| 1. |
- Ritscher, Amélie, et al.
(författare)
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Zurich Statement on Future Actions on Per - and Polyfluoroalkyl Substances (PFASs)
- 2018
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Ingår i: Journal of Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 126:8
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Tidskriftsartikel (refereegranskat)abstract
- Per - and polyfluoroalkyl substances (PFASs) are man-made chemicals that contain at least one perfluoroalkyl moiety, -CnF2n-. To date, over 4,000 unique PFASs have been used in technical applications and consumer products, and some of them have been detected globally in human and wildlife biomonitoring studies. Because of their extraordinary persistence, human and environmental exposure to PFASs will be a long-term source of concern. Some PFASs such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) have been investigated extensively and thus regulated, but for many other PFASs, knowledge about their current uses and hazards is still very limited or missing entirely. To address this problem and prepare an action plan for the assessment and management of PFASs in the coming years, a group of more than 50 international scientists and regulators held a two-day workshop in November, 2017. The group identified both the respective needs of and common goals shared by the scientific and the policy communities, made recommendations for cooperative actions, and outlined how the science-policy interface regarding PFASs can be strengthened using new approaches for assessing and managing highly persistent chemicals such as PFASs.
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| 2. |
- Tiegs, Scott D., et al.
(författare)
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Global patterns and drivers of ecosystem functioning in rivers and riparian zones
- 2019
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Ingår i: Science Advances. - Washington : American Association of Advancement in Science. - 2375-2548. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.
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| 3. |
- Costello, David M., et al.
(författare)
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Global patterns and controls of nutrient immobilization on decomposing cellulose in riverine ecosystems
- 2022
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Ingår i: Global Biogeochemical Cycles. - : John Wiley & Sons. - 0886-6236 .- 1944-9224. ; 36:3
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Tidskriftsartikel (refereegranskat)abstract
- Microbes play a critical role in plant litter decomposition and influence the fate of carbon in rivers and riparian zones. When decomposing low-nutrient plant litter, microbes acquire nitrogen (N) and phosphorus (P) from the environment (i.e., nutrient immobilization), and this process is potentially sensitive to nutrient loading and changing climate. Nonetheless, environmental controls on immobilization are poorly understood because rates are also influenced by plant litter chemistry, which is coupled to the same environmental factors. Here we used a standardized, low-nutrient organic matter substrate (cotton strips) to quantify nutrient immobilization at 100 paired stream and riparian sites representing 11 biomes worldwide. Immobilization rates varied by three orders of magnitude, were greater in rivers than riparian zones, and were strongly correlated to decomposition rates. In rivers, P immobilization rates were controlled by surface water phosphate concentrations, but N immobilization rates were not related to inorganic N. The N:P of immobilized nutrients was tightly constrained to a molar ratio of 10:1 despite wide variation in surface water N:P. Immobilization rates were temperature-dependent in riparian zones but not related to temperature in rivers. However, in rivers nutrient supply ultimately controlled whether microbes could achieve the maximum expected decomposition rate at a given temperature. Collectively, we demonstrated that exogenous nutrient supply and immobilization are critical control points for decomposition of organic matter.
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| 4. |
- Ahmed, Nabeela, et al.
(författare)
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Redefining the role of urban studies Early Career Academics in the post-COVID-19 university
- 2022
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Ingår i: City. - : Informa UK Limited. - 1360-4813 .- 1470-3629. ; 26:4, s. 562-586
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Tidskriftsartikel (refereegranskat)abstract
- We are an international collective of Early Career Academics (ECAs) who met throughout 2020 to explore the implications of COVID-19 on precarious academics. With this intervention, our aims are to voice commonly shared experiences and concerns and to reflect on the extent to which the pandemic offers opportunities to redefine Higher Education and research institutions, in a context of ongoing precarity and funding cuts. Specifically, we explore avenues to build solidarity across institutions and geographies, to ensure that the conduct of urban research, and support offered to ECAs, allows for more inclusivity, diversity, security and equitability.
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| 5. |
- Aro, Rudolf, 1992-
(författare)
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Organofluorine Mass Balance and Per- and Polyfluoroalkyl Substance Analysis of Environmental Samples and Human Blood
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Per- and polyfluoroalkyl substances (PFAS) have been linked to a range of negative health and environmental effects. Regulations limiting and/or banning the use of some of the legacy compounds have been introduced. Consequently, the production and use of PFAS has diversified. The risks posed by these newly introduced PFAS to both the environment and humans may be underestimated if they are not evaluated in current monitoring programs. Organofluorine mass balance analysis has been used in previous studies to estimate the overall exposure to PFAS since naturally occurring organofluorine compounds are rare in nature.In this thesis, the organofluorine mass balance analysis was performed on a variety of samples, from surface water to sewage and human blood. The results indicated the ubiquitous presence of unidentified organofluorines in all environmental compartments and human samples, for example, more than 50 % of extractable organofluorine (EOF) in human samples could not be accounted for by an extended list of target analytes. Until these compounds are identified, it is not possible to assess the risks they pose and it could lead to misguided policy decisions.To tackle the increasingly complex analytical picture and ensure more comprehensive screening, a workflow using EOF as an initial metric to identify pollution hot-spots was proposed. The wider adoption of organofluorine mass balance analysis would also require a better understanding of the analytical instrumentation used for this type of work. Experiments carried out here demonstrated the robustness of combustion ion chromatography in EOF analysis and highlighted areas in need of improvement.While organofluorine mass balance analysis has its drawbacks, the potential health and environmental risks posed by the unidentified organofluorine compounds cannot be underestimated.
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| 6. |
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| 7. |
- Jaiswal, Siddhartha, et al.
(författare)
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Age-Related Clonal Hematopoiesis Associated with Adverse Outcomes.
- 2014
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Ingår i: New England Journal of Medicine. - 0028-4793. ; 371:26, s. 2488-2498
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Tidskriftsartikel (refereegranskat)abstract
- Background The incidence of hematologic cancers increases with age. These cancers are associated with recurrent somatic mutations in specific genes. We hypothesized that such mutations would be detectable in the blood of some persons who are not known to have hematologic disorders. Methods We analyzed whole-exome sequencing data from DNA in the peripheral-blood cells of 17,182 persons who were unselected for hematologic phenotypes. We looked for somatic mutations by identifying previously characterized single-nucleotide variants and small insertions or deletions in 160 genes that are recurrently mutated in hematologic cancers. The presence of mutations was analyzed for an association with hematologic phenotypes, survival, and cardiovascular events. Results Detectable somatic mutations were rare in persons younger than 40 years of age but rose appreciably in frequency with age. Among persons 70 to 79 years of age, 80 to 89 years of age, and 90 to 108 years of age, these clonal mutations were observed in 9.5% (219 of 2300 persons), 11.7% (37 of 317), and 18.4% (19 of 103), respectively. The majority of the variants occurred in three genes: DNMT3A, TET2, and ASXL1. The presence of a somatic mutation was associated with an increase in the risk of hematologic cancer (hazard ratio, 11.1; 95% confidence interval [CI], 3.9 to 32.6), an increase in all-cause mortality (hazard ratio, 1.4; 95% CI, 1.1 to 1.8), and increases in the risks of incident coronary heart disease (hazard ratio, 2.0; 95% CI, 1.2 to 3.4) and ischemic stroke (hazard ratio, 2.6; 95% CI, 1.4 to 4.8). Conclusions Age-related clonal hematopoiesis is a common condition that is associated with increases in the risk of hematologic cancer and in all-cause mortality, with the latter possibly due to an increased risk of cardiovascular disease. (Funded by the National Institutes of Health and others.).
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| 8. |
- Sader, John E., et al.
(författare)
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A virtual instrument to standardise the calibration of atomic force microscope cantilevers
- 2016
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Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 87:9
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Tidskriftsartikel (refereegranskat)abstract
- Atomic force microscope (AFM) users often calibrate the spring constants of cantilevers using functionality built into individual instruments. This calibration is performed without reference to a global standard, hindering the robust comparison of force measurements reported by different laboratories. Here, we describe a virtual instrument (an internet-based initiative) whereby users from all laboratories can instantly and quantitatively compare their calibration measurements to those of others-standardising AFM force measurements-and simultaneously enabling non-invasive calibration of AFM cantilevers of any geometry. This global calibration initiative requires no additional instrumentation or data processing on the part of the user. It utilises a single website where users upload currently available data. A proof-of-principle demonstration of this initiative is presented using measured data from five independent laboratories across three countries, which also allows for an assessment of current calibration.
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| 9. |
- Samplonius, Jelmer M., et al.
(författare)
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Strengthening the evidence base for temperature-mediated phenological asynchrony and its impacts
- 2021
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Ingår i: Nature Ecology and Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 5:2, s. 155-164
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Forskningsöversikt (refereegranskat)abstract
- Climate warming has caused the seasonal timing of many components of ecological food chains to advance. In the context of trophic interactions, the match–mismatch hypothesis postulates that differential shifts can lead to phenological asynchrony with negative impacts for consumers. However, at present there has been no consistent analysis of the links between temperature change, phenological asynchrony and individual-to-population-level impacts across taxa, trophic levels and biomes at a global scale. Here, we propose five criteria that all need to be met to demonstrate that temperature-mediated trophic asynchrony poses a growing risk to consumers. We conduct a literature review of 109 papers studying 129 taxa, and find that all five criteria are assessed for only two taxa, with the majority of taxa only having one or two criteria assessed. Crucially, nearly every study was conducted in Europe or North America, and most studies were on terrestrial secondary consumers. We thus lack a robust evidence base from which to draw general conclusions about the risk that climate-mediated trophic asynchrony may pose to populations worldwide.
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| 10. |
- Wang, Zhanyun, et al.
(författare)
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A Never-Ending Story of Per- and Polyfluoroalkyl Substances (PFASs)?
- 2017
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 51:5, s. 2508-2518
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Tidskriftsartikel (refereegranskat)abstract
- More than 3000 per- and polyfluoroalkyl substances (PFASs) are, or have been, on the global market, yet most research and regulation continues to focus on a limited selection of rather well-known long-chain FASs, particularly perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and their precursors. Continuing to overlook the vast majority of other PFASs is a major concern for society. We provide recommendations for how to proceed with research and cooperation to tackle the vast number of PFASs on the market and in the environment.
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