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

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

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

Dosage de cannabinoïdes dans les fluides biologiques par GC-MS

Ce travail, en collaboration avec le laboratoire de toxicologie de l’hôpital Cantonal de Sion, a deux objectifs. 1. Le développement et la validation d’une méthode de quantification du cannabidiol et du cannabigerol dans le sang complet par GC-MS. 2. Montrer la spécificité et la sensibilité des tests à écoulement latéral Nal von Minden concernant le cannabis pour l’étude Faber

The XMM-Newton Optical Monitor Survey of the Taurus Molecular Cloud

The Optical Monitor (OM) on-board XMM-Newton obtained optical/ultraviolet data for the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST), simultaneously with the X-ray detectors. With the XEST OM data, we aim to study the optical and ultraviolet properties of TMC members, and to do correlative studies between the X-ray and OM light curves. In particular, we aim to determine whether accretion plays a significant role in the optical/ultraviolet and X-ray emissions. The Neupert effect in stellar flares is also investigated. Coordinates, average count rates and magnitudes were extracted from OM images, together with light curves with low time resolution (a few kiloseconds). For a few sources, OM FAST mode data were also available, and we extracted OM light curves with high time resolution. The OM data were correlated with Two Micron All Sky Survey (2MASS) data and with the XEST catalogue in the X-rays. The XEST OM catalogue contains 2,148 entries of which 1,893 have 2MASS counterparts. However, only 98 entries have X-ray counterparts, of which 51 of them are known TMC members and 12 additional are TMC candidates. The OM data indicate that accreting stars are statistically brighter in the U band than non-accreting stars after correction for extinction, and have U-band excesses, most likely due to accretion. The OM emission of accreting stars is variable, probably due to accretion spots, but it does not correlate with the X-ray light curve, suggesting that accretion does not contribute significantly to the X-ray emission of most accreting stars. In some cases, flares were detected in both X-ray and OM light curves and followed a Neupert effect pattern, in which the optical/ultraviolet emission precedes the X-ray emission of a flare, whereas the X-ray flux is proportional to the integral of the optical flux.Comment: Accepted by A&A, to appear in a special section/issue dedicated to the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST). Version with higher resolution figures available at this http://www.issibern.ch/teams/Taurus/papers.htm

Generación de D-xilosa por tratamiento hidrotérmico de endocarpios de aceitunas e hidrólisis enzimática de los oligosacáridos

Se ha desarrollado un procedimiento para obtener altas concentraciones de D-xilosa partiendo de huesos fragmentados de aceituna, un material abundante en los paises del sur de Europa. El esquema operativo consistió en el tratamiento de la materia prima con agua caliente a presión (ensayando temperaturas máximas entre 195 y 225ºC, y relaciones sólido/líquido entre 1/8 y 1/3), seguido de la hidrólisis enzimática del licor con celulasas, hemicelulasas y   β-glucosidasas. En la primera etapa, el trabajo a 210ºC maximizó el rendimiento de oligosacaridos en el licor (16,9 kg/100 kg materia prima) con una baja producción del inhibidor fermentativo HMF (0,25 kg/100kg materia prima). Posteriormente, la acción sinérgica de hemicelulasas y   β-glucosidasas generó la mayor cantidad de D-xilosa por hidrólisis de los oligómeros. En ese contexto, y para cargas de hemicelulasas de hasta 500 U/g, se alcanzaron rendimientos de 23,4 kg de D-xilosa, 0,63 kg de L-arabinosa y 0,21 kg de D-galactosa a partir de 100kg de endocarpios de aceituna