| 1. |
- Tabiri, S, et al.
(författare)
-
- 2021
-
swepub:Mat__t
|
|
| 2. |
- Bravo, L, et al.
(författare)
-
- 2021
-
swepub:Mat__t
|
|
| 3. |
- Kanai, M, et al.
(författare)
-
- 2023
-
swepub:Mat__t
|
|
| 4. |
- Murari, A., et al.
(författare)
-
A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
-
Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Campbell, PJ, et al.
(författare)
-
Pan-cancer analysis of whole genomes
- 2020
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
-
Tidskriftsartikel (refereegranskat)abstract
- Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
|
|
| 9. |
|
|
| 10. |
- Santangelo, James S., et al.
(författare)
-
Global urban environmental change drives adaptation in white clover
- 2022
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 375
-
Tidskriftsartikel (refereegranskat)abstract
- Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural dines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.
|
|
| 11. |
- Mullins, Niamh, et al.
(författare)
-
Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors
- 2022
-
Ingår i: Biological Psychiatry. - : Elsevier. - 0006-3223 .- 1873-2402. ; 91:3, s. 313-327
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders.METHODS: We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors.RESULTS: Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged.CONCLUSIONS: Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.
|
|
| 12. |
- Docherty, Anna R, et al.
(författare)
-
GWAS Meta-Analysis of Suicide Attempt: Identification of 12 Genome-Wide Significant Loci and Implication of Genetic Risks for Specific Health Factors.
- 2023
-
Ingår i: The American journal of psychiatry. - : American Psychiatric Association Publishing. - 1535-7228 .- 0002-953X. ; 180:10, s. 723-738
-
Tidskriftsartikel (refereegranskat)abstract
- Suicidal behavior is heritable and is a major cause of death worldwide. Two large-scale genome-wide association studies (GWASs) recently discovered and cross-validated genome-wide significant (GWS) loci for suicide attempt (SA). The present study leveraged the genetic cohorts from both studies to conduct the largest GWAS meta-analysis of SA to date. Multi-ancestry and admixture-specific meta-analyses were conducted within groups of significant African, East Asian, and European ancestry admixtures.This study comprised 22 cohorts, including 43,871 SA cases and 915,025 ancestry-matched controls. Analytical methods across multi-ancestry and individual ancestry admixtures included inverse variance-weighted fixed-effects meta-analyses, followed by gene, gene-set, tissue-set, and drug-target enrichment, as well as summary-data-based Mendelian randomization with brain expression quantitative trait loci data, phenome-wide genetic correlation, and genetic causal proportion analyses.Multi-ancestry and European ancestry admixture GWAS meta-analyses identified 12 risk loci at p values <5×10-8. These loci were mostly intergenic and implicated DRD2, SLC6A9, FURIN, NLGN1, SOX5, PDE4B, and CACNG2. The multi-ancestry SNP-based heritability estimate of SA was 5.7% on the liability scale (SE=0.003, p=5.7×10-80). Significant brain tissue gene expression and drug set enrichment were observed. There was shared genetic variation of SA with attention deficit hyperactivity disorder, smoking, and risk tolerance after conditioning SA on both major depressive disorder and posttraumatic stress disorder. Genetic causal proportion analyses implicated shared genetic risk for specific health factors.This multi-ancestry analysis of suicide attempt identified several loci contributing to risk and establishes significant shared genetic covariation with clinical phenotypes. These findings provide insight into genetic factors associated with suicide attempt across ancestry admixture populations, in veteran and civilian populations, and in attempt versus death.
|
|
| 13. |
- Akiba, K., et al.
(författare)
-
The LHCb VELO Upgrade module construction
- 2024
-
Ingår i: Journal of Instrumentation. - : Institute of Physics Publishing (IOPP). - 1748-0221. ; 19:6
-
Tidskriftsartikel (refereegranskat)abstract
- The LHCb detector has undergone a major upgrade for LHC Run 3. This Upgrade I detector facilitates operation at higher luminosity and utilises full-detector information at the LHC collision rate, critically including the use of vertex information. A new vertex locator system, the VELO Upgrade, has been constructed. The core element of the new VELO are the double-sided pixelated hybrid silicon detector modules which operate in vacuum close to the LHC beam in a high radiation environment. The construction and quality assurance tests of these modules are described in this paper. The modules incorporate 200 mu m thick, n -on -p silicon sensors bump-bonded to 130 nm technology ASICs. These are attached with high precision to a silicon microchannel substrate that uses evaporative CO 2 cooling. The ASICs are controlled and read out with flexible printed circuits that are glued to the substrate and wire -bonded to the chips. The mechanical support of the module is given by a carbon fibre plate, two carbon fibre rods and an aluminium plate. The sensor attachment was achieved with an average precision of 21 mu m, more than 99.5% of all pixels are fully functional, and a thermal figure of merit of 3 Kcm 2 W - 1 was achieved. The production of the modules was successfully completed in 2021, with the final assembly and installation completed in time for data taking in 2022.
|
|
| 14. |
- Butler-Laporte, G, et al.
(författare)
-
Exome-wide association study to identify rare variants influencing COVID-19 outcomes: Results from the Host Genetics Initiative
- 2022
-
Ingår i: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404 .- 1553-7390. ; 18:11, s. e1010367-
-
Tidskriftsartikel (refereegranskat)abstract
- Host genetics is a key determinant of COVID-19 outcomes. Previously, the COVID-19 Host Genetics Initiative genome-wide association study used common variants to identify multiple loci associated with COVID-19 outcomes. However, variants with the largest impact on COVID-19 outcomes are expected to be rare in the population. Hence, studying rare variants may provide additional insights into disease susceptibility and pathogenesis, thereby informing therapeutics development. Here, we combined whole-exome and whole-genome sequencing from 21 cohorts across 12 countries and performed rare variant exome-wide burden analyses for COVID-19 outcomes. In an analysis of 5,085 severe disease cases and 571,737 controls, we observed that carrying a rare deleterious variant in the SARS-CoV-2 sensor toll-like receptor TLR7 (on chromosome X) was associated with a 5.3-fold increase in severe disease (95% CI: 2.75–10.05, p = 5.41x10-7). This association was consistent across sexes. These results further support TLR7 as a genetic determinant of severe disease and suggest that larger studies on rare variants influencing COVID-19 outcomes could provide additional insights.
|
|
| 15. |
|
|
| 16. |
- Sonderby, Ida E., et al.
(författare)
-
Dose response of the 16p11.2 distal copy number variant on intracranial volume and basal ganglia
- 2020
-
Ingår i: Molecular Psychiatry. - : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 25:3, s. 584-602
-
Tidskriftsartikel (refereegranskat)abstract
- Carriers of large recurrent copy number variants (CNVs) have a higher risk of developing neurodevelopmental disorders. The 16p11.2 distal CNV predisposes carriers to e.g., autism spectrum disorder and schizophrenia. We compared subcortical brain volumes of 12 16p11.2 distal deletion and 12 duplication carriers to 6882 non-carriers from the large-scale brain Magnetic Resonance Imaging collaboration, ENIGMA-CNV. After stringent CNV calling procedures, and standardized FreeSurfer image analysis, we found negative dose-response associations with copy number on intracranial volume and on regional caudate, pallidum and putamen volumes (β = −0.71 to −1.37; P < 0.0005). In an independent sample, consistent results were obtained, with significant effects in the pallidum (β = −0.95, P = 0.0042). The two data sets combined showed significant negative dose-response for the accumbens, caudate, pallidum, putamen and ICV (P = 0.0032, 8.9 × 10−6, 1.7 × 10−9, 3.5 × 10−12 and 1.0 × 10−4, respectively). Full scale IQ was lower in both deletion and duplication carriers compared to non-carriers. This is the first brain MRI study of the impact of the 16p11.2 distal CNV, and we demonstrate a specific effect on subcortical brain structures, suggesting a neuropathological pattern underlying the neurodevelopmental syndromes.
|
|
| 17. |
|
|
| 18. |
- Gonzalez-Ericsson, Paula, et al.
(författare)
-
The path to a better biomarker: application of a risk management framework for the implementation of PD‐L1 and TILs as immuno‐oncology biomarkers into breast cancer clinical trials and daily practice
- 2020
-
Ingår i: Journal of Pathology. - : Wiley. - 1096-9896 .- 0022-3417. ; 250:5, s. 667-684
-
Forskningsöversikt (refereegranskat)abstract
- Immune checkpoint inhibitor therapies targeting PD‐1/PD‐L1 are now the standard of care in oncology across several hematologic and solid tumor types, including triple negative breast cancer (TNBC). Patients with metastatic or locally advanced TNBC with PD‐L1 expression on immune cells occupying ≥1% of tumor area demonstrated survival benefit with the addition of atezolizumab to nab‐paclitaxel. However, concerns regarding variability between immunohistochemical PD‐L1 assay performance and inter‐reader reproducibility have been raised. High tumor‐infiltrating lymphocytes (TILs) have also been associated with response to PD‐1/PD‐L1 inhibitors in patients with breast cancer (BC). TILs can be easily assessed on hematoxylin and eosin–stained slides and have shown reliable inter‐reader reproducibility. As an established prognostic factor in early stage TNBC, TILs are soon anticipated to be reported in daily practice in many pathology laboratories worldwide. Because TILs and PD‐L1 are parts of an immunological spectrum in BC, we propose the systematic implementation of combined PD‐L1 and TIL analyses as a more comprehensive immuno‐oncological biomarker for patient selection for PD‐1/PD‐L1 inhibition‐based therapy in patients with BC. Although practical and regulatory considerations differ by jurisdiction, the pathology community has the responsibility to patients to implement assays that lead to optimal patient selection. We propose herewith a risk‐management framework that may help mitigate the risks of suboptimal patient selection for immuno‐therapeutic approaches in clinical trials and daily practice based on combined TILs/PD‐L1 assessment in BC.
|
|
| 19. |
|
|
| 20. |
- Rosa, M. J., et al.
(författare)
-
Identifying critical windows of prenatal particulate matter (PM2.5) exposure and early childhood blood pressure
- 2020
-
Ingår i: Environmental Research. - : Elsevier. - 0013-9351 .- 1096-0953. ; 182
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Exposure to air pollution is associated with increased blood pressure (BP) in adults and children. Some evidence suggests that air pollution exposure during the prenatal period may contribute to adverse cardiorenal health later in life. Here we apply a distributed lag model (DLM) approach to identify critical windows that may underlie the association between prenatal particulate matter ≤ 2.5 μm in diameter (PM2.5) exposure and children's BP at ages 4–6 years. Methods: Participants included 537 mother-child dyads enrolled in the Programming Research in Obesity, GRowth Environment, and Social Stress (PROGRESS) longitudinal birth cohort study based in Mexico City. Prenatal daily PM2.5 exposure was estimated using a validated satellite-based spatio-temporal model and BP was measured using the automated Spacelabs system with a sized cuff. We used distributed lag models (DLMs) to examine associations between daily PM2.5 exposure and systolic and diastolic BP (SBP and DBP), adjusting for child's age, sex and BMI, as well as maternal education, preeclampsia and indoor smoking report during the second and third trimester, seasonality and average postnatal year 1 PM2.5 exposure. Results: We found that PM2.5 exposure between weeks 11–32 of gestation (days 80–226) was significantly associated with children's increased SBP. Similarly, PM2.5 exposure between weeks 9–25 of gestation (days 63–176) was significantly associated with increased DBP. To place this into context, a constant 10 μg/m3 increase in PM2.5 sustained throughout this critical window would predict a cumulative increase of 2.6 mmHg (CI: 0.5, 4.6) in SBP and 0.88 mmHg (CI: 0.1, 1.6) in DBP at ages 4–6 years. In a stratified analysis by sex, this association persisted in boys but not in girls. Conclusions: Second and third trimester PM2.5 exposure may increase children's BP in early life. Further work investigating PM2.5 exposure with BP trajectories later in childhood will be important to understanding cardiorenal trajectories that may predict adult disease. Our results underscore the importance of reducing air pollution exposure among susceptible populations, including pregnant women.
|
|
| 21. |
- Zavala, J. A., et al.
(författare)
-
The Evolution of the IR Luminosity Function and Dust-obscured Star Formation over the Past 13 Billion Years
- 2021
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 909:2
-
Tidskriftsartikel (refereegranskat)abstract
- We present the first results from the Mapping Obscuration to Reionization with ALMA (MORA) survey, the largest Atacama Large Millimeter/submillimeter Array (ALMA) blank-field contiguous survey to date (184 arcmin(2)) and the only at 2 mm to search for dusty star-forming galaxies (DSFGs). We use the 13 sources detected above 5 sigma to estimate the first ALMA galaxy number counts at this wavelength. These number counts are then combined with the state-of-the-art galaxy number counts at 1.2 and 3 mm and with a backward evolution model to place constraints on the evolution of the IR luminosity function and dust-obscured star formation in the past 13 billion years. Our results suggest a steep redshift evolution on the space density of DSFGs and confirm the flattening of the IR luminosity function at faint luminosities, with a slope of alpha(LF) = -0.42(-0.04)(+0.02). We conclude that the dust-obscured component, which peaks at z approximate to 2-2.5, has dominated the cosmic history of star formation for the past similar to 12 billion years, back to z similar to 4. At z = 5, the dust-obscured star formation is estimated to be similar to 35% of the total star formation rate density and decreases to 25%-20% at z = 6-7, implying a minor contribution of dusten-shrouded star formation in the first billion years of the universe. With the dust-obscured star formation history constrained up to the end of the epoch of reionization, our results provide a benchmark to test galaxy formation models, to study the galaxy mass assembly history, and to understand the dust and metal enrichment of the universe at early times.
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
- Clark, M. S., et al.
(författare)
-
Deciphering mollusc shell production: the roles of genetic mechanisms through to ecology, aquaculture and biomimetics
- 2020
-
Ingår i: Biological Reviews. - : Wiley. - 1464-7931 .- 1469-185X. ; 95:6, s. 1812-37
-
Tidskriftsartikel (refereegranskat)abstract
- Most molluscs possess shells, constructed from a vast array of microstructures and architectures. The fully formed shell is composed of calcite or aragonite. These CaCO(3)crystals form complex biocomposites with proteins, which although typically less than 5% of total shell mass, play significant roles in determining shell microstructure. Despite much research effort, large knowledge gaps remain in how molluscs construct and maintain their shells, and how they produce such a great diversity of forms. Here we synthesize results on how shell shape, microstructure, composition and organic content vary among, and within, species in response to numerous biotic and abiotic factors. At the local level, temperature, food supply and predation cues significantly affect shell morphology, whilst salinity has a much stronger influence across latitudes. Moreover, we emphasize how advances in genomic technologies [e.g. restriction site-associated DNA sequencing (RAD-Seq) and epigenetics] allow detailed examinations of whether morphological changes result from phenotypic plasticity or genetic adaptation, or a combination of these. RAD-Seq has already identified single nucleotide polymorphisms associated with temperature and aquaculture practices, whilst epigenetic processes have been shown significantly to modify shell construction to local conditions in, for example, Antarctica and New Zealand. We also synthesize results on the costs of shell construction and explore how these affect energetic trade-offs in animal metabolism. The cellular costs are still debated, with CaCO(3)precipitation estimates ranging from 1-2 J/mg to 17-55 J/mg depending on experimental and environmental conditions. However, organic components are more expensive (similar to 29 J/mg) and recent data indicate transmembrane calcium ion transporters can involve considerable costs. This review emphasizes the role that molecular analyses have played in demonstrating multiple evolutionary origins of biomineralization genes. Although these are characterized by lineage-specific proteins and unique combinations of co-opted genes, a small set of protein domains have been identified as a conserved biomineralization tool box. We further highlight the use of sequence data sets in providing candidate genes forin situlocalization and protein function studies. The former has elucidated gene expression modularity in mantle tissue, improving understanding of the diversity of shell morphology synthesis. RNA interference (RNAi) and clustered regularly interspersed short palindromic repeats - CRISPR-associated protein 9 (CRISPR-Cas9) experiments have provided proof of concept for use in the functional investigation of mollusc gene sequences, showing for example that Pif (aragonite-binding) protein plays a significant role in structured nacre crystal growth and that theLsdia1gene sets shell chirality inLymnaea stagnalis. Much research has focused on the impacts of ocean acidification on molluscs. Initial studies were predominantly pessimistic for future molluscan biodiversity. However, more sophisticated experiments incorporating selective breeding and multiple generations are identifying subtle effects and that variability within mollusc genomes has potential for adaption to future conditions. Furthermore, we highlight recent historical studies based on museum collections that demonstrate a greater resilience of molluscs to climate change compared with experimental data. The future of mollusc research lies not solely with ecological investigations into biodiversity, and this review synthesizes knowledge across disciplines to understand biomineralization. It spans research ranging from evolution and development, through predictions of biodiversity prospects and future-proofing of aquaculture to identifying new biomimetic opportunities and societal benefits from recycling shell products.
|
|
| 26. |
|
|
| 27. |
|
|
| 28. |
|
|
| 29. |
- Manning, Sinclaire M., et al.
(författare)
-
Characterization of Two 2 mm detected Optically Obscured Dusty Star-forming Galaxies
- 2022
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 925:1
-
Tidskriftsartikel (refereegranskat)abstract
- The 2 mm Mapping Obscuration to Reionization with ALMA (MORA) Survey was designed to detect high-redshift (z greater than or similar to 4), massive, dusty star-forming galaxies (DSFGs). Here we present two likely high-redshift sources, identified in the survey, whose physical characteristics are consistent with a class of optical/near-infrared (OIR)-invisible DSFGs found elsewhere in the literature. We first perform a rigorous analysis of all available photometric data to fit spectral energy distributions and estimate redshifts before deriving physical properties based on our findings. Our results suggest the two galaxies, called MORA-5 and MORA-9, represent two extremes of the "OIR-dark" class of DSFGs. MORA-5 (z(phot) = 4.3(-1.3)(+1.5)) is a significantly more active starburst with a star formation rate (SFR) of 830(-190)(+340) M-circle dot yr(-1) compared to MORA-9 (z(phot) = 4.3(-1.0)(+1.3)), whose SFR is a modest 200(-60)(+250) M-circle dot yr(-1). Based on the stellar masses (M-star approximate to 10(10-11) M-circle dot), space density (n similar to (5 +/- 2) x 10(-6) Mpc(-3), which incorporates two other spectroscopically confirmed OIR-dark DSFGs in the MORA sample at z = 4.6 and z = 5.9), and gas depletion timescales (<1 Gyr) of these sources, we find evidence supporting the theory that OIR-dark DSFGs are the progenitors of recently discovered 3 < z < 4 massive quiescent galaxies.
|
|
| 30. |
- Maxwell, Tania L., et al.
(författare)
-
Global dataset of soil organic carbon in tidal marshes
- 2023
-
Ingår i: Scientific Data. - : Springer Nature. - 2052-4463. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha−1 in the top 30 cm and 231 ± 134 Mg SOC ha−1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies.
|
|
| 31. |
- Amora-Nogueira, Leonardo, et al.
(författare)
-
Linking centennial scale anthropogenic changes and sedimentary records as lessons for urban coastal management
- 2023
-
Ingår i: Science of the Total Environment. - : ELSEVIER. - 0048-9697 .- 1879-1026. ; 902
-
Tidskriftsartikel (refereegranskat)abstract
- Coastal eutrophication and urban flooding are increasingly important components of global change. Although increased seawater renewal by barrier openings and channelizing are common mitigation measures in coastal lagoons worldwide, their effects on these ecosystems are not fully understood. Here, we evaluated the re-lationships between human interventions in the watershed, artificial connections to the sea, and the sediment burial rates in an urban coastal lagoon (Maric & PRIME;a lagoon, Southeastern Brazil). Sediment accretion along with nutrient and carbon burial rates were determined in two sediment cores representing the past-120 years (210Pb dating) and associated with anthropogenic changes as indicated by historical records and geoinformation ana-lyses. Lagoon infilling and eutrophication, expressed by the average sediment accretion, TP, TN, and OC burial rates, respectively, increased-9-18, 13-15, 11-14 and 11-12-fold from the earliest (<1950) to the most recent (2000-2017) period. These multi-proxy records confirm mechanistic links between deforestation, urbanization, and untreated sewage discharges. In addition, our findings reveal artificial connections to the sea may contribute to lagoonal eutrophication and infilling, particularly when not integrated with sewage treatment and forest conservation or reforestation in the watershed. Therefore, increased seawater renewal by physical interventions commonly considered as mitigation measures may in contrast cause severe degradation in coastal lagoons, causing harmful consequences that should be not neglected when implementing management practices.
|
|
| 32. |
- Brown, Dylan R., et al.
(författare)
-
Hypersaline tidal flats as important "blue carbon" systems : a case study from three ecosystems
- 2021
-
Ingår i: Biogeosciences. - : COPERNICUS GESELLSCHAFT MBH. - 1726-4170 .- 1726-4189. ; 18:8, s. 2527-2538
-
Tidskriftsartikel (refereegranskat)abstract
- Hypersaline tidal flats (HTFs) are coastal ecosystems with freshwater deficits often occurring in arid or semiarid regions near mangrove supratidal zones with no major fluvial contributions. Here, we estimate that organic carbon (OC), total nitrogen (TN) and total phosphorus (TP) were buried at rates averaging 21 (+/- 6), 1.7 (+/- 0.3) and 1.4 (+/- 0.3) gm(-2) yr(-1), respectively, during the previous century in three contrasting HTF systems, one in Brazil (eutrophic) and two in Australia (oligotrophic). Although these rates are lower than those from nearby mangrove, saltmarsh and seagrass systems, the importance of HTFs as sinks for OC, TN and TP may be significant given their extensive coverage. Despite the measured short-term variability between net air-saltpan CO2 influx and emission estimates found during the dry and wet season in the Brazilian HTF, the only site with seasonal CO2 flux measurements, the OC sedimentary profiles over several decades suggest efficient OC burial at all sites. Indeed, the stable isotopes of OC and TN (delta C-13 and delta N-1(5)) along with C : N ratios show that microphytobenthos are the major source of the buried OC in these HTFs. Our findings highlight a previously unquantified carbon as well as a nutrient sink and suggest that coastal HTF ecosystems could be included in the emerging blue carbon framework.
|
|
| 33. |
- Heintz, K. E., et al.
(författare)
-
The Gas and Stellar Content of a Metal-poor Galaxy at z = 8.496 as Revealed by JWST and ALMA
- 2023
-
Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 944:2
-
Tidskriftsartikel (refereegranskat)abstract
- We present a joint analysis of the galaxy S04590 at z = 8.496 based on NIRSpec, NIRCam, and NIRISS observations obtained as part of the Early Release Observations program of the James Webb Space Telescope (JWST) and the far-infrared [C ii] 158 μm emission line detected by dedicated Atacama Large Millimeter/submillimeter Array (ALMA) observations. We determine the physical properties of S04590 from modeling of the spectral energy distribution (SED) and through the redshifted optical nebular emission lines detected with JWST/NIRSpec. The best-fit SED model reveals a low-mass (M ⋆ = 107.2-108 M ⊙) galaxy with a low oxygen abundance of 12 + log ( O / H ) = 7.16 − 0.12 + 0.10 derived from the strong nebular and auroral emission lines. Assuming that [C ii] effectively traces the interstellar medium, we estimate the total gas mass of the galaxy to be M gas = (8.0 ± 4.0) × 108 M ⊙ based on the luminosity and spatial extent of [C ii]. This yields an exceptionally high gas fraction, f gas = M gas/(M gas + M ⋆) ≳ 90%, though one still consistent with the range expected for low metallicity. We further derive the metal mass of the galaxy based on the gas mass and gas-phase metallicity, which we find to be consistent with the expected metal production from Type II supernovae. Finally, we make the first constraints on the dust-to-gas (DTG) and dust-to-metal (DTM) ratios of galaxies in the epoch of reionization at z ≳ 6, showing overall low mass ratios of logDTG < −3.8 and logDTM < −0.5, though they are consistent with established scaling relations and in particular with those of the local metal-poor galaxy I Zwicky 18. Our analysis highlights the synergy between ALMA and JWST in characterizing the gas, metal, and stellar content of the first generation of galaxies.
|
|
| 34. |
|
|
| 35. |
|
|
| 36. |
|
|
| 37. |
- Ohm, Milou, et al.
(författare)
-
Different Long-Term Duration of Seroprotection against Neisseria meningitidis in Adolescents and Middle-Aged Adults after a Single Meningococcal ACWY Conjugate Vaccination in The Netherlands
- 2020
-
Ingår i: Vaccines. - : MDPI AG. - 2076-393X. ; 8:4
-
Tidskriftsartikel (refereegranskat)abstract
- Neisseria meningitidis is often asymptomatically carried in the nasopharynx but may cause invasive meningococcal disease, leading to morbidity and mortality. Meningococcal conjugate vaccinations induce functional protective antibodies against capsular antigens, but seroprotection wanes over time. We measured functional antibody titers five years after administration of a single dose of the meningococcal ACWY-polysaccharide-specific tetanus toxoid-conjugated (MenACWY-TT) vaccine in adolescents and middle-aged adults in the Netherlands, using the serum bactericidal antibody with baby rabbit complement (rSBA) assay. Protection was defined as rSBA titer >= 8. The meningococcal ACWY-specific serum IgG concentrations were measured with a multiplex immunoassay. Duration of protection was estimated by a bi-exponential decay model. Sufficient protection for MenC, MenW, and MenY was achieved in 94-96% of the adolescents five years postvaccination, but, in middle-aged adults, only in 32% for MenC, 65% for MenW and 71% for MenY. Median duration of protection for MenCWY was 4, 14, and 21 years, respectively, in middle-aged adults, while, in adolescents, it was 32, 98, and 33 years. Our findings suggest that adolescents, primed in early childhood with MenC conjugate vaccination, remain sufficiently protected after a single dose of MenACWY-TT vaccine. Middle-aged adults without priming vaccination show fast waning of antibodies, particularly MenC, for which protection is lost after four years.
|
|
| 38. |
- Reiss, EIMM, et al.
(författare)
-
Fine-mapping the immunodominant antibody epitopes on consensus sequence-based HIV-1 envelope trimer vaccine candidates
- 2022
-
Ingår i: NPJ vaccines. - : Springer Science and Business Media LLC. - 2059-0105. ; 7:1, s. 152-
-
Tidskriftsartikel (refereegranskat)abstract
- The HIV-1 envelope glycoprotein (Env) trimer is the key target for vaccines aimed at inducing neutralizing antibodies (NAbs) against HIV-1. The clinical candidate immunogen ConM SOSIP.v7 is a stabilized native-like HIV-1 Env trimer based on an artificial consensus sequence of all HIV-1 isolates in group M. In preclinical studies ConM SOSIP.v7 trimers induced strong autologous NAb responses in non-human primates (NHPs). To fine-map these responses, we isolated monoclonal antibodies (mAbs) from six cynomolgus macaques that were immunized three times with ConM SOSIP.v7 protein and boosted twice with the closely related ConSOSL.UFO.664 immunogen. A total of 40 ConM and/or ConS-specific mAbs were isolated, of which 18 were retrieved after the three ConM SOSIP.v7 immunizations and 22 after the two immunizations with ConSOSL.UFO.664. 22 mAbs (55%) neutralized the ConM and/or ConS virus. Cross-neutralization of ConS virus by approximately one-third of the mAbs was seen prior to ConSOSL.UFO.664 immunization, albeit with modest potency. Neutralizing antibodies predominantly targeted the V1 and V2 regions of the immunogens, with an apparent extension towards the V3 region. Thus, the V1V2V3 region is immunodominant in the potent NAb response elicited by two consensus sequence native-like HIV-1 Env immunogens. Immunization with these soluble consensus Env proteins also elicited non-neutralizing mAbs targeting the trimer base. These results inform the use and improvement of consensus-based trimer immunogens in combinatorial vaccine strategies.
|
|
| 39. |
|
|
| 40. |
- Simons, Sami O., et al.
(författare)
-
Chronic obstructive pulmonary disease and atrial fibrillation an interdisciplinary perspective
- 2021
-
Ingår i: European Heart Journal. - : OXFORD UNIV PRESS. - 0195-668X .- 1522-9645. ; 42:5
-
Forskningsöversikt (refereegranskat)abstract
- Chronic obstructive pulmonary disease (COPD) is highly prevalent among patients with atrial fibrillation (AF), shares common risk factors, and adds to the overall morbidity and mortality in this population. Additionally, it may promote AF and impair treatment efficacy. The prevalence of COPD in AF patients is high and is estimated to be similar to 25%. Diagnosis and treatment of COPD in AF patients requires a close interdisciplinary collaboration between the electrophysiologist/cardiologist and pulmonologist. Differential diagnosis may be challenging, especially in elderly and smoking patients complaining of unspecific symptoms such as dyspnoea and fatigue. Routine evaluation of lung function and determination of natriuretic peptides and echocardiography may be reasonable to detect COPD and heart failure as contributing causes of dyspnoea. Acute exacerbation of COPD transiently increases AF risk due to hypoxia-mediated mechanisms, inflammation, increased use of beta-2 agonists, and autonomic changes. Observational data suggest that COPD promotes AF progression, increases AF recurrence after cardioversion, and reduces the efficacy of catheter-based antiarrhythmic therapy. However, it remains unclear whether treatment of COPD improves AF outcomes and which metric should be used to determine COPD severity and guide treatment in AF patients. Data from non-randomized studies suggest that COPD is associated with increased AF recurrence after electrical cardioversion and catheter ablation. Future prospective cohort studies in AF patients are needed to confirm the relationship between COPD and AF, the benefits of treatment of either COPD or AF in this population, and to clarify the need and cost-effectiveness of routine COPD screening.
|
|
| 41. |
- Thurik, A. R., et al.
(författare)
-
The impact of entrepreneurship research on other academic fields
- 2023
-
Ingår i: Small Business Economics. - : Springer. - 0921-898X .- 1573-0913.
-
Tidskriftsartikel (refereegranskat)abstract
- The remarkable ascent of entrepreneurship witnessed as a scientific field over the last 4 decades has been made possible by entrepreneurship’s ability to absorb theories, paradigms, and methods from other fields such as economics, psychology, sociology, geography, and even biology. The respectability of entrepreneurship as an academic discipline is now evidenced by many other fields starting to borrow from the entrepreneurship view. In the present paper, seven examples are given from this “pay back” development. These examples were first presented during a seminar at the Erasmus Entrepreneurship Event called what has the entrepreneurship view to offer to other academic fields? This article elaborates on the core ideas of these presentations and focuses on the overarching question of how entrepreneurship research impacts the development of other academic fields. We found that entrepreneurship research questions the core assumptions of other academic fields and provides new insights into the antecedents, mechanisms, and consequences of their respective core phenomena. Moreover, entrepreneurship research helps to legitimize other academic fields both practically and academically.
|
|
| 42. |
|
|
| 43. |
- Wang, F. M., et al.
(författare)
-
Global blue carbon accumulation in tidal wetlands increases with climate change
- 2021
-
Ingår i: National Science Review. - : Oxford University Press (OUP). - 2095-5138 .- 2053-714X. ; 8:9
-
Tidskriftsartikel (refereegranskat)abstract
- Coastal tidal wetlands produce and accumulate significant amounts of organic carbon (C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65 (95%CI: 48.52-59.01) Tg C yr(-1), which is similar to 30% of the organic C buried on the ocean floor. Modeling based on current climatic drivers and under projected emissions scenarios revealed a net increase in the global C accumulation by 2100. This rapid increase is driven by sea level rise in tidal marshes, and higher temperature and precipitation in mangroves. Countries with large areas of coastal wetlands, like Indonesia and Mexico, are more susceptible to tidal wetland C losses under climate change, while regions such as Australia, Brazil, the USA and China will experience a significant C accumulation increase under all projected scenarios.
|
|
| 44. |
- Armus, Lee, et al.
(författare)
-
GOALS-JWST: Mid-infrared Spectroscopy of the Nucleus of NGC 7469
- 2023
-
Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 942:2
-
Tidskriftsartikel (refereegranskat)abstract
- We present mid-infrared spectroscopic observations of the nucleus of the nearby Seyfert galaxy NGC 7469 taken with the MIRI instrument on the James Webb Space Telescope (JWST) as part of Directors Discretionary Time Early Release Science program 1328. The high-resolution nuclear spectrum contains 19 emission lines covering a wide range of ionization. The high-ionization lines show broad, blueshifted emission reaching velocities up to 1700 km s−1 and FWHM ranging from ∼500 to 1100 km s−1. The width of the broad emission and the broad-to-narrow line flux ratios correlate with ionization potential. The results suggest a decelerating, stratified, AGN-driven outflow emerging from the nucleus. The estimated mass outflow rate is 1-2 orders of magnitude larger than the current black hole accretion rate needed to power the AGN. Eight pure rotational H2 emission lines are detected with intrinsic widths ranging from FWHM ∼125 to 330 km s−1. We estimate a total mass of warm H2 gas of ∼1.2 × 107 M ⊙ in the central 100 pc. The PAH features are extremely weak in the nuclear spectrum, but a 6.2 μm PAH feature with an equivalent width of ∼0.07 μm and a flux of 2.7 × 10−17 W m−2 is detected. The spectrum is steeply rising in the mid-infrared, with a silicate strength of ∼0.02, significantly smaller than seen in most PG QSOs but comparable to other Seyfert 1s. These early MIRI mid-infrared IFU data highlight the power of JWST to probe the multiphase interstellar media surrounding actively accreting supermassive black holes.
|
|
| 45. |
- Bianchin, Marina, et al.
(författare)
-
GOALS-JWST: Gas Dynamics and Excitation in NGC 7469 Revealed by NIRSpec
- 2024
-
Ingår i: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 965:2
-
Tidskriftsartikel (refereegranskat)abstract
- We present new JWST NIRSpec integral field spectroscopy (IFS) data for the luminous infrared galaxy NGC 7469, a nearby (70.6 Mpc) active galaxy with a Seyfert 1.5 nucleus that drives a highly ionized gas outflow and a prominent nuclear star-forming ring. Using the superb sensitivity and high spatial resolution of the JWST instrument NIRSpec IFS, we investigate the role of the Seyfert nucleus in the excitation and dynamics of the circumnuclear gas. Our analysis focuses on the [Fe ii], H2, and hydrogen recombination lines that trace the radiation/shocked-excited molecular and ionized interstellar medium around the active galactic nucleus (AGN). We investigate gas excitation through H2/Brγ and [Fe ii]/Paβ emission line ratios and find that photoionization by the AGN dominates within the central 300 pc of the galaxy except in a small region that shows signatures of shock-heated gas; these shock-heated regions are likely associated with a compact radio jet. In addition, the velocity field and velocity dispersion maps reveal complex gas kinematics. Rotation is the dominant feature, but we also identify noncircular motions consistent with gas inflows as traced by the velocity residuals and the spiral pattern in the Paα velocity dispersion map. The inflow is 2 orders of magnitude higher than the AGN accretion rate. The compact nuclear radio jet has enough power to drive the highly ionized outflow. This scenario suggests that the inflow and outflow are in a self-regulating feeding-feedback process, with a contribution from the radio jet helping to drive the outflow.
|
|
| 46. |
- Bohn, Thomas, et al.
(författare)
-
GOALS-JWST: NIRCam and MIRI Imaging of the Circumnuclear Starburst Ring in NGC 7469
- 2023
-
Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 942:2
-
Tidskriftsartikel (refereegranskat)abstract
- We present James Webb Space Telescope (JWST) imaging of NGC 7469 with the Near-Infrared Camera and the Mid-InfraRed Instrument. NGC 7469 is a nearby, z = 0.01627, luminous infrared galaxy that hosts both a Seyfert Type-1.5 nucleus and a circumnuclear starburst ring with a radius of ∼0.5 kpc. The new near-infrared (NIR) JWST imaging reveals 66 star-forming regions, 37 of which were not detected by Hubble Space Telescope (HST) observations. Twenty-eight of the 37 sources have very red NIR colors that indicate obscurations up to A v ∼ 7 and a contribution of at least 25% from hot dust emission to the 4.4 μm band. Their NIR colors are also consistent with young (<5 Myr) stellar populations and more than half of them are coincident with the mid-infrared (MIR) emission peaks. These younger, dusty star-forming regions account for ∼6% and ∼17% of the total 1.5 and 4.4 μm luminosity of the starburst ring, respectively. Thanks to JWST, we find a significant number of young dusty sources that were previously unseen due to dust extinction. The newly identified 28 young sources are a significant increase compared to the number of HST-detected young sources (4-5). This makes the total percentage of the young population rise from ∼15% to 48%. These results illustrate the effectiveness of JWST in identifying and characterizing previously hidden star formation in the densest star-forming environments around active galactic nuclei (AGN).
|
|
| 47. |
- Chen, X. G., et al.
(författare)
-
The mangrove CO2 pump: Tidally driven pore-water exchange
- 2021
-
Ingår i: Limnology and Oceanography. - : Wiley. - 0024-3590 .- 1939-5590. ; 66:4, s. 1563-1577
-
Tidskriftsartikel (refereegranskat)abstract
- Atmospheric carbon dioxide (CO2) is fixed by mangrove vegetation and stored in its biomass and sediments. Part of the sediment carbon can be exported to coastal waters via tidally driven pore-water exchange. Here, we quantify pore water-derived dissolved CO2 export using in situ, high-resolution observations of Rn-222 and CO2 over a spring-neap tidal cycle in a mangrove-fringed estuary (Coffs Creek, Australia). Rn-222-derived pore-water exchange rates were 11.5-34.9 cm d(-1) (23.0 +/- 6.7) over 30 tidal cycles. Pore-water exchange released CO2 from intertidal sediment at rates of 61-213 (136 +/- 43) mmol m(-2) d(-1). This is equivalent to similar to 94% of the total CO2 input into the estuary and approximately two times of the water-atmosphere CO2 emission. These observations reveal that tidal pumping is a major regulator of both mangrove pore-water exchange and associated dissolved CO2 export to the ocean. Combining our estimates with literature data, a first-order global pore water-derived dissolved CO2 export from mangroves was estimated to be 83 +/- 50 Tg C yr(-1). This is higher than an earlier estimates of global mangrove CO2 emissions to the atmosphere (34.1 +/- 5.4 Tg C yr(-1)) and carbon burial in sediments (18.4-34.4 Tg C yr(-1)), implying that pore water-derived CO2 escapes to the atmosphere within and beyond mangrove waters. Overall, CO2-rich pore water seems to be a widespread, important pathway of CO2 into mangrove-dominated estuaries and should be considered in mangrove carbon assessments in the context of global climate change and blue carbon.
|
|
| 48. |
- Córdova-Palomera, Aldo, et al.
(författare)
-
Genetic control of variability in subcortical and intracranial volumes
- 2021
-
Ingår i: Molecular Psychiatry. - : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 26:8, s. 3876-3883
-
Tidskriftsartikel (refereegranskat)abstract
- Sensitivity to external demands is essential for adaptation to dynamic environments, but comes at the cost of increased risk of adverse outcomes when facing poor environmental conditions. Here, we apply a novel methodology to perform genome-wide association analysis of mean and variance in ten key brain features (accumbens, amygdala, caudate, hippocampus, pallidum, putamen, thalamus, intracranial volume, cortical surface area, and cortical thickness), integrating genetic and neuroanatomical data from a large lifespan sample (n = 25,575 individuals; 8-89 years, mean age 51.9 years). We identify genetic loci associated with phenotypic variability in thalamus volume and cortical thickness. The variance-controlling loci involved genes with a documented role in brain and mental health and were not associated with the mean anatomical volumes. This proof-of-principle of the hypothesis of a genetic regulation of brain volume variability contributes to establishing the genetic basis of phenotypic variance (i.e., heritability), allows identifying different degrees of brain robustness across individuals, and opens new research avenues in the search for mechanisms controlling brain and mental health.
|
|
| 49. |
- Evans, Aaron S., et al.
(författare)
-
GOALS-JWST: Hidden Star Formation and Extended PAH Emission in the Luminous Infrared Galaxy VV 114
- 2022
-
Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 940:1
-
Tidskriftsartikel (refereegranskat)abstract
- James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) images of the luminous infrared (IR) galaxy VV 114 are presented. This redshift ∼0.020 merger has a western component (VV 114W) rich in optical star clusters and an eastern component (VV 114E) hosting a luminous mid-IR nucleus hidden at UV and optical wavelengths by dust lanes. With MIRI, the VV 114E nucleus resolves primarily into bright NE and SW cores separated by 630 pc. This nucleus comprises 45% of the 15 μm light of VV 114, with the NE and SW cores having IR luminosities, L IR(8 − 1000 μm) ∼ 8 ± 0.8 × 1010 L ⊙ and ∼ 5 ± 0.5 × 1010 L ⊙, respectively, and IR densities, ΣIR ≳ 2 ± 0.2 × 1013 L ⊙ kpc−2 and ≳ 7 ± 0.7 × 1012 L ⊙ kpc−2, respectively—in the range of ΣIR for the Orion star-forming core and the nuclei of Arp 220. The NE core, previously speculated to have an active galactic nucleus (AGN), has starburst-like mid-IR colors. In contrast, the VV 114E SW core has AGN-like colors. Approximately 40 star-forming knots with L IR ∼ 0.02-5 × 1010 L ⊙ are identified, 28% of which have no optical counterpart. Finally, diffuse emission accounts for 40%-60% of the mid-IR emission. Mostly notably, filamentary polycyclic aromatic hydrocarbon (PAH) emission stochastically excited by UV and optical photons accounts for half of the 7.7 μm light of VV 114. This study illustrates the ability of JWST to detect obscured compact activity and distributed PAH emission in the most extreme starburst galaxies in the local universe.
|
|
| 50. |
- Garcia-Martin, E. Elena, et al.
(författare)
-
Sources, Composition, and Export of Particulate Organic Matter Across British Estuaries
- 2023
-
Ingår i: Journal of Geophysical Research - Biogeosciences. - : American Geophysical Union (AGU). - 2169-8953 .- 2169-8961. ; 128:4
-
Tidskriftsartikel (refereegranskat)abstract
- Estuaries receive and process a large amount of particulate organic carbon (POC) prior to its export into coastal waters. Studying the origin of this POC is key to understanding the fate of POC and the role of estuaries in the global carbon cycle. Here, we evaluated the concentrations of POC, as well as particulate organic nitrogen (PON), and used stable carbon and nitrogen isotopes to assess their sources across 13 contrasting British estuaries during five different sampling campaigns over 1 year. We found a high variability in POC and PON concentrations across the salinity gradient, reflecting inputs, and losses of organic material within the estuaries. Catchment land cover appeared to influence the contribution of POC to the total organic carbon flux from the estuary to coastal waters, with POC contributions >36% in estuaries draining catchments with a high percentage of urban/suburban land, and <11% in estuaries draining catchments with a high peatland cover. There was no seasonal pattern in the isotopic composition of POC and PON, suggesting similar sources for each estuary over time. Carbon isotopic ratios were depleted (-26.7 +/- 0.42 parts per thousand, average +/- sd) at the lowest salinity waters, indicating mainly terrigenous POC (TPOC). Applying a two-source mixing model, we observed high variability in the contribution of TPOC at the highest salinity waters between estuaries, with a median value of 57%. Our results indicate a large transport of terrigenous organic carbon into coastal waters, where it may be buried, remineralized, or transported offshore. Plain Language Summary Estuaries transport and process a large amount terrigenous particulate organic matter (i.e., carbon and nitrogen) prior to its export to coastal waters. In order to understand the fate of organic carbon and the role of estuaries in the global carbon cycle it is essential to improve our knowledge on its composition, origin, and amount of carbon transported. We quantified the elemental concentrations and stable isotopes composition of carbon and nitrogen to quantify the amount of terrigenous particulate organic matter transported by 13 British estuaries, which drain catchments of diverse land cover under different hydrological conditions. We found a great variability in particulate organic carbon (POC) and particulate organic nitrogen concentrations across the salinity gradient, implying inputs, and losses of material within the estuaries. Each estuary had similar sources of particulate material throughout the year. In most of the estuaries, the POC had a terrigenous origin at the lowest salinity waters. The terrigenous organic carbon contribution decreased toward coastal waters with an average contribution of 57% at the highest salinity waters, indicating a large transport of terrigenous organic carbon into coastal waters.
|
|
