Does the Integration of Haptic and Visual Cues Reduce the Effect of a Biased Visual Reference Frame on the Subjective Head Orientation?

The selection of appropriate frames of reference (FOR) is a key factor in the elaboration of spatial perception and the production of robust interaction with our environment. The extent to which we perceive the head axis orientation (subjective head orientation, SHO) with both accuracy and precision likely contributes to the efficiency of these spatial interactions. A first goal of this study was to investigate the relative contribution of both the visual and egocentric FOR (centre-of-mass) in the SHO processing. A second goal was to investigate humans' ability to process SHO in various sensory response modalities (visual, haptic and visuo-haptic), and the way they modify the reliance to either the visual or egocentric FORs. A third goal was to question whether subjects combined visual and haptic cues optimally to increase SHO certainty and to decrease the FORs disruption effect.Thirteen subjects were asked to indicate their SHO while the visual and/or egocentric FORs were deviated. Four results emerged from our study. First, visual rod settings to SHO were altered by the tilted visual frame but not by the egocentric FOR alteration, whereas no haptic settings alteration was observed whether due to the egocentric FOR alteration or the tilted visual frame. These results are modulated by individual analysis. Second, visual and egocentric FOR dependency appear to be negatively correlated. Third, the response modality enrichment appears to improve SHO. Fourth, several combination rules of the visuo-haptic cues such as the Maximum Likelihood Estimation (MLE), Winner-Take-All (WTA) or Unweighted Mean (UWM) rule seem to account for SHO improvements. However, the UWM rule seems to best account for the improvement of visuo-haptic estimates, especially in situations with high FOR incongruence. Finally, the data also indicated that FOR reliance resulted from the application of UWM rule. This was observed more particularly, in the visual dependent subject. Conclusions: Taken together, these findings emphasize the importance of identifying individual spatial FOR preferences to assess the efficiency of our interaction with the environment whilst performing spatial tasks

Identification of Keratinocyte Growth Factor as a Target of microRNA-155 in Lung Fibroblasts: Implication in Epithelial-Mesenchymal Interactions

International audienceBACKGROUND: Epithelial-mesenchymal interactions are critical in regulating many aspects of vertebrate embryo development, and for the maintenance of homeostatic equilibrium in adult tissues. The interactions between epithelium and mesenchyme are believed to be mediated by paracrine signals such as cytokines and extracellular matrix components secreted from fibroblasts that affect adjacent epithelia. In this study, we sought to identify the repertoire of microRNAs (miRNAs) in normal lung human fibroblasts and their potential regulation by the cytokines TNF-alpha, IL-1beta and TGF-beta. METHODOLOGY/PRINCIPAL FINDINGS: MiR-155 was significantly induced by inflammatory cytokines TNF-alpha and IL-1beta while it was down-regulated by TGF-beta. Ectopic expression of miR-155 in human fibroblasts induced modulation of a large set of genes related to "cell to cell signalling", "cell morphology" and "cellular movement". This was consistent with an induction of caspase-3 activity and with an increase in cell migration in fibroblasts tranfected with miR-155. Using different miRNA bioinformatic target prediction tools, we found a specific enrichment for miR-155 predicted targets among the population of down-regulated transcripts. Among fibroblast-selective targets, one interesting hit was keratinocyte growth factor (KGF, FGF-7), a member of the fibroblast growth factor (FGF) family, which owns two potential binding sites for miR-155 in its 3'-UTR. Luciferase assays experimentally validated that miR-155 can efficiently target KGF 3'-UTR. Site-directed mutagenesis revealed that only one out of the 2 potential sites was truly functional. Functional in vitro assays experimentally validated that miR-155 can efficiently target KGF 3'-UTR. Furthermore, in vivo experiments using a mouse model of lung fibrosis showed that miR-155 expression level was correlated with the degree of lung fibrosis. CONCLUSIONS/SIGNIFICANCE: Our results strongly suggest a physiological function of miR-155 in lung fibroblasts. Altogether, this study implicates this miRNA in the regulation by mesenchymal cells of surrounding lung epithelium, making it a potential key player during tissue injury

Evaluation de la dureté des blés : Analyse globale ou grain par grain

7 tables 8 graph.National audienc

Synthesis of oxygenated compounds from methane, carbon dioxide and liquid water using non-thermal plasma

Oxygenated compounds were obtained from methane and carbon dioxide using the unconventional activation by dielectric barrier discharge plasma. The process was performed using a multiphase feed composed of methane, liquid water and carbon dioxide as oxidizing agent. The effect of the CH4/CO2 ratio as well as the flow of liquid water were investigated. The results show that the presence of liquid water in the reactor favors the formation of oxygenated compounds. A direct proportional relation between the flow of water, concentration of methane in the gaseous feed (in the presence of water) and the amount of the produced oxygenates was observed. The highest value of selectivity towards oxygenated compounds was 21.2%, with methanol and formic acid being the main products formed

Formation of amines: hydrogenation of nitrile and isonitrile as selective routes in the interstellar medium

Context. Beyond NH3, only one primary alkylamine, CH3NH2, has been identified in the interstellar medium and the reason why is still not understood: its formation could occur in the gas phase or in icy environments. Aims. To consider any possible difference between the formation of primary and secondary amines, we studied the hydrogenation processes of CH3CN and CH3NC, which would lead to the simple primary CH3CH2NH2 and secondary CH3NHCH3 amines, respectively. Methods. Experimentally, the hydrogenation of CH3CN and CH3NC was carried out under ultra-high vacuum, using two beamlines to inject the nitrile/isonitrile and H onto substrate surfaces of gold or water ice. The reactions were monitored using infrared spectroscopy and the products were followed by mass spectrometry. Theoretically, the energetics of the hydrogenation paths were determined using the M06-2X functional after benchmarking against post Hartree-Fock procedures. Meanwhile, a survey of the high-mass star forming region W51/e2 has been performed. Results. Following co-deposition of CH3CN and H, we show that these species do not react together between 10 and 60 K. For CH3NC we found that the hydrogenation process works all the way through the CH3NHCH3 end product; we also identified the CH3NCH2 intermediate together with side products, CH4 and HCN, showing that the isonitrile backbone is breaking. These results are consistent with the calculations of a high barrier on the first hydrogenation step for CH3CN and a lower barrier for CH3NC. Conclusions. The formation of CH3CH2NH2 by hydrogenation of CH3CN appears rather unlikely in both the gas phase and ice environment whereas that of CH3NHCH3 is a clear possibility. The limiting factor appears to be the efficiency of the tunneling effect through the first activation barrier on the reaction paths. More surveys are required for further insight into the search for amines

Investigation of Young water inflow in karst aquifers using SF6-CFC-3H/He-85Kr-39Ar and stable isotope components

International audienc