The importance of biomass net uptake for a trace metal budget in a forest stand in north-eastern France

The trace metal (TM: Cd, Cu, Ni, Pb and Zn) budget (stocks and annual fluxes) was evaluated in a forest stand (silver fir, Abies alba Miller) in north-eastern France. Trace metal concentrations were measured in different tree compartments in order to assess TM partitioning and dynamics in the trees. Inputs included bulk deposition, estimated dry deposition and weathering. Outputs were leaching and biomass exportation. Atmospheric deposition was the main input flux. The estimated dry deposition accounted for about 40% of the total trace metal deposition. The relative importance of leaching (estimated by a lumped parameter water balance model, BILJOU) and net biomass uptake (harvesting) for ecosystem exportation depended on the element. Trace metal distribution between tree compartments (stem wood and bark, branches and needles) indicated that Pb was mainly stored in the stem, whereas Zn and Ni, and to a lesser extent Cd and Cu, were translocated to aerial parts of the trees and cycled in the ecosystem. For Zn and Ni, leaching was the main output flux (N95% of the total output) and the plot budget (input–output) was negative, whereas for Pb the biomass net exportation represented 60% of the outputs and the budget was balanced. Cadmium and Cu had intermediate behaviours, with 18% and 30% of the total output relative to biomass exportation, respectively, and the budgets were negative. The net uptake by biomass was particularly important for Pb budgets, less so for Cd and Cu and not very important for Zn and Ni in such forest stands

Pulse shaping with birefringent crystals: a tool for quantum metrology

A method for time differentiation based on a Babinet-Soleil-Bravais compensator is introduced. The complex transfer function of the device is measured using polarization spectral interferometry. Time differentiation of both the pulse field and pulse envelope are demonstrated over a spectral width of about 100 THz with a measured overlap with the objective mode greater than 99.8%. This pulse shaping technique is shown to be perfectly suited to time metrology at the quantum limit

Industrial Policy in Chile

This paper studies three horizontal policy instruments and two vertical ones in Chilean industrial policy, particularly regarding small and medium enterprises (SMEs). The horizontal instruments are (1) a guarantee program for borrowing by SMEs (FOGAPE), (2) a small subsidy to new exports that was applied from 1985 through 2003, and (3) the innovation subsidies provided by the Corporación de Fomento de la Producción (CORFO). The vertical policy instruments are the activities of Fundación Chile (FCh), a semi-public entrepreneur cum venture capitalist, and a CORFO program to attract foreign direct investment in information technology. Although most programs are well designed, they are numerous and insufficiently funded; Chile could benefit from a prioritization of needs and consolidation of these programs. Moreover, the instruments for making strategic bets on new sectors are particularly weak. In particular, FCh needs to refocus its activities on high-risk projects with long payoffs, something it cannot do with its small endowment.Industrial policy, Small and medium enterprises, Chile