Suchergebnisse

Volatile isoprenoids produced by plants are emitted in vast quantities into the atmosphere, with substantial effects on global carbon cycling. Yet, the molecular mechanisms regulating the balance between volatile and non-volatile isoprenoid production remain unknown. Isoprenoids are synthesised via sequential condensation of isopentenyl pyrophosphate (IPP) to dimethylallyl pyrophosphate (DMAPP), with volatile isoprenoids containing fewer isopentenyl subunits. The DMAPP:IPP ratio could affect the balance between volatile and non-volatile isoprenoids, but the plastidic DMAPP:IPP ratio is generally believed to be similar across different species. Here we demonstrate that the ratio of DMAPP:IPP produced by hydroxymethylbutenyl diphosphate reductase (HDR/IspH), the final step of the plastidic isoprenoid production pathway, is not fixed. Instead, this ratio varies greatly across HDRs from phylogenetically distinct plants, correlating with isoprenoid production patterns. Our findings suggest that adaptation of HDR plays a previously unrecognised role in determining in vivo carbon availability for isoprenoid emissions, directly shaping global biosphere-atmosphere interactions. ; Research at the University of Queensland was funded by an Australian Research Council grant to LKN and CEV. Research at the Center for Biosustainability was supported by The Novo Nordisk Foundation under NFF grant number NNF10CC1016517. JPG was supported by a Marie Curie International outgoing Fellowship within the 7th European Community Framework Programme. CEV was supported by Queensland Government Smart Futures and Accelerate Fellowships. Metabolomics Australia is part of the Bioplatforms Australia network, funded through the Australian Government's National Collaborative Research Infrastructure Strategy (NCRIS). ; Peer reviewed

Resumen del documento en catalán ; El libro es una compilación cuatrilingüe (catalán, castellano, inglés y esperanto) que expone y explica los actos del movimiento contra el desfile militar en Barcelona del mes de Mayo del año 2000. El objetivo del libro es que pueda ayudar en otros lugares a iniciar acciones similares. ; Cataluña ; ESP

Resumen del documento en catalán ; El libro es una compilación cuatrilingüe (catalán, castellano, inglés y esperanto) que expone y explica los actos del movimiento contra el desfile militar en Barcelona del mes de Mayo del año 2000. El objetivo del libro es que pueda ayudar en otros lugares a iniciar acciones similares. ; Cataluña ; ESP

In the context of bilingual research, little is known about the effects of neurodegenerative disorders (NDs) on the processing of two languages in a bilingual. In a recent cross-sectional study, we showed that Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD) had similar effects on lexico-semantic processes in the two languages of highly proficient bilinguals (Costa et al., Neuropsychologia, 2012, 50, 740–53). In the present longitudinal study, we extend this finding by looking at the pattern of language deterioration over time in the same population of Catalan-Spanish bilingual patients. All the participants completed three language-processing tasks (picture naming, word translation and word comprehension), both in their dominant (L1) and non-dominant (L2) language. At one year, the final group was made up of 50 patients: 15 with MCI and 35 with AD. For AD but not MCI, the language deterioration over time was the same in both languages, as previously reported in the cross-sectional study. The results are discussed in the frame of the hypothesis of shared lexico-semantic processing in highly proficient bilinguals and the influence of executive control deficits in language production. ; This work was supported by grants from the Spanish Government (PSI2008-01191, PSI2011-23033, PSI2014-52210-P, Consolider Ingenio 2010CSD2007-00048), Catalan Government (2014SGR1210), La Marató-TVE Foundation (20141030-31) and European Research Council under the European Community's Seventh Framework (FP7/2007–2013 Cooperation grant agreement 613465-AThEME). MC was supported by a Ramón y Cajal postdoctoral fellowship from the Spanish Government. MH was supported by the postdoctoral fellowship 'Formación Posdoctoral' within the Spanish Government program 'Programa Estatal de Promoción del Talento y su Empleabilidad del Plan Estatal de Investigación Científica y Técnica y de Innovación 2013–2016'.

In this paper, the multipactor RF breakdown in a parallel-plate waveguide partially filled with a ferrite slab magnetized normal to the metallic plates is studied. An external magnetic field is applied along the vertical direction between the plates in order to magnetize the ferrite. Numerical simulations using an in-house 3D code are carried out to obtain the multipactor RF voltage threshold in this kind of structures. The presented results show that the multipactor RF voltage threshold at certain frequencies becomes considerably lower than for the corresponding classical metallic parallel-plate waveguide with the same vacuum gap. ; This work was supported by the European Space Agency (ESA) under Novel Investigation in Multipactor Effect in Ferrite and other Dielectrics used in high power RF Space Hardware Contract AO 1-7551/13/NL/GLC, and partially by the Spanish Government (under coordinated R&D projects TEC2013-47037-C5-R and TEC2014-55463-C3-3-P).