Earthquake risk communication as dialogue-insights from a workshop in Istanbul's urban renewal neighbourhoods

An important paradox of hazard communication is that the more effectively a potential physical threat is made public by the scientist, the more readily the scientific message becomes normalized into the daily discourses of ordinary life. As a result, a heightened risk awareness does not necessarily motivate personal or collective preparedness. If geoscientists are to help at-risk communities adopt meaningful measures to protect themselves, new strategies are needed for public communication and community engagement. This paper outlines an attempt to develop a novel approach to train geoscientists, using doctoral and post-doctoral researchers in an EU integrated training network studying tectonic processes and geohazards in Turkey. An urban field visit to seismically vulnerable neighbourhoods in Istanbul allowed the researchers to meet with local residents facing the seismic threat. Those meetings exposed the complex social, political and cultural concerns among Istanbul's at-risk urban communities. These concerns were used to provoke subsequent focus group discussions among the group of geoscientists about roles, responsibilities and methods of communicating hazard information to the public. Through the direct testimony of local residents and geoscientists, we explore the form that new strategies for public communication and community engagement might take

Extreme 18O-enrichment in majorite constrains a crustal origin of transition zone diamonds

The fate of subducted oceanic lithosphere and its role in the planet-scale geochemical cycle is a key problem in solid Earth studies. Asthenospheric and transition zone minerals included in diamond have been interpreted as representing subducted oceanic crust based on inclusion REE patterns and strong 13C depletion of their host diamond (δ13C as low as -23 ‰). This view/explanation, however, has been challenged by alternative interpretations that variable carbon isotopic compositions either result from high temperature fractionation involving carbides, or reflect primordial, unhomogenised mantle reservoirs. Here, we present the first oxygen isotope analyses of inclusions in such ultradeep diamonds – majoritic garnets in diamond from Jagersfontein (South Africa). The oxygen isotope compositions provide unambiguous evidence for derivation of the inclusions from subducted crustal materials. The δ18OVSMOW values of the majorites range from +8.6 ‰ to +10.0 ‰, well outside that of ambient mantle (+5.5 ±0.4 ‰) and indicate that the protoliths were very heavily weathered at relatively low temperatures. When this information is combined with the broadly eclogitic composition of the majoritic garnets, a derivation from subducted sea-floor basalts is implied. Based on the association between the heavy oxygen and light carbon, the light carbon isotope composition cannot relate to deep mantle processes and is also ultimately derived from the crust

Communicating Seismic Risk: the Geoethical Challenges of a People-Centred, Participatory Approach

International audienceThe Sendai Framework for Disaster Risk Reduction (SFDRR) encourages scientists to participate in bottom-up risk communication approaches that directly engage hazard-prone populations. Effective communication of seismic risks not only has economic impacts in terms of hazard mitigation but also provides social value in potentially empowering the marginalized populations that disproportionately live in high-risk areas. This emphasis on community-focused disaster preparedness, however, presents a novel set of communication challenges for geoscientists. Few scientists have training in or experience of translating their science for lay publics, and conveying complex risk information is especially difficult in circumstances where scientific issues are socially contested and politically charged. Recognising that disaster threats can create troublesome information battlegrounds, this paper explores the ethical and practical aspects of seismic risk communication, motivated by an early-career earth scientists' workshop in Istanbul that voiced the concerns of young geoscientists confronted firsthand by at-risk publics. Those concerns form the basis of a wider review of the risk communication issues that are likely to be encountered if community-centred participatory DRR approaches are to be adopted by earthquake science researchers

Phylogenomic assessment prompts recognition of the Serianthes clade and confirms the monophyly of Serianthes and its relationship with Falcataria and Wallaceodendron in the wider ingoid clade (Leguminosae, Caesalpinioideae)

The Indo-Pacific legume genus Serianthes was recently placed in the Archidendron clade (sensu Koenen et al. 2020), a subclade of the mimosoid clade in subfamily Caesalpinioideae, which also includes Acacia, Archidendron, Archidendropsis, Falcataria, Pararchidendron, Paraserianthes and Wallaceodendron. Serianthes comprises ca. 18 species, five subspecies and two varieties that are characterised by bipinnately compound leaves with alternate sessile leaflets, branched axillary corymbiform panicles and woody indehiscent pods. Generic relationships, as well as species relationships within genera in the Archidendron clade, remain uncertain. While the sister relationship between Serianthes and the genus Falcataria is strongly supported by molecular data, the distinction between Serianthes and the monotypic genus Wallaceodendron has been questioned, based on their similar flower and fruit morphologies. We combined three gene-enriched hybrid capture DNA sequence datasets (generated from the 964 mimobaits v1 probe set, the expanded 997 mimobaits v2 probe set and the GoFlag angiosperm 408 probe set) and used their overlapping markers (77 loci of the target exonic and flanking regions) to test the monophyly of Serianthes and to investigate generic relationships within the Archidendron clade using 55 ingoid plus two outgroup taxa. We show that Serianthes is monophyletic, confirm the Serianthes + Falcataria sister relationship to Wallaceodendron and recognise this combined clade as the Serianthes clade within the Archidendron clade. We also evaluated the use of overlapping loci across datasets in combination with concordance analyses to test generic relationships and further investigate previously unresolved relationships across the wider ingoid clade. Concordance analysis revealed limited gene tree conflicts near the tips of the Archidendron clade, but increased discordance at the base of the clade, which could be attributed to rapid lineage divergence (radiation) and/or incomplete lineage sorting

Comparison of the fragmentation behavior of DNA and LNA single strands and duplexes

DNA and locked nucleic acid (LNA) were characterized as single strands, as well as double stranded DNA‐DNA duplexes and DNA‐LNA hybrids using tandem mass spectrometry with collision‐induced dissociation. Additionally, ion mobility spectrometry was carried out on selected species. Oligonucleotide duplexes of different sequences – bearing mismatch positions and abasic sites of complementary DNA 15‐mers – were investigated to unravel general trends in their stability in the gas phase. Single stranded LNA oligonucleotides were also investigated with respect to their gas phase behavior and fragmentation upon collision‐induced dissociation. In contrast to the collision‐induced dissociation of DNA, almost no base loss was observed for LNAs. Here, backbone cleavages were the dominant dissociation pathways. This finding was further underlined by the need for higher activation energies. Base losses from the LNA strand were also absent in fragmentation experiments of the investigated DNA‐LNA hybrid duplexes. While DNA‐DNA duplexes dissociated easily into single stranded fragments, the high stability of DNA‐LNA hybrids resulted in predominant fragmentation of the DNA part rather than the LNA, while base losses were only observed from the DNA single strand of the hybrid

Non-native vascular flora of the Arctic : Taxonomic richness, distribution and pathways

We present a comprehensive list of non-native vascular plants known from the Arctic, explore their geographic distribution, analyze the extent of naturalization and invasion among 23 subregions of the Arctic, and examine pathways of introductions. The presence of 341 non-native taxa in the Arctic was confirmed, of which 188 are naturalized in at least one of the 23 regions. A small number of taxa (11) are considered invasive; these plants are known from just three regions. In several Arctic regions there are no naturalized non-native taxa recorded and the majority of Arctic regions have a low number of naturalized taxa. Analyses of the non-native vascular plant flora identified two main biogeographic clusters within the Arctic: American and Asiatic. Among all pathways, seed contamination and transport by vehicles have contributed the most to non-native plant introduction in the Arctic.Peer reviewe

Production of 40Ar by an overlooked mode of 40K decay with implications for K-Ar geochronology

The decay of 40K to the stable isotopes 40Ca and 40Ar is used as a measure of time for both the K-Ca and KAr geochronometers, the latter of which is most generally utilized by the variant 40Ar/ 39Ar system. The increasing precision of geochronology has forced practitioners to deal with the systematic uncertainties rooted in all radioisotope dating methods. A major component of these systematic uncertainties for the K-Ar and 40Ar/ 39Ar techniques is imprecisely determined decay constants and an incomplete knowledge of the decay scheme of 40K. Recent geochronology studies question whether 40K can decay to 40Ar via an electron capture directly to ground state (ECground), citing the lack of experimental verification as reasoning for its omission. In this study, we (1) provide a theoretical argument in favor of the presence of this decay mode and (2) evaluate the magnitude of this decay mode by calculating the electron capture to positron ratio (ECground/β+) and comparing calculated ratios to previously published calculations, which yield ECground/β+ between 150–212. We provide support for this calculation through comparison of the experimentally verified ECground/β+ ratio of 22Na with our calculation using the theory of β decay. When combined with measured values of β + and β − decay rates, the best estimate for the calculated ECground/β+ for 40K yields a partial decay constant for 40K direct to ground-state 40Ar of 11.6±1.5×10−13 a −1 (2σ). We calculate a partial decay constant of 40K to 40Ar of 0.592 ± 0.014 × 10−10 a −1 and a total decay constant of 5.475 ± 0.107 × 10−10 a −1 (2σ), and we conclude that although omission of this decay mode can be significant for K-Ar dating, it is minor for 40Ar/ 39Ar geochronology and is therefore unlikely to have significantly biased published measurements

Evidence for ground-state electron capture of 40^{40}K

Potassium-40 is a widespread isotope whose radioactivity impacts estimated geological ages spanning billions of years, nuclear structure theory, and subatomic rare-event searches - including those for dark matter and neutrinoless double-beta decay. The decays of this long-lived isotope must be precisely known for its use as a geochronometer, and to account for its presence in low-background experiments. There are several known decay modes for $^{40}$K, but a predicted electron-capture decay directly to the ground state of argon-40 has never been observed, while theoretical predictions span an order of magnitude. The KDK Collaboration reports on the first observation of this rare decay, obtained using a novel combination of a low-threshold X-ray detector surrounded by a tonne-scale, high-efficiency $\gamma$-ray tagger at Oak Ridge National Laboratory. A blinded analysis reveals a distinctly nonzero ratio of intensities of ground-state electron-captures ($I_{\text{EC}^0}$) over excited-state ones ($I_{\text{EC}^*}$) of $I_{\text{EC}^0} / I_{\text{EC}^*}=0.0095\stackrel{\text{stat}}{\pm}0.0022\stackrel{\text{sys}}{\pm}0.0010$ (68% CL), with the null hypothesis rejected at 4$\sigma$ [Stukel et al., DOI:10.1103/PhysRevLett.131.052503]. This unambiguous signal yields a branching ratio of $I_{\text{EC}^0}=0.098\%\stackrel{\text{stat}}{\pm}0.023\%\stackrel{\text{sys}}{\pm}0.010$, roughly half of the commonly used prediction. This first observation of a third-forbidden unique electron capture improves understanding of low-energy backgrounds in dark-matter searches and has implications for nuclear-structure calculations. A shell-model based theoretical estimate for the $0\nu\beta\beta$ decay half-life of calcium-48 is increased by a factor of $7^{+3}_{-2}$. Our nonzero measurement shifts geochronological ages by up to a percent; implications are illustrated for Earth and solar system chronologies.Comment: This is a companion submission to Stukel et al (KDK collaboration) "Rare $^{40}$K decay with implications for fundamental physics and geochronology" [arXiv:2211.10319; DOI: 10.1103/PhysRevLett.131.052503]. As such, both texts share some figures and portions of text. This version updates the text following its review and production proces

A genome for gnetophytes and early evolution of seed plants

Genome sequencing, assembly and annotation were conducted by the Novogene Bioinformatics Institute, Beijing, China; mutual contracts were No. NHT140016 and NVT140016004. This work was supported by funding from the Scientific Project of Shenzhen Urban Administration (201519) and a Major Technical Research Project of the Innovation of Science and Technology Commission of Shenzhen (JSGG20140515164852417). Additional funding was provided in particular by the Scientific Research Program of Sino-Africa Joint Research Center (SAJL201607). We thank X.Q. Wang, G.W. Hu, Z.D. Chen and Y.H. Guo for comments on gnetophyte phylogenetic relationships and ecological issues; H. Wu and X.P. Ning for discussion of related organ development; K.K. Wan and S. Sun for additional help on the analysis of repeats. We also thank X.Y. for support of funding coordination. Y.V.d.P. acknowledges the Multidisciplinary Research Partnership ‘Bioinformatics: from nucleotides to networks’ Project (no. 01MR0310W) of Ghent University, and funding from the European Union Seventh Framework Programme (FP7/2007-2013) under European Research Council Advanced Grant Agreement 322739-DOUBLEUP