22 research outputs found

    Extreme precipitation in low mountain ranges in Central Europe: a comparative study between the Vosges and the Ore mountains

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    of the doctoral dissertation Extreme precipitation is related to flooding which is one of the most frequent natural hazards in Central Europe. Detailed understanding of extreme precipitation is the precondition for an efficient risk management and more precise projections of precipitation, which include uncertainties, especially at regional scale. The thesis focuses on extreme precipitation in the Ore Mountains (OM) and the Vosges Mountains (VG); two low mountain ranges in Central Europe experiencing orographic effect on precipitation. Based on state of the art about precipitation in OM and VG, a currently missing analysis of the temporal distribution of precipitation in VG was needed prior to the analysis of extremes. The original dataset of daily precipitation totals from 14 weather stations used in the initial study was extended to 168 stations covering a broader area of VG. The study of temporal distribution of precipitation during 1960-2013 led to a classification of stations: (i) mountainous stations with winter maxima and highest mean annual totals due to orographic enhancement of precipitation, (ii) stations on leeward slopes with two maxima (summer and winter), (iii) lee side stations with summer maxima and lowest mean annual totals due to rain shadow and more continental character, and..

    Conservation of eukaryotic transposon-defence mechanisms.

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    <p>(A) <i>T</i>. <i>spiralis</i> endo siRNAs align predominantly antisense to transposon sequence. (B) Anti-transposon endo siRNAs in <i>T</i>. <i>spiralis</i> have the characteristic 2 nt overhang of Dicer products. (C) CpG DNA methylation in <i>T</i>. <i>spiralis</i> is enriched at LTR retrotransposons and DNA transposons relative to genome-wide CG DNA methylation levels. Categories shown are as defined by Repeatmasker. ***chi-squared <i>p</i> < 1e−40; *chi-squared <i>p</i> < 1e−5. <i>T</i>. <i>spiralis</i> Repeatmasker annotations are in the supporting information. DNA methylation data for the analysis was taken from [<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002061#pbio.1002061.ref041" target="_blank">41</a>]. (D) Evidence for RNA directed DNA methylation in <i>T</i>. <i>spiralis</i>. The density plot shows small RNA reads for all genes (black) and genes with DNA methylation (red). A shift towards higher levels of small RNA reads is seen for DNA methylated genes. (E) A model for the evolution of transposon silencing pathways. Expression of transposable elements is recognized at the level of RNA through structural or sequence features. Consequently, transposable elements are silenced post-transcriptionally through cleavage (RNA) or transcriptionally through histone modification and/or DNA methylation (DNA). This interplay between the RNA and DNA level through different pathways is shown here. Symbols indicate pathways used for defence against transposons in a species, not conservation of individual protein factors. Note that RdRPs can act upstream or downstream of Dicer. Branch lengths are for illustration only.</p

    RNA dependent RNA polymerase sequence analysis.

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    <p>(A) Unrooted phylogenetic tree of RNA dependent RNA polymerase sequences from curated nematode genomes, <i>Arabidopsis thaliana</i>, and <i>S</i>. <i>pombe</i>. Whilst nematode RNA dependent RNA polymerases are a distinct class, RRF-3 and RRF-1/RRF-2/EGO-1 define separate subgroups and only the RRF-3 subgroup is conserved in <i>T</i>. <i>spiralis</i>. Branch support values from 100 bootstraps are shown in red at each bifurcation. The tree file is in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002061#pbio.1002061.s004" target="_blank">S4 Data</a>. (B) A portion of the multiple sequence alignment of RdRP (Muscle) where a conserved, proline-rich loop is inserted in RRF-1/RRF-2/EGO-1 family polymerases, not present in either RRF-3 family RdRPs or in plant or fungal RdRPs. The full sequence alignment is in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002061#pbio.1002061.s002" target="_blank">S2 Data</a>.</p
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