75 research outputs found

    Tabaq: In a State of Flux

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    Retrospective evaluation of landslide susceptibility maps and review of validation practice

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    Despite the widespread application of landslide susceptibility analyses, there is hardly any information about whether or not the occurrence of recent landslide events was correctly predicted by the relevant susceptibility maps. Hence, the objective of this study is to evaluate four landslide susceptibility maps retrospectively in a landslide-prone area of the Swabian Alb (Germany). The predictive performance of each susceptibility map is evaluated based on a landslide event triggered by heavy rainfalls in the year 2013. The retrospective evaluation revealed significant variations in the predictive accuracy of the analyzed studies. Both completely erroneous as well as very precise predictions were observed. These differences are less attributed to the applied statistical method and more to the quality and comprehensiveness of the used input data. Furthermore, a literature review of 50 peer-reviewed articles showed that most landslide susceptibility analyses achieve very high validation scores. 73% of the analyzed studies achieved an area under curve (AUC) value of at least 80%. These high validation scores, however, do not reflect the high uncertainty in statistical susceptibility analysis. Thus, the quality assessment of landslide susceptibility maps should not only comprise an index-based, quantitative validation, but also an additional qualitative plausibility check considering local geomorphological characteristics and local landslide mechanisms. Finally, the proposed retrospective evaluation approach cannot only help to assess the quality of susceptibility maps and demonstrate the reliability of such statistical methods, but also identify issues that will enable the susceptibility maps to be improved in the future

    Translation of stable hepadnaviral mRNA cleavage fragments induced by the action of phosphorothioate-modified antisense oligodeoxynucleotides

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    Phosphorothioate-modified antisense oligodeoxynucleotides (ASOs) are used to suppress gene expression by inducing RNase H-mediated cleavage with subsequent degradation of the target mRNA. However, previous observations suggest that ASO/RNase H can also result in the generation of stable mRNA cleavage fragments and expression of truncated proteins. Here, we addressed the underlying translational mechanisms in more detail using hepadnavirus-transfected hepatoma cells as a model system of antisense therapy. Generation of stable mRNA cleavage fragments was restricted to the ASO/RNase H pathway and not observed upon cotransfection of isosequential small interfering RNA or RNase H-incompetent oligonucleotides. Furthermore, direct evidence for translation of mRNA fragments was established by polysome analysis. Polysome-associated RNA contained cleavage fragments devoid of a 5′ cap structure indicating that translation was, at least in part, cap-independent. Further analysis of the uncapped cleavage fragments revealed that their 5′ terminus and initiation codon were only separated by a few nucleotides suggesting a 5′ end-dependent mode of translation, whereas internal initiation could be ruled out. However, the efficiency of translation was moderate compared to uncleaved mRNA and amounted to 13–24% depending on the ASO used. These findings provide a rationale for understanding the translation of mRNA fragments generated by ASO/RNase H mechanistically

    Early adaptive immune activation detected in monozygotic twins with prodromal multiple sclerosis

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    Multiple sclerosis (MS) is a disabling disease of the CNS. Inflammatory features of MS include lymphocyte accumulations in the CNS and cerebrospinal fluid (CSF). The preclinical events leading to established MS are still enigmatic. Here we compared gene expression patterns of CSF cells from MS-discordant monozygotic twin pairs. Six "healthy" co-twins, who carry a maximal familial risk for developing MS, showed subclinical neuroinflammation (SCNI) with small MRI lesions. Four of these subjects had oligoclonal bands (OCBs). By single-cell RNA sequencing of 2752 CSF cells, we identified clonally expanded CD8(+) T cells, plasmablasts, and, to a lesser extent, CD4(+) T cells not only from MS patients but also from subjects with SCNI. In contrast to nonexpanded T cells, clonally expanded T cells showed characteristics of activated tissue-resident memory T (T-RM) cells. The T-RM-like phenotype was detectable already in cells from SCNI subjects but more pronounced in cells from patients with definite MS. Expanded plasmablast clones were detected only in MS and SCNI subjects with OCBs. Our data provide evidence for very early concomitant activation of 3 components of the adaptive immune system in MS, with a notable contribution of clonally expanded T-RM-like CD8(+) cells

    The IntAct database:Efficient access to fine-grained molecular interaction data

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    The IntAct molecular interaction database (https://www.ebi.ac.uk/intact) is a curated resource of molecular interactions, derived from the scientific literature and from direct data depositions. As of August 2021, IntAct provides more than one million binary interactions, curated by twelve global partners of the International Molecular Exchange consortium, for which the IntAct database provides a shared curation and dissemination platform. The IMEx curation policy has always emphasised a fine-grained data and curation model, aiming to capture the relevant experimental detail essential for the interpretation of the provided molecular interaction data. Here, we present recent curation focus and progress, as well as a completely redeveloped website which presents IntAct data in a much more user-friendly and detailed way

    The MIntAct project—IntAct as a common curation platform for 11 molecular interaction databases

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    IntAct (freely available at http://www.ebi.ac.uk/intact) is an open-source, open data molecular interaction database populated by data either curated from the literature or from direct data depositions. IntAct has developed a sophisticated web-based curation tool, capable of supporting both IMEx- and MIMIx-level curation. This tool is now utilized by multiple additional curation teams, all of whom annotate data directly into the IntAct database. Members of the IntAct team supply appropriate levels of training, perform quality control on entries and take responsibility for long-term data maintenance. Recently, the MINT and IntAct databases decided to merge their separate efforts to make optimal use of limited developer resources and maximize the curation output. All data manually curated by the MINT curators have been moved into the IntAct database at EMBL-EBI and are merged with the existing IntAct dataset. Both IntAct and MINT are active contributors to the IMEx consortium (http://www.imexconsortium.org

    Les politiques des sciences. Séminaire alternatif

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    Michel Agier, Mathieu Arnoux, Alban Bensa, Alain Blum, Simona Cerutti, Francis Chateauraynaud, Robert Descimon, Nicolas Dodier, Jean-Claude Galey, Nancy L. Green, Christian Jouhaud, Christian Topalov, directeurs d’étudesIsabelle Backouche, Juliette Cadiot, Fanny Cosandey, Sophie Desrosiers, André Gunthert, Liora Israël, Cyril Lemieux, Mary Picone, Sylvain Piron, maîtres de conférencesIrène Bellier, directrice de recherche au CNRSMichel Barthélémy, Elie Haddad, Cédric Lomba, Birgit Müller, Sop..

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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