| 1. |
- Falster, Daniel, et al.
(författare)
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AusTraits, a curated plant trait database for the Australian flora
- 2021
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Ingår i: Scientific Data. - : Nature Portfolio. - 2052-4463. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.
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| 2. |
- Ademuyiwa, Adesoji O., et al.
(författare)
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Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
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| 3. |
- Ahmed, Mohammed, 1986-, et al.
(författare)
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Metabarcoding of soil nematodes: the importance of taxonomiccoverage and availability of reference sequences in choosingsuitable marker(s)
- 2019
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Ingår i: Metabarcoding and Metagenomics. - : Pensoft Publishers. - 2534-9708. ; 3, s. 77-99
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Tidskriftsartikel (refereegranskat)abstract
- For many organisms, there is agreement on the specific genomic region used for developing barcode markers. With nematodes, however, it has been found that the COI region designated for most animals lacks the taxonomic coverage (ability to amplify a diverse group of taxa) required of a metabarcoding marker. For that reason, studies on metabarcoding of nematodes thus far have utilized primarily regions within the highly conserved 18S ribosomal DNA. Two popular markers within this region are the ones flanked by the primer pairs NF1-18Sr2b and SSUF04-SSUR22. The NF1-18Sr2b primer pair, especially, has been critiqued as not being specific enough for nematodes leading to suggestions for other candidate markers while the SSUF04-SSUR22 region has hardly been tested on soil nematodes. The current study aimed to evaluate these two markers against other alternative ones within the 28S rDNA and the COI region for their suitability for nematode metabarcoding. The results showed that the NF1-18Sr2b marker could offer wide coverage and good resolution for characterizing soil nematodes. Sufficient availability of reference sequences for this region was found to be a significant factor that resulted in this marker outperforming the other markers, particularly the 18S-based SSUFO4-SSUR22 marker. None of the other tested regions compared with this marker in terms of the proportion of the taxa recovered. The COI-based marker had the lowest number of taxa recovered, and this was due to the poor performance of its primers and the insufficient number of reference sequences in public databases. In summary, this study highlights how dependent the success of metabarcoding is on the availability of a good reference sequence collection for the marker of choice as well as its taxonomic coverage.
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| 4. |
- Aybas, Deniz, et al.
(författare)
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Search for Axionlike Dark Matter Using Solid-State Nuclear Magnetic Resonance
- 2021
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Ingår i: Physical Review Letters. - : American Physical Society (APS). - 0031-9007 .- 1079-7114. ; 126:14
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Tidskriftsartikel (refereegranskat)abstract
- We report the results of an experimental search for ultralight axionlike dark matter in the mass range 162-166 neV. The detection scheme of our Cosmic Axion Spin Precession Experiment is based on a precision measurement of Pb-207 solid-state nuclear magnetic resonance in a polarized ferroelectric crystal. Axionlike dark matter can exert an oscillating torque on Pb-20(7) nuclear spins via the electric dipole moment coupling g(d) or via the gradient coupling g(aNN). We calibrate the detector and characterize the excitation spectrum and relaxation parameters of the nuclear spin ensemble with pulsed magnetic resonance measurements in a 4.4 T magnetic field. We sweep the magnetic field near this value and search for axionlike dark matter with Compton frequency within a 1 MHz band centered at 39.65 MHz. Our measurements place the upper bounds vertical bar g(d)vertical bar < 9.5 x 10(-4) GeV-2 and vertical bar g(aNN)vertical bar( )< 2.8 x 10(-1) GeV-1 (95% confidence level) in this frequency range. The constraint on g d corresponds to an upper bound of 1.0 x 10(-21) e cm on the amplitude of oscillations of the neutron electric dipole moment and 4.3 x 10(-6) on the amplitude of oscillations of CP-violating theta parameter of quantum chromodynamics. Our results demonstrate the feasibility of using solid-state nuclear magnetic resonance to search for axionlike dark matter in the neV mass range.
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| 5. |
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| 6. |
- Centers, Gary P., et al.
(författare)
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Stochastic fluctuations of bosonic dark matter
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Numerous theories extending beyond the standard model of particle physics predict the existence of bosons that could constitute dark matter. In the standard halo model of galactic dark matter, the velocity distribution of the bosonic dark matter field defines a characteristic coherence time τc. Until recently, laboratory experiments searching for bosonic dark matter fields have been in the regime where the measurement time T significantly exceeds τc, so null results have been interpreted by assuming a bosonic field amplitude Φ0 fixed by the average local dark matter density. Here we show that experiments operating in the T ≪ τc regime do not sample the full distribution of bosonic dark matter field amplitudes and therefore it is incorrect to assume a fixed value of Φ0 when inferring constraints. Instead, in order to interpret laboratory measurements (even in the event of a discovery), it is necessary to account for the stochastic nature of such a virialized ultralight field. The constraints inferred from several previous null experiments searching for ultralight bosonic dark matter were overestimated by factors ranging from 3 to 10 depending on experimental details, model assumptions, and choice of inference framework.
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| 7. |
- Collins, Matthew D., et al.
(författare)
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Arsenicicoccus bolidensis gen. nov., sp nov., a novel actinomycete isolated from contaminated lake sediment
- 2004
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Ingår i: INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 54, s. 605-608
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Tidskriftsartikel (refereegranskat)abstract
- An unknown Gram-positive, catalase-positive, facultatively anaerobic, non-spore-forming, coccus-shaped bacterium originating from sediment was characterized using phenotypic, molecular chemical and molecular phylogenetic methods. Chemical studies revealed the presence of a cell-wall murein based on ll-diaminopimelic acid (type ll-Dpm-glycine1), a complex mixture of saturated, monounsaturated and iso- and anteiso-methyl-branched, non-hydroxylated, long-chain cellular fatty acids and tetrahydrogenated menaquinones with eight isoprene units [MK-8(H4)] as the major respiratory lipoquinone. This combination of characteristics somewhat resembled members of the suborder Micrococcineae, but did not correspond to any currently described species. Comparative 16S rRNA gene sequencing confirmed that the unidentified coccus-shaped organism is a member of the Actinobacteria and represents a hitherto-unknown subline related to, albeit different from, a number of taxa including Intrasporangium, Janibacter, Terrabacter, Terracoccus and Ornithinicoccus. Based on phenotypic and phylogenetic considerations, it is proposed that the unknown bacterium originating from lake sediment be classified as a new genus and species, Arsenicicoccus bolidensis gen. nov., sp. nov. (type strain CCUG 47306T=DSM 15745T).
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| 8. |
- Collins, Matthew D., et al.
(författare)
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Helcococcus sueciensis sp nov., isolated from a human wound
- 2004
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Ingår i: INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 54, s. 1557-1560
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Tidskriftsartikel (refereegranskat)abstract
- A previously undescribed, Gram-positive, catalase-negative, coccus-shaped organism that originated from a human wound was subjected to taxonomic study. On the basis of its cellular morphology and the results of biochemical testing, the unknown organism was identified tentatively as a member of the genus Helcococcus, but it did not correspond to either of the two recognized species of this genus. Comparative 16S rRNA gene sequencing studies confirmed that the bacterium was associated phylogenetically with the genus Helcococcus, with the unidentified organism forming a hitherto unknown subline within the genus. On the basis of biochemical, molecular chemical and molecular phylogenetic evidence, it is proposed that the unknown organism that was recovered from a human wound should be classified as a novel species of the genus Helcococcus, namely Helcococcus sueciensis sp. nov. The type strain is CCUG 47334T (=CIP 108183T).
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| 9. |
- Currie, Thayne, et al.
(författare)
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SCExAO/CHARIS Direct Imaging Discovery of a 20 au Separation, Low-mass Ratio Brown Dwarf Companion to an Accelerating Sun-like Star
- 2020
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 904:2
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Tidskriftsartikel (refereegranskat)abstract
- We present the direct imaging discovery of a substellar companion to the nearby Sun-like star, HD 33632 Aa, at a projected separation of similar to 20 au, obtained with SCExAO/CHARIS integral field spectroscopy complemented by Keck/NIRC2 thermal infrared imaging. The companion, HD 33632 Ab, induces a 10.5 sigma astrometric acceleration on the star as detected with the Gaia and Hipparcos satellites. SCExAO/CHARIS JHK (1.1-2.4 mu m) spectra and Keck/NIRC2 L-p (3.78 mu m) photometry are best matched by a field L/T transition object: an older, higher-gravity, and less dusty counterpart to HR 8799 cde. Combining our astrometry with Gaia/Hipparcos data and archival Lick Observatory radial velocities, we measure a dynamical mass of 46.4 8 M-J and an eccentricity of e < 0.46 at 95% confidence. HD 33632 Ab's mass and mass ratio (4.0% 0.7%) are comparable to the low-mass brown dwarf GJ 758 B and intermediate between the more massive brown dwarf HD 19467 B and the (near-)planet-mass companions to HR 2562 and GJ 504. Using Gaia to select for direct imaging observations with the newest extreme adaptive optics systems can reveal substellar or even planet-mass companions on solar system-like scales at an increased frequency compared to blind surveys.
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| 10. |
- Foster, Joshua W., et al.
(författare)
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Extraterrestrial Axion Search with the Breakthrough Listen Galactic Center Survey
- 2022
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Ingår i: Physical Review Letters. - : American Physical Society (APS). - 0031-9007 .- 1079-7114. ; 129:25
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Tidskriftsartikel (refereegranskat)abstract
- Axion dark matter (DM) may efficiently convert to photons in the magnetospheres of neutron stars (NSs), producing nearly monochromatic radio emission. This process is resonantly triggered when the plasma frequency induced by the underlying charge distribution approximately matches the axion mass. We search for evidence of this process using archival Green Bank Telescope data collected in a survey of the Galactic Center in the C band by the Breakthrough Listen project. While Breakthrough Listen aims to find signatures of extraterrestrial life in the radio band, we show that their high-frequency resolution spectral data of the Galactic Center region is ideal for searching for axion-photon transitions generated by the population of NSs in the inner pc of the Galaxy. We use data-driven models to capture the distributions and properties of NSs in the inner Galaxy and compute the expected radio flux from each NS using state-of-the-art ray tracing simulations. We find no evidence for axion DM and set leading constraints on the axion-photon coupling, excluding values down to the level ga gamma gamma similar to 10-11 GeV-1 for DM axions for masses between 15 and 35
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