Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations

13 págs.; 7 figs.; 8 tabs.© 2015 AIP Publishing LLC. The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5-10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.F.F.S. and P.L.V. acknowledge the Portuguese Foundation for Science and Technology (FCT-MEC) through Grant Nos. SFRH/BPD/68979/2010 and SFRH/BSAB/105792/2014, respectively, the research Grant Nos. PTDC/FIS-ATO/1832/ 2012 and UID/FIS/00068/2013. P.L.V. also acknowledges his Visiting Research Fellow position at Flinders University, Adelaide, South Australia. The Patrimoine of the University of Liège, the Fonds National de la Recherche Scientifique, and the Fonds de la Recherche Fondamentale Collective of Belgium have also supported this research. E.L. and R.F.C.N. thank CNPq (Brazil) and the Science Without Borders Programme for opportunities to study abroad. The authors wish to acknowledge the beam time at the ISA synchrotron at Aarhus University, Denmark. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (Grant No. FP7/2007-2013) CALIPSO under Grant Agreement No. 312284. D.B.J. thanks the Australian Research Council for financial support provided through a Discovery Early Career Research Award. M.J.B. also thanks the Australian Research Council for some financial support, while M.J.B. and M.C.A.L. acknowledge the Brazilian agencies CNPq and FAPEMIG for financial support. F.B. and G.G. acknowledge partial financial support from the Spanish Ministry MINECO (Project No. FIS2012-31230) and the EU COST Action No. CM1301 (CELINA). Finally, R.F.C., M.T.do N.V., M.H.F.B., and M.A.P.L. acknowledge support from the Brazilian agency CNPq.Peer Reviewe

Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.

The São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity

Seismic structure across the rift valley of the Mid-Atlantic Ridge at 23°20′ (MARK area): Implications for crustal accretion processes at slow spreading ridges

International audienc