The Cenozoic evolution of the Roer Valley Rift System integrated at a European scale

International audienceThe Roer Valley Rift System (RVRS) is located between the West European rift and the North Sea rift system. During the Cenozoic, the RVRS was characterized by several periods of subsidence and inversion, which are linked to the evolution of the adjacent rift systems. Combination of subsidence analysis and results from the analysis of thickness distributions and fault systems allows the determination of the Cenozoic evolution and quantification of the subsidence. During the Early Paleocene, the RVRS was inverted (Laramide phase). The backstripping method shows that the RVRS was subsequently mainly affected by two periods of subsidence, during the Late Paleocene and the Oligocene–Quaternary time intervals, separated by an inversion phase during the Late Eocene. During the Oligocene and Miocene periods, the thickness of the sediments and the distribution of the active faults reveal a radical rotation of the direction of extension by about 70–80j (counter clockwise). Integration of these results at a European scale indicates that the Late Paleocene subsidence was related to the evolution of the North Sea basins, whereas the Oligocene–Quaternary subsidence is connected to the West European rift evolution. The distribution of the inverted provinces also shows that the Early Paleocene inversion (Laramide phase) has affected the whole European crust, whereas the Late Eocene inversion was restricted to the southern North Sea basins and the Channel area. Finally, comparison of these deformations in the European crust with the evolution of the Alpine chain suggests that the formation of the Alps has controlled the evolution of the European crust since the beginning of the Cenozoic

Increased mitochondrial calcium levels associated with neuronal death in a mouse model of Alzheimer's disease

Mitochondria contribute to shape intraneuronal Ca2+ signals. Excessive Ca2+ taken up by mitochondria could lead to cell death. Amyloid beta (A beta) causes cytosolic Ca2+ overload, but the effects of A beta on mitochondrial Ca2+ levels in Alzheimer's disease (AD) remain unclear. Using a ratiometric Ca2+ indicator targeted to neuronal mitochondria and intravital multiphoton microscopy, we find increased mitochondrial Ca2+ levels associated with plaque deposition and neuronal death in a transgenic mouse model of cerebral beta -amyloidosis. Naturally secreted soluble A beta applied onto the healthy brain increases Ca2+ concentration in mitochondria, which is prevented by blockage of the mitochondrial calcium uniporter. RNA-sequencing from post-mortem AD human brains shows downregulation in the expression of mitochondrial influx Ca2+ transporter genes, but upregulation in the genes related to mitochondrial Ca2+ efflux pathways, suggesting a counteracting effect to avoid Ca2+ overload. We propose lowering neuronal mitochondrial Ca2+ by inhibiting the mitochondrial Ca2+ uniporter as a novel potential therapeutic target against AD. Calvo-Rodriguez et al. show elevated calcium levels in neuronal mitochondria in a mouse model of cerebral beta -amyloidosis after plaque deposition, which precede rare neuron death events in this model. The mechanism involves toxic extracellular A beta oligomers and the mitochondrial calcium uniporter

Identification of Copy Number Variants Defining Genomic Differences among Major Human Groups

BACKGROUND:Understanding the genetic contribution to phenotype variation of human groups is necessary to elucidate differences in disease predisposition and response to pharmaceutical treatments in different human populations. METHODOLOGY/PRINCIPAL FINDINGS:We have investigated the genome-wide profile of structural variation on pooled samples from the three populations studied in the HapMap project by comparative genome hybridization (CGH) in different array platforms. We have identified and experimentally validated 33 genomic loci that show significant copy number differences from one population to the other. Interestingly, we found an enrichment of genes related to environment adaptation (immune response, lipid metabolism and extracellular space) within these regions and the study of expression data revealed that more than half of the copy number variants (CNVs) translate into gene-expression differences among populations, suggesting that they could have functional consequences. In addition, the identification of single nucleotide polymorphisms (SNPs) that are in linkage disequilibrium with the copy number alleles allowed us to detect evidences of population differentiation and recent selection at the nucleotide variation level. CONCLUSIONS:Overall, our results provide a comprehensive view of relevant copy number changes that might play a role in phenotypic differences among major human populations, and generate a list of interesting candidates for future studies

The role of CO2-enhanced coalbed methane production in the global CCS strategy

Subsurface coal seams are generally considered as important potential geological media for underground storage of carbon dioxide, but this is a more complex option than other storage options. The required number of wells and the uncertainties due to the complexity were generally considered as main barriers and large-scale projects are hence pending after the initial pilot projects. However, CBM production is currently initiated in coal basins throughout the world, thereby providing more and more possibilities for application of storage of CO2 in coal in the future. Experience gained from other CCS projects will be essential In this paper, it is recommended that - if feasible - future coal storage projects should be developed with horizontal injection wells in a mature CBM field that has seen peak production of CBM. The possibility of using horizontal wells for injection in coal should be tested first. An integrated approach aiming at local benefits through small-scale electricity generation or re-use of production water could have an clear added value. © 2011 Published by Elsevier Ltd

High-pressure study of microcrystalline tungsten trioxide phase transitions by Raman spectroscopy

A high-pressure Raman study of microcrystalline tungsten oxide was performed in the 0.1 MPa-31 GPa pressure range under isostatic and non-isostatic conditions. The phase transitions, which take place below 0.1 GPa and at 22 GPa are first order, while two further structural changes, observed at about 3 and 10 GPa, are diffuse. Surprisingly, the non-isostatic conditions do not induce inhomogeneous band broadenings and do not modify the transitions sequence observed in isostatic conditions. Compressibility of the different phases is estimated from spectral data

Electrochemical and Raman study of La0.7Sr0.3Co0.8Fe0.2O3 (-) (delta) reduction

AIR:SURFACES+ABO:FGAThe reduction of La0.7Sr0.3Co0.8Fe0.2O3 (- delta) (LSCF7382) by heat-treatment in H-2 atmosphere or by electrochemical polarization has been followed by X-ray diffraction and Raman spectroscopy. The transition from perovskite ABO(3) to brownmillerite A(2)B(2)O(5) occurs at 250-300 degrees C in 10% H-2 atmosphere and is reversible. The Raman spectrum of brownmillerite shows two bands at 560 and 640 cm(-1) that we attribute to CoO4 tetrahedron stretching. Above 600 degrees C the sample starts to decompose irreversibly into Co, La2O3, SrO, and LaSrFeO4. This confirms that Co cations are more reducible than Fe ones. The Raman spectra obtained under cathodic polarization of the LSCF7382/CGO interface at 300 degrees C and PO2 = 10(-4) or 0.1 atm show the same bands as for the A(2)B(2)O(5) structure. This indicates that electrochemical reduction produces Co2+ in tetrahedral environment, even at low reducing overpotentials. Two reduction steps have been observed by linear sweep valtammetry and open circuit voltage relaxation. In both cases, Raman spectra indicate the presence of Co2+ in tetrahedral environment. The first reduction step is thus attributed to the reduction of B4+ within the perovskite phase and the second one to the reduction of Co3+ to Co2+ associated to the transition from perovskite to brownmillerite phase. Thermodynamic calculations from published literature support this idea. The association of n-type mobile species (Co2+) with oxygen vacancies is confirmed. (C) 2013 Elsevier B.V. All rights reserved