Ultrafast pulse shaping modulates perceived visual brightness in living animals

Vision is usually assumed to be sensitive to the light intensity and spectrum but not to its spectral phase. However, experiments performed on retinal proteins in solution showed that the first step of vision consists in an ultrafast photoisomerization that can be coherently controlled by shaping the phase of femtosecond laser pulses, especially in the multiphoton interaction regime. The link between these experiments in solution and the biological process allowing vision was not demonstrated. Here, we measure the electric signals fired from the retina of living mice upon femtosecond multipulse and single-pulse light stimulation. Our results show that the electrophysiological signaling is sensitive to the manipulation of the light excitation on a femtosecond time scale. The mechanism relies on multiple interactions with the light pulses close to the conical intersection, like pump-dump (photoisomerization interruption) and pump-repump (reverse isomerization) processes. This interpretation is supported both experimentally and by dynamics simulations

Exports and Property Prices in France: Are They Connected?

We argue that resource reallocation from the exporting to the construction sector triggered by fast rising property prices hindered France to meet world export demand vis-à-vis its products. Our econometric analysis shows that the resource reallocation argument helps explain French export performance between the early 2000s and 2007, unexplained by traditional models. This result is confirmed for a set of OECD countries that experienced a marked decline in their export performance and sustained realestate boom after 2000.http://deepblue.lib.umich.edu/bitstream/2027.42/132997/1/wp985.pd