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pproximately half of human-induced carbon dioxide (CO) emissions are taken up by the land and ocean, and the rest stays in the atmosphere, increasing the global concentration and acting as a major greenhouse-gas (GHG) climate-forcing element. Although GHG mitigation is now in the political arena, the exact spatial distribution of the land sink is not well known. In this paper, an estimation of mean European net ecosystem exchange (NEE) carbon fluxes for the period 1998-2001 is performed with three mesoscale and two global transport models, based on the integration of atmospheric CO measurements into the same Bayesian synthesis inverse approach. A special focus is given to sub-continental regions of Europe making use of newly available CO concentration measurements in this region. Inverse flux estimates from the five transport models are compared with independent flux estimates from four ecosystem models. All inversions detect a strong annual carbon sink in the southwestern part of Europe and a source in the northeastern part. Such a dipole, although robust with respect to the network of stations used, remains uncertain and still to be confirmed with independent estimates. Comparison of the seasonal variations of the inversion-based net land biosphere fluxes (NEP) with the NEP predicted by the ecosystem models indicates a shift of the maximum uptake period, from June in the ecosystem models to July in the inversions. This study thus improves on the understanding of the carbon cycle at sub-continental scales over Europe, demonstrating that the methodology for understanding regional carbon cycle is advancing, which increases its relevance in terms of issues related to regional mitigation policies. [ABSTRACT FROM AUTHOR]

Mass spectra of the derivatives of indol-3yl-acetic acid and cis-abscisic acid were obtained in electron impact and chemical ionization positive ion and negative ion modes. The respective merits of methane, isobutane, and ammonia as reagent gases for structure determination and sensitive detection were compared using the methyl esters. From one to 10 fluorine atoms were attached to IAA to improve the electron-capturing properties of the molecule. The best qualitative information was obtained when using positive ion chemical ionization with methane. However, the most sensitive detection, with at least two ions per molecule, was achieved by electron impact on the IAA-HFB-ME derivative and by negative ion chemical ionization with NH on the ABA-methyl ester derivative. p ]Quantitative analyses of ABA in different parts of maize ( Zea mays cv. LG 11) root tips were performed by the latter technique. It was found that the cap and apex contained less ABA than the physiologically older parts of the root such as the elongation zone and the more differentiated tissues. This technique was also used to show a relation between maize root growth and the endogenous ABA level of the elongation zone and root tip: there is more ABA in the slowly growing roots than in the rapidly growing ones. [ABSTRACT FROM AUTHOR]

Quantitative analyses of abscisic acid (ABA) in different parts of maize root tips ( Zea mays L. cv. Kelvedon 33) were performed by mass fragmentography using the hexadeuterated analog of ABA as internal standard. It was found that the cap and the apex contained 36.1 μg and 66.5 μg ABA kg fresh weight, respectively. The possibility that the growth regulator formed in the cap and inhibiting the elongation of the extending zone of the root is ABA is discussed. [ABSTRACT FROM AUTHOR]

In a case where a 32-year-old man lost control of his vehicle, urine and blood samples were taken 6 h after the crash for toxicological investigations. In the hospital, the driver admitted consumption of some drugs, in particular digoxin and midazolam just before the crash which corresponded to the results of blood analyses. Toxicological findings indicated the presence of digoxin at 12.9 ng/ml and midazolam at 7 ng/ml in the blood. These results suggested that at the moment of the crash digoxin and midazolam blood levels were in the range of toxic and therapeutic concentrations, respectively. Therefore the respective roles of the drugs in the impairment of the ability to drive at the moment of the crash is discussed. [ABSTRACT FROM AUTHOR]