32 research outputs found

    COVID-19 and gendered governance: countries led by women did not employ more stringent strategies than those led by men – but they did act faster

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    Mette Marie Staehr Harder and Christoffer Bugge Harder examine whether countries led by women applied more extensive measures to combat COVID-19 than those led by men. While they find no indications that the former applied more extensive health responses over time, OECD countries led by women did enact their respective maximum shutdown measures significantly more quickly than those led by men

    Local diversity of heathland Cercozoa explored by in-depth sequencing

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    Cercozoa are abundant free-living soil protozoa and quantitatively important in soil food webs; yet, targeted high-throughput sequencing (HTS) has not yet been applied to this group. Here we describe the development of a targeted assay to explore Cercozoa using HTS, and we apply this assay to measure Cercozoan community response to drought in a Danish climate manipulation experiment (two sites exposed to artificial drought, two unexposed). Based on a comparison of the hypervariable regions of the 18S ribosomal DNA of 193 named Cercozoa, we concluded that the V4 region is the most suitable for group-specific diversity analysis. We then designed a set of highly specific primers (encompassing ~270 bp) for 454 sequencing. The primers captured all major cercozoan groups; and >95% of the obtained sequences were from Cercozoa. From 443 350 high-quality short reads (>300 bp), we recovered 1585 operational taxonomic units defined by >95% V4 sequence similarity. Taxonomic annotation by phylogeny enabled us to assign >95% of our reads to order level and ~85% to genus level despite the presence of a large, hitherto unknown diversity. Over 40% of the annotated sequences were assigned to Glissomonad genera, whereas the most common individually named genus was the euglyphid Trinema. Cercozoan diversity was largely resilient to drought, although we observed a community composition shift towards fewer testate amoebae

    Towards diagnostic metagenomics of Campylobacter in fecal samples

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    Abstract Background The development of diagnostic metagenomics is driven by the need for universal, culture-independent methods for detection and characterization of pathogens to substitute the time-consuming, organism-specific, and often culture-based laboratory procedures for epidemiological source-tracing. Some of the challenges in diagnostic metagenomics are, that it requires a great next-generation sequencing depth and unautomated data analysis. Results DNA from human fecal samples spiked with 7.75 × 101−7.75 × 107 colony forming unit (CFU)/ml Campylobacter jejuni and chicken fecal samples spiked with 1 × 102–1 × 106 CFU/g Campylobacter jejuni was sequenced and data analysis was done by the metagenomic tools Kraken and CLARK. More hits were obtained at higher spiking levels, however with no significant linear correlations (human samples p = 0.12, chicken samples p = 0.10). Therefore, no definite detection limit could be determined, but the lowest spiking levels found positive were 7.75 × 104 CFU/ml in human feces and 103 CFU/g in chicken feces. Eight human clinical fecal samples with estimated Campylobacter infection loads from 9.2 × 104–1.0 × 109 CFU/ml were analyzed using the same methods. It was possible to detect Campylobacter in all the clinical samples. Conclusions Sensitivity in diagnostic metagenomics is improving and has reached a clinically relevant level. There are still challenges to overcome before real-time diagnostic metagenomics can replace quantitative polymerase chain reaction (qPCR) or culture-based surveillance and diagnostics, but it is a promising new technology

    In vitro evidence of root colonization suggests ecological versatility in the genus Mycena

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    Acknowledgements: The European commission is acknowledged for a MSCA grant to C.B.H (grant no. 658849), the University of Oslo for further funding of the project, and the Swedish University of Agricultural Sciences for hosting parts of the experiments. C.B.H was funded by an internationalisation grant from the Carlsberg Research Grant Foundation at the time of writing (grant no. CF18-0809). We would like to thank Jerome Guerrand for aid in in vitro laboratory techniques, the Norwegian Forest Seed Center for provision of seeds, Hedda Weitz and Tatiana A. Semenova-Nelson and Taina Pennanen for provision of fungal cultures. We would like to thank Marc-AndrĂŠ Selosse, Peter Kennedy and four anonymous referees for valuable comments to an earlier version of this manuscript.Peer reviewedPublisher PD

    Mycena species can be opportunist-generalist plant root invaders

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    ACKNOWLEDGEMENTS We thank Karl-Henrik Larsson and Arne Aronsen for provisions of specimens from the Natural History Museum of Oslo and help with the identification of field specimens from Svalbard. We further thank Cecilie Mathiesen and Mikayla Jacobs for technical assistance in the laboratory, Brendan J. Furneaux for valuable input to the R script, and the curators of H, TUR, and OULU. The Mycena ITS sequences originating from the specimens deposited in H, TUR, and OULU were produced as part of the Finnish Barcode of Life Project (FinBOL) funded by the Ministry of Environment, Finland (YM23/5512/2013), Otto A Malm's Donationsfond, and the Kone Foundation. We thank the European Commission (grant no. 658849) and the Carlsberg Foundation (grant no. CF18-0809) for grants to C.B. Harder that made this research possible. C.B. Harder was financed by a grant from the Danish Independent Research Fund DFF/FNU 2032-00064B (SapMyc) at the time of writing. Research Funding Carlsbergfondet. Grant Number: CF18-0809 Danish Independent Research Fund. Grant Number: 2032-00064B European Commission. Grant Number: 658849 Ministry of Environment, Finland. Grant Number: YM23/5512/2013Peer reviewedPublisher PD

    Pyrosequencing and genetic diversity of microeukaryotes

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    Data for platform, bases and reads for sequencing efforts.

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    Data for platform, bases and reads for sequencing efforts.</p

    Ultrastructure and Phylogenetic Position of <i>Regin rotiferus</i> and <i>Otto terricolus</i> Genera et Species Novae (Bicosoecida, Heterokonta/Stramenopiles)

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    We describe two novel flagellates isolated from soil, Regin rotiferus and Otto terricolus, genera et species novae, which we cultivated and characterized by light and transmission electron microscopy and by 18S rDNA sequence analysis. Both strains exhibit the key characteristic structural feature of Bicosoecida; i.e. the L-shaped cytostomal root system with an x-fiber, used for feeding. Otto terricolus displays unique novel morphological traits; thus, it has a basal swelling on each flagellum, a root 3/root 2 distribution of 10 + 1 microtubules, and an amoeboid stage in its life cycle. Regin rotiferus has flagella without swellings and a root 3/root 2 distribution of 7 + 3 microtubules, a pattern commonly observed in the Bicosoecida. We present an updated exhaustive maximum likelihood phylogeny of 48 cultured, complete or nearly complete (+1600 bp) 18S rDNA Bicosoecida sequences. Both new species fall into a well-supported freshwater Siluaniidae clade, without being particularly closely related. The morphology and phylogeny do not conclusively support Rictus as a member of Bicosoecida

    A three-gene phylogeny of the <em>Mycena pura complex</em> reveals 11 phylogenetic species and shows ITS to be unreliable for species identification

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    Phylogenetic analyses of Mycena sect. Calodontes using ITS previously suggested ten cryptic monophyletic ITS lineages within the Mycena pura morphospecies. Here, we compare ITS data (645 bp incl. gaps) from 46 different fruit bodies that represent the previously described ITS diversity with partial tEF-1-Îą (423 bp) and RNA polymerase II (RPB1) (492 bp) sequence data to test the genealogical concordance. While neither of the markers were in complete topological agreement, the branches differing between the tEF and RPB1 trees had a low bootstrap (<50) support, and the partition homogeneity incongruence length difference (ILD) tests were not significant. ILD tests revealed significant discordances between ITS and the tEF and RPB1 markers in several lineages. And our analyses suggested recombination between ITS1 and ITS2, most pronounced in one phylospecies that was identical in tEF and RPB1. Based on the agreement between tEF and RPB1, we defined 11 mutually concordant terminal clades as phylospecies inside the M. pura morphospecies; most of them cryptic. While neither of the markers showed an unequivocal barcoding gap between inter- and intraspecific diversity, the overlap was most pronounced for ITS (intraspecific diversity 0-3.5 %, interspecific diversity 0.4 %-8.8 %). A clustering analysis on tEF separated at a 1.5 % level returned all phylogenetic species as Operational Taxonomic Units (OTUs), while ITS at both a 1.5 % level and at a 3 % threshold level not only underestimated diversity as found by the tEF and RPB1, but also identified an OTU which was not a phylogenetic species. Thus, our investigation does not support the universal suitability of ITS for species recognition in particular, and emphasises the general limitation of single gene analyses combined with single percentage separation values

    <i>Aminobacter</i> MSH1-Mineralisation of BAM in Sand-Filters Depends on Biological Diversity

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    <div><p>BAM (2,6-dichlorobenzamide) is a metabolite of the pesticide dichlobenil. Naturally occurring bacteria that can utilize BAM are rare. Often the compound cannot be degraded before it reaches the groundwater and therefore it poses a serious threat to drinking water supplies. The bacterial strain <i>Aminobacter</i> MSH1 is a BAM degrader and therefore a potential candidate to be amended to sand filters in waterworks to remediate BAM polluted drinking water. A common problem in bioremediation is that bacteria artificially introduced into new diverse environments often thrive poorly, which is even more unfortunate because biologically diverse environments may ensure a more complete decomposition. To test the bioaugmentative potential of MSH1, we used a serial dilution approach to construct microcosms with different biological diversity. Subsequently, we amended <i>Aminobacter</i> MSH1 to the microcosms in two final concentrations; i.e. 10<sup>5</sup> cells mL<sup>-1</sup> and 10<sup>7</sup> cells mL<sup>-1</sup>. We anticipated that BAM degradation would be most efficient at “intermediate diversities” as low diversity would counteract decomposition because of incomplete decomposition of metabolites and high diversity would be detrimental because of eradication of <i>Aminobacter</i> MSH1. This hypothesis was only confirmed when <i>Aminobacter</i> MSH1 was amended in concentrations of 10<sup>5</sup> cells mL<sup>-1</sup>.Our findings suggest that <i>Aminobacter</i> MSH1 is a very promising bioremediator at several diversity levels.</p></div
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