market impact function describing the average response of the market price to traded quantity and the function that describes the decay of market impact. In particular, we sh...

The concept of a spirally wrapped cell membrane as the mode of origin of the myelin sheath has made it difficult to explain (a) myelin sheath adjustment to growth of the axon in diameter and length, (b) the herniation and implied flexibility of the myelin sheath observed in normal fibers (1), (c) the ability of myelinated axons in tissue culture to lose and regain myelin in relatively rapid res...