13 research outputs found

    Structural study of Cu 2− x

    No full text

    Laser spectroscopic electric field measurement in krypton

    No full text
    A laser spectroscopic method for sensitive electric field measurements using krypton has been developed. The Stark effect of high Rydberg states of the krypton autoionizing series can be measured by a technique called fluorescence dip spectroscopy (FDS) with high spatial and temporal resolution. Calibration measurements have been performed in a reference cell with known electric field and they agree very well with numerical solutions of Schrodinger's equation for jl-coupled states. The application of this method has been demonstrated in the sheath region of a capacitively coupled radiofrequency (RF) discharge. The laser spectroscopic method allows us to add krypton as a small admixture to various low temperature plasmas

    Sub-micron level investigation reveals the inaccessibility of stabilized carbon in soil microaggregates

    Get PDF
    Abstract Direct evidence-based approaches are vital to evaluating newly proposed theories on the persistence of soil organic carbon and establishing the contributions of abiotic and biotic controls. Our primary goal was to directly identify the mechanisms of organic carbon stabilization in native-state, free soil microaggregates without disrupting the aggregate microstructure using scanning transmission x-ray microscopy coupled with near edge x-ray absorption fine structure spectroscopy (STXM-NEXAFS). The influence of soil management practices on microaggregate associated-carbon was also assessed. Free, stable soil microaggregates were collected from a tropical agro-ecosystem in Cruz Alta, Brazil. The long-term experimental plots (>25 years) comparing two tillage systems: no-till and till with a complex crop rotation. Based on simultaneously collected multi-elemental associations and speciation, STXM-NEXAFS successfully provided submicron level information on organo-mineral associations. Simple organic carbon sources were found preserved within microaggregates; some still possessing original morphology, suggesting that their stabilization was not entirely governed by the substrate chemistry. Bulk analysis showed higher and younger organic carbon in microaggregates from no-till systems than tilled systems. These results provide direct submicron level evidence that the surrounding environment is involved in stabilizing organic carbon, thus favoring newly proposed concepts on the persistence of soil organic carbon

    Genetic factors affecting EBV copy number in lymphoblastoid cell lines derived from the 1000 Genome Project samples

    No full text
    Epstein-Barr virus (EBV), human herpes virus 4, has been classically associated with infectious mononucleosis, multiple sclerosis and several types of cancers. Many of these diseases show marked geographical differences in prevalence, which points to underlying genetic and/or environmental factors. Those factors may include a different susceptibility to EBV infection and viral copy number among human populations. Since EBV is commonly used to transform B-cells into lymphoblastoid cell lines (LCLs) we hypothesize that differences in EBV copy number among individual LCLs may reflect differential susceptibility to EBV infection. To test this hypothesis, we retrieved whole-genome sequenced EBV-mapping reads from 1,753 LCL samples derived from 19 populations worldwide that were sequenced within the context of the 1000 Genomes Project. An in silico methodology was developed to estimate the number of EBV copy number in LCLs and validated these estimations by real-time PCR. After experimentally confirming that EBV relative copy number remains stable over cell passages, we performed a genome wide association analysis (GWAS) to try detecting genetic variants of the host that may be associated with EBV copy number. Our GWAS has yielded several genomic regions suggestively associated with the number of EBV genomes per cell in LCLs, unraveling promising candidate genes such as CAND1, a known inhibitor of EBV replication. While this GWAS does not unequivocally establish the degree to which genetic makeup of individuals determine viral levels within their derived LCLs, for which a larger sample size will be needed, it potentially highlighted human genes affecting EBV-related processes, which constitute interesting candidates to follow up in the context of EBV related pathologiesThis work was supported by Instituto de Salud Carlos III (ES) (RD07/0060); Spanish Government Grants (BFU2012-38236); Departament d'Innovació, Universitats I Empresa, Generalitat de Catalunya (2014SGR1311); Instituto de Salud Carlos III (PT13/0001/0026); FEDER (Fondo Europeo de Desarrollo Regional)/FSE (Fondo Social Europeo)
    corecore