| 1. |
- Abel, I, et al.
(author)
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Overview of the JET results with the ITER-like wall
- 2013
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 53:10, s. 104002-
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Journal article (peer-reviewed)abstract
- Following the completion in May 2011 of the shutdown for the installation of the beryllium wall and the tungsten divertor, the first set of JET campaigns have addressed the investigation of the retention properties and the development of operational scenarios with the new plasma-facing materials. The large reduction in the carbon content (more than a factor ten) led to a much lower Z(eff) (1.2-1.4) during L- and H-mode plasmas, and radiation during the burn-through phase of the plasma initiation with the consequence that breakdown failures are almost absent. Gas balance experiments have shown that the fuel retention rate with the new wall is substantially reduced with respect to the C wall. The re-establishment of the baseline H-mode and hybrid scenarios compatible with the new wall has required an optimization of the control of metallic impurity sources and heat loads. Stable type-I ELMy H-mode regimes with H-98,H-y2 close to 1 and beta(N) similar to 1.6 have been achieved using gas injection. ELM frequency is a key factor for the control of the metallic impurity accumulation. Pedestal temperatures tend to be lower with the new wall, leading to reduced confinement, but nitrogen seeding restores high pedestal temperatures and confinement. Compared with the carbon wall, major disruptions with the new wall show a lower radiated power and a slower current quench. The higher heat loads on Be wall plasma-facing components due to lower radiation made the routine use of massive gas injection for disruption mitigation essential.
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| 2. |
- Bache, Iben, et al.
(author)
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An excess of chromosome 1 breakpoints in male infertility.
- 2004
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In: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813. ; 12:12, s. 993-1000
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Journal article (peer-reviewed)abstract
- In a search for potential infertility loci, which might be revealed by clustering of chromosomal breakpoints, we compiled 464 infertile males with a balanced rearrangement from Mendelian Cytogenetics Network database (MCNdb) and compared their karyotypes with those of a Danish nation-wide cohort. We excluded Robertsonian translocations, rearrangements involving sex chromosomes and common variants. We identified 10 autosomal bands, five of which were on chromosome 1, with a large excess of breakpoints in the infertility group. Some of these could potentially harbour a male-specific infertility locus. However, a general excess of breakpoints almost everywhere on chromosome 1 was observed among the infertile males: 26.5 versus 14.5% in the cohort. This excess was observed both for translocation and inversion carriers, especially pericentric inversions, both for published and unpublished cases, and was significantly associated with azoospermia. The largest number of breakpoints was reported in 1q21; FISH mapping of four of these breakpoints revealed that they did not involve the same region at the molecular level. We suggest that chromosome 1 harbours a critical domain whose integrity is essential for male fertility.
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| 3. |
- Bengtson, Stefan, et al.
(author)
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Eocene animal trace fossils in 1.7-billion-year-old metaquartzites
- 2021
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In: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences of the United States. - 0027-8424 .- 1091-6490. ; 118:40, s. 1-8
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Journal article (peer-reviewed)abstract
- The Paleoproterozoic (1.7 Ga [billion years ago]) metasedimentary rocks of the Mount Barren Group in southwestern Australia contain burrows indistinguishable from ichnogenera Thalassinoides, Ophiomorpha, Teichichnus, and Taenidium, known from firmgrounds and softgrounds. The metamorphic fabric in the host rock is largely retained, and because the most resilient rocks in the sequence, the metaquartzites, are too hard for animal burrowing, the trace fossils have been interpreted as predating the last metamorphic event in the region. Since this event is dated at 1.2 Ga, this would bestow advanced animals an anomalously early age. We have studied the field relationships, petrographic fabric, and geochronology of the rocks and demonstrate that the burrowing took place during an Eocene transgression over a weathered regolith. At this time, the metaquartzites of the inundated surface had been weathered to friable sandstones or loose sands (arenized), allowing for animal burrowing. Subsequent to this event, there was a resilicification of the quartzites, filling the pore space with syntaxial quartz cement forming silcretes. Where the sand grains had not been dislocated during weathering, the metamorphic fabric was seemingly restored, and the rocks again assumed the appearance of hard metaquartzites impenetrable to animal burrowing.
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| 4. |
- Bengtson, Stefan, 1947-, et al.
(author)
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Fungus-like mycelial fossils in 2.4-billion-year-old vesicular basalt.
- 2017
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In: Nature Ecology & Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 1:6, s. 1-6
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Journal article (peer-reviewed)abstract
- Fungi have recently been found to comprise a significant part of the deep biosphere in oceanic sediments and crustal rocks. Fossils occupying fractures and pores in Phanerozoic volcanics indicate that this habitat is at least 400 million years old, but its origin may be considerably older. A 2.4-billion-year-old basalt from the Palaeoproterozoic Ongeluk Formation in South Africa contains filamentous fossils in vesicles and fractures. The filaments form mycelium-like structures growing from a basal film attached to the internal rock surfaces. Filaments branch and anastomose, touch and entangle each other. They are indistinguishable from mycelial fossils found in similar deep-biosphere habitats in the Phanerozoic, where they are attributed to fungi on the basis of chemical and morphological similarities to living fungi. The Ongeluk fossils, however, are two to three times older than current age estimates of the fungal clade. Unless they represent an unknown branch of fungus-like organisms, the fossils imply that the fungal clade is considerably older than previously thought, and that fungal origin and early evolution may lie in the oceanic deep biosphere rather than on land. The Ongeluk discovery suggests that life has inhabited submarine volcanics for more than 2.4 billion years.
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| 5. |
- Ivarsson, Magnus, et al.
(author)
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A Cryptic Alternative for the Evolution of Hyphae
- 2020
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In: Bioessays. - : John Wiley & Sons. - 0265-9247 .- 1521-1878. ; 42:6, s. 1-9
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Journal article (peer-reviewed)abstract
- A growing awareness of a subsurface fossil record of mostly hyphal fungi organisms stretching back through the Phanerozoic to approximate to 400 megaannum (Ma) and possibly earlier, provides an alternative view on hyphal development. Parallel with the emergence of hyphal fungi during Ordovician-Devonian times when plants colonized the land, which is the traditional notion of hyphal evolution, hyphae-based fungi existed in the deep biosphere. New insights suggest that the fundamental functions of hyphae may have evolved in response to an ancient subsurface endolithic life style and might have been in place before the colonization of land. To address the gaps in the current understanding of hyphal evolution a strategy based on research prospects involving investigations of uncharted geological material, new diagnostics, and comparisons to live species is proposed.
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| 6. |
- Ivarsson, Magnus, et al.
(author)
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The fossil record of igneous rock
- 2020
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In: Earth-Science Reviews. - : Elsevier. - 0012-8252 .- 1872-6828. ; 210, s. 1-20
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Journal article (peer-reviewed)abstract
- A growing awareness of life in deep igneous crust expands our appreciation for life's distribution in the upper geosphere through time and space, and extends the known inhabitable realm of Earth and possibly beyond. For most of life's history, until plants colonized land in the Ordovician, the deep biosphere was the largest reservoir of living biomass. This suggests that deep crustal habitats played an important role in the evolution and development of the biosphere. Paradoxically, the paleo-perspective of deep life has been largely neglected in the exploration of the deep biosphere as well as in paleontology as a whole. Here, we review the collective understanding of the fossil record in igneous crust with the aim to highlight a rising research field with great potential for substantial findings and progress in the near future. We include new results that emphasize the importance of direct or indirect dating of fossils and introduction of new techniques into the field. Currently, an incoherent record of morphological fossils- and chemofossils stretching from present to ~2.4 Ga implies the presence of an abundant and rich, yet largely unexplored, fossil record. Further investigations of deep paleo-environments will most certainly result in substantial insights into the distribution and development of biospheres throughout life's history, the early evolution of prokaryotes and eukaryotes, and Earth's early biogeochemical cycles. We emphasize the fossil record of igneous rock to give it the same status as the fossil record in sedimentary rocks, and to implement fossil investigations as standard procedures in future international drilling campaigns.
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| 7. |
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| 8. |
- Senneby, Erik, et al.
(author)
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Bacteremia with Aerococcus sanguinicola: Case Series with Characterization of Virulence Properties.
- 2014
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In: Open Forum Infectious Diseases. - : Oxford University Press (OUP). - 2328-8957. ; 1:1, s. 025-025
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Journal article (peer-reviewed)abstract
- Since Aerococcus sanguinicola was designated as a species in 2001, only a few cases of bacteremia have been reported. The aim with this study was to describe the clinical presentation of A sanguinicola bacteremia and to determine the antibiotic susceptibility and the capacity of the bacteria to form biofilm and to induce platelet aggregation.
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| 9. |
- Stark, J. Camilla, et al.
(author)
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First evidence of Archean mafic dykes at 2.62 Ga in the Yilgarn Craton, Western Australia : Links to cratonisation and the Zimbabwe Craton
- 2018
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In: Precambrian Research. - : Elsevier BV. - 0301-9268. ; 317, s. 1-13
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Journal article (peer-reviewed)abstract
- The Archean Yilgarn Craton in Western Australia hosts at least five generations of Proterozoic mafic dykes, the oldest previously identified dykes belonging to the ca. 2408–2401 Ma Widgiemooltha Supersuite. We report here the first known Archean mafic dyke dated at 2615 ± 6 Ma by the ID-TIMS U-Pb method on baddeleyite and at 2610 ± 25 Ma using in situ SHRIMP U-Pb dating of baddeleyite. Aeromagnetic data suggest that the dyke is part of a series of NE-trending intrusions that potentially extend hundreds of kilometres in the southwestern part of the craton, here named the Yandinilling dyke swarm. Mafic magmatism at 2615 Ma was possibly related to delamination of the lower crust during the final stages of assembly and cratonisation, and was coeval with the formation of late-stage gold deposit at Boddington. Paleogeographic reconstructions suggest that the Yilgarn and Zimbabwe cratons may have been neighbours from ca. 2690 Ma to 2401 Ma and if the Zimbabwe and Kaapvaal cratons amalgamated at 2660–2610 Ma, the 2615 Ma mafic magmatism in the southwestern Yilgarn Craton may be associated with the same tectonic event that produced the ca. 2607–2604 Ma Stockford dykes in the Central Zone of the Limpopo Belt. Paleomagnetic evidence and a similar tectonothermal evolution, including coeval low-pressure high-temperature metamorphism, voluminous magmatism, and emplacement of mafic dykes, support a configuration where the northern part of the Zimbabwe Craton was adjacent to the western margin of the Yilgarn Craton during the Neoarchean. Worldwide, reliably dated mafic dykes of this age have so far been reported from the Yilgarn Craton, the Limpopo Belt and the São Francisco Craton.
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