Proteases of haematophagous arthropod vectors are involved in blood-feeding, yolk formation and immunity : a review

Ticks, triatomines, mosquitoes and sand flies comprise a large number of haematophagous arthropods considered vectors of human infectious diseases. While consuming blood to obtain the nutrients necessary to carry on life functions, these insects can transmit pathogenic microorganisms to the vertebrate host. Among the molecules related to the blood-feeding habit, proteases play an essential role. In this review, we provide a panorama of proteases from arthropod vectors involved in haematophagy, in digestion, in egg development and in immunity. As these molecules act in central biological processes, proteases from haematophagous vectors of infectious diseases may influence vector competence to transmit pathogens to their prey, and thus could be valuable targets for vectorial control

Sensitivity of carbon gas fluxes to weather variability on pristine, drained and rewetted temperate bogs

Climate change is considered to alter the functioning of boreal peatland ecosystems, but the vulnerability of pristine, rewetted and drained peatlands to climate change in temperate regions is unknown. We measured carbon (C) gas exchange during wet (2009) and dry (2010) growing periods in pristine, drained and rewetted sites in mountain bogs in the Bohemian Forest (Czech Republic). Wetter lawns with sedges and drier habitats dominated by ericaceous shrubs were distinguished and studied at each site. Methane (CH4) emissions, which decreased in the order pristine > rewetted > drained, were generally lower during the 2010 growing period than in 2009 as a consequence of a drought. During the drought in 2010, photosynthesis (PG) in the drier habitats with shrub vegetation increased on pristine and rewetted sites, while total respiration (RECO) remained the same. Communities dominated by sedges maintained similar rates of PG and RECO during both growing periods. Generally, this led to higher C accumulation during the drought on pristine and rewetted bogs. At the drained bog site, the decreased water table (WT) during the drought led to increased PG and RECO, such that the net C accumulation was similar in the two years. Drained peatlands may be more threatened by future climate change than pristine or rewetted peatlands because of their limited buffering capacity for decreased WT. In the case of further decreases in WT, they could lose the peatland vegetation and functions that have partly persisted through decades of drainage

Nanostructured carbon formation in IR laser-induced dielectric breakdown in benzene

XXI Reunión Nacional de Espectroscopia. V Congreso Ibérico de Espectroscopia, Murcia, 9-11 de Septiembre de 2008Peer Reviewe

Minor C-geranylated flavanones from Paulownia tomentosa fruits with MRSA antibacterial activity

Exhaustive chromatographic separation of the chloroform portion of the ethanolic extract obtained from Paulownia tomentosa (Thunb). Steud. (Paulowniaceae) fruits has led to isolation of ten C-6 geranylated flavanones tomentodiplacone C-I and mimulone C-E, featured by 3′-methoxy and 4′-hydroxy or 4′-hydroxy substitution of the B-ring of the flavonoid, respectively. The structures of these compounds were determined by using mass spectrometry (including HRMS) and 1D and 2D NMR spectroscopy. The absolute configurations of the compounds at C-2 were determined using circular dichroism. The obtained compounds showed the presence of a geranyl moiety functionalized by a carbonyl, hydroxyl or methoxyl group, or by formation of tetrahydrofuran or fused-pyrane ring, respectively. All of the flavanones described were isolated for the first time from a natural source. The antibacterial activities of selected compounds isolated along with the previously isolated geranylated flavanones were evaluated against a common panel of microbes and MRSA strains. The selected isolated compounds were tested for their ability to affect eukaryotic translation initiation via dual-luciferase reporter assay (firefly and renilla). © 2012 Elsevier Ltd. All rights reserved