36 research outputs found

    Sustained IFN signaling is associated with delayed development of SARS-CoV-2-specific immunity.

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    Plasma RNAemia, delayed antibody responses and inflammation predict COVID-19 outcomes, but the mechanisms underlying these immunovirological patterns are poorly understood. We profile 782 longitudinal plasma samples from 318 hospitalized patients with COVID-19. Integrated analysis using k-means reveals four patient clusters in a discovery cohort: mechanically ventilated critically-ill cases are subdivided into good prognosis and high-fatality clusters (reproduced in a validation cohort), while non-critical survivors segregate into high and low early antibody responders. Only the high-fatality cluster is enriched for transcriptomic signatures associated with COVID-19 severity, and each cluster has distinct RBD-specific antibody elicitation kinetics. Both critical and non-critical clusters with delayed antibody responses exhibit sustained IFN signatures, which negatively correlate with contemporaneous RBD-specific IgG levels and absolute SARS-CoV-2-specific B and CD4 <sup>+</sup> T cell frequencies. These data suggest that the "Interferon paradox" previously described in murine LCMV models is operative in COVID-19, with excessive IFN signaling delaying development of adaptive virus-specific immunity

    Assessing the accuracy of forest cover map for 1990, 2000 and 2010 at national scale in Gabon

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    The Gabonese Agency for Space Studies and Observations (AGEOS) was set up in 2010 with one of its aims being to develop a national forest monitoring capability. In addition, the European Space Agency (ESA) has developed its activities in the Congo basin through the REDD extension of its GMES Service Element on Forest Monitoring program (GSE\FM). The ESA GSE\FM REDD extension project is seen by the Gabonese authorities as a precursor to the establishment of the AGEOS for the monitoring of forest cover. During this phase of the project, the production of forest area maps and forest cover change maps for 1990 and 2000 was initiated with a wall to wall approach for the total area of Gabon and about a third of the country for 2010. Initial results confirm the generally low level of deforestation expected in the Congo basin region and in Gabon in particular. However, these results cannot be used without a thorough and statistically sound assessment of thematic accuracy. Thus, a suitable sampling approach was developed to assess the accuracy and results show that these products exceed the requirements set by AGEOS with an overall accuracy above 95%

    Using next-generation sequencing for molecular reconstruction of past arctic vegetation and climate

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    Palaeoenvironments and former climates are typically inferred from pollen and macrofossil records. This approach is time-consuming and suffers from low taxonomic resolution and biased taxon sampling. Here, we test an alternative DNA-based approach utilizing the P6 loop in the chloroplast trnL (UAA) intron; a short (13–158 bp) and variable region with highly conserved flanking sequences. For taxonomic reference, a whole trnL intron sequence database was constructed from recently collected material of 842 species, representing all widespread and/or ecologically important taxa of the species-poor arctic flora. The P6 loop alone allowed identification of all families, most genera (&gt;75%) and one-third of the species, thus providing much higher taxonomic resolution than pollen records. The suitability of the P6 loop for analysis of samples containing degraded ancient DNA from a mixture of species is demonstrated by high-throughput parallel pyrosequencing of permafrost-preserved DNA and reconstruction of two plant communities from the last glacial period. Our approach opens new possibilities for DNA-based assessment of ancient as well as modern biodiversity of many groups of organisms using environmental samples.<br/

    Venous malformation: update on aetiopathogenesis, diagnosis and management

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    The aim of this review was to discuss the current knowledge on aetiopathogenesis, diagnosis and therapeutic management of venous malformations (VMs). VMs are slow-flow vascular anomalies. They are simple, sporadic or familial (cutaneomucosal VMs or glomuvenous malformations), combined (e.g. capillaro-venous and capillaro-lymphaticovenous malformations) or syndromic (Klippel-Trenaunay, blue rubber bleb naevus and Maffucci). Genetic studies have identified causes of familial forms and of 40% of sporadic VMs. Another diagnostic advancement is the identification of elevated D-dimer level as the first biomarker of VMs within vascular anomalies. Those associated with pain are often responsive to low-molecular-weight heparin, which should also be used to avoid disseminated intravascular coagulopathy secondary to intervention, especially if fibrinogen level is low. Finally, development of a modified sclerosing agent, ethylcellulose-ethanol, has improved therapy. It is efficient and safe, and widens indications for sclerotherapy to sensitive and dangerous areas such as hands, feet and periocular area

    Floral structure in Licuala peltata (Arecaceae: Coryphoideae) with special reference to the architecture of the unusual labyrinthine nectary

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    The structure and late development of the flowers of the South-East Asian bee-pollinated palm Licuala peltata are described with special focus on the architecture of the unusual labyrinthine nectaries. The nectaries are derived from septal nectaries by extensive convolution of the carpel flank surfaces below the ovary throughout the inner floral base, thus also encompassing the inner surface of the corolla–androecium tube. A comparison with septal nectaries elsewhere in Arecaceae and with labyrinthine nectaries in other monocots shows that labyrinthine nectaries situated below the ovary, as described here, are not known from any other palms, but are similar to those of a few Bromeliaceae and, less strongly convoluted, some Haemodoraceae and Xanthorrhoeaceae. In addition, the substantial participation of parts other than the gynoecium in the nectary architecture of Licuala appears unique at the level of monocots
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