Multimodal principal component analysis to identify major features of white matter structure and links to reading

The role of white matter in reading has been established by diffusion tensor imaging (DTI), but DTI cannot identify specific microstructural features driving these relationships. Neurite orientation dispersion and density imaging (NODDI), inhomogeneous magnetization transfer (ihMT) and multicomponent driven equilibrium single-pulse observation of T1/T2 (mcDESPOT) can be used to link more specific aspects of white matter microstructure and reading due to their sensitivity to axonal packing and fiber coherence (NODDI) and myelin (ihMT and mcDESPOT). We applied principal component analysis (PCA) to combine DTI, NODDI, ihMT and mcDESPOT measures (10 in total), identify major features of white matter structure, and link these features to both reading and age. Analysis was performed for nine reading-related tracts in 46 neurotypical 6–16 year olds. We identified three principal components (PCs) which explained 79.5% of variance in our dataset. PC1 probed tissue complexity, PC2 described myelin and axonal packing, while PC3 was related to axonal diameter. Mixed effects regression models did not identify any significant relationships between principal components and reading skill. Bayes factor analysis revealed that the absence of relationships was not due to low power. Increasing PC1 in the left arcuate fasciculus with age suggest increases in tissue complexity, while increases of PC2 in the bilateral arcuate, inferior longitudinal, inferior fronto-occipital fasciculi, and splenium suggest increases in myelin and axonal packing with age. Multimodal white matter imaging and PCA provide microstructurally informative, powerful principal components which can be used by future studies of development and cognition. Our findings suggest major features of white matter undergo development during childhood and adolescence, but changes are not linked to reading during this period in our typically-developing sample

Enhancing multi-scale Mekong water governance

The CPWF Project PN50 “Enhancing multi-scale water governance” was a flagship activity of the Mekong Program on Water, Environment Resilience (M-POWER). The goal of helping improve livelihood security, human and ecosystem health in the Mekong Region through democratizing water governance was pursued through critical research and direct engagement with stakeholders involved in managing floods, irrigation, hydropower, watersheds, fisheries and urban water works at various scales. We identified commons governance problems and suggested ways that some can be addressed. Often, for example, there are needs to: strengthen local representation, improve the quality of deliberative processes, enhance the interplay between institutions at different levels, and build capacities to handle uncertainties and adapt to changes in flow regimes

Chlorido(η4-1,5-cyclo­octa­diene)[(penta­fluoro­eth­yl)diphenyl­phosphane]iridium(I)

The title structure,[IrCl(C8H12)(C14H10F5P)], reveals that (C2F5)PPh2 (penta­fluoro­ethyl­diphenyl­phosphane or pfepp) disrupts the iridium dimer [(cod)IrCl]2 (cod = cyclo­octa-1,5-diene) by rupturing the bridging chloride ligands and binding in the open coordination site to form (cod)Ir(pfepp)Cl with the IrI atom in a distorted square-planar coordination environment. The structure deviates very little from the IrI–triphenyl­phosphine analog, although a significantly (∼20σ) shorter Ir—P bond is noted for the title compound

Effects of fluoride on primary cultured haemocytes from the marine gastropod Haliotis tuberculata

International audienceAs a consequence of human's activities, fluoride concentration in many aquatic ecosystems is significantly increasing. Nevertheless, little is known about fluoride toxicity to aquatic life. In this study the effect of exposure to different concentrations of sodium fluoride (2, 10, 50, 250 and 1,250 μg mL −1) during 24 h on primary cultured haemocytes of the gastropod Haliotis tuberculata was realized. Results indicate no significant effect of NaF on cell viability, Lysosomal membrane stability, phagocytosis and ROS production at concentrations of 2, 10, 50 and 250 μg mL −1. Nevertheless, lysosomal membrane alterations, a decrease of phagocytosis and morphological changes of H. tuberculata haemocytes were observed at concentration of 1,250 µg mL −1 NaF suggesting a potential impact of NaF at high concentration in the environment