| 1. |
- Bengtsson, Fia, 1986-, et al.
(författare)
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Environmental drivers of Sphagnum growth in peatlands across the Holarctic region
- 2021
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Ingår i: Journal of Ecology. - : John Wiley & Sons. - 0022-0477 .- 1365-2745. ; 109:1, s. 417-431
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Tidskriftsartikel (refereegranskat)abstract
- The relative importance of global versus local environmental factors for growth and thus carbon uptake of the bryophyte genusSphagnum-the main peat-former and ecosystem engineer in northern peatlands-remains unclear. We measured length growth and net primary production (NPP) of two abundantSphagnumspecies across 99 Holarctic peatlands. We tested the importance of previously proposed abiotic and biotic drivers for peatland carbon uptake (climate, N deposition, water table depth and vascular plant cover) on these two responses. Employing structural equation models (SEMs), we explored both indirect and direct effects of drivers onSphagnumgrowth. Variation in growth was large, but similar within and between peatlands. Length growth showed a stronger response to predictors than NPP. Moreover, the smaller and denserSphagnum fuscumgrowing on hummocks had weaker responses to climatic variation than the larger and looserSphagnum magellanicumgrowing in the wetter conditions. Growth decreased with increasing vascular plant cover within a site. Between sites, precipitation and temperature increased growth forS. magellanicum. The SEMs indicate that indirect effects are important. For example, vascular plant cover increased with a deeper water table, increased nitrogen deposition, precipitation and temperature. These factors also influencedSphagnumgrowth indirectly by affecting moss shoot density. Synthesis. Our results imply that in a warmer climate,S. magellanicumwill increase length growth as long as precipitation is not reduced, whileS. fuscumis more resistant to decreased precipitation, but also less able to take advantage of increased precipitation and temperature. Such species-specific sensitivity to climate may affect competitive outcomes in a changing environment, and potentially the future carbon sink function of peatlands.
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| 2. |
- Farnocchia, Davide, et al.
(författare)
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International Asteroid Warning Network Timing Campaign: 2019 XS
- 2022
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Ingår i: The Planetary Science Journal. - : Institute of Physics Publishing (IOPP). - 2632-3338. ; 3:7
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Tidskriftsartikel (refereegranskat)abstract
- As part of the International Asteroid Warning Network's observational exercises, we conducted a campaign to observe near-Earth asteroid 2019 XS around its close approach to Earth on 2021 November 9. The goal of the campaign was to characterize errors in the observation times reported to the Minor Planet Center, which become an increasingly important consideration as astrometric accuracy improves and more fast-moving asteroids are observed. As part of the exercise, a total of 957 astrometric observations of 2019 XS during the encounter were reported and subsequently were analyzed to obtain the corresponding residuals. While the timing errors are typically smaller than 1 s, the reported times appear to be negatively biased, i.e., they are generally earlier than they should be. We also compared the observer-provided position uncertainty with the cross-track residuals, which are independent of timing errors. A large fraction of the estimated uncertainties appear to be optimistic, especially when <0 2. We compiled individual reports for each observer to help identify and remove the root cause of any possible timing error and improve the uncertainty quantification process. We suggest possible sources of timing errors and describe a simple procedure to derive reliable, conservative position uncertainties.
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| 3. |
- Farnocchia, Davide, et al.
(författare)
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The Second International Asteroid Warning Network Timing Campaign: 2005 LW3
- 2023
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Ingår i: The Planetary Science Journal. - : Institute of Physics (IOP). - 2632-3338. ; 4:11
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Tidskriftsartikel (refereegranskat)abstract
- The Earth close approach of near-Earth asteroid 2005 LW3 on 2022 November 23 represented a good opportunity for a second observing campaign to test the timing accuracy of astrometric observation. With 82 participating stations, the International Asteroid Warning Network collected 1046 observations of 2005 LW3 around the time of the close approach. Compared to the previous timing campaign targeting 2019 XS, some individual observers were able to significantly improve the accuracy of their reported observation times. In particular, U.S. surveys achieved good timing performance. However, no broad, systematic improvement was achieved compared to the previous campaign, with an overall negative bias persisting among the different observers. The calibration of observing times and the mitigation of timing errors should be important future considerations for observers and orbit computers, respectively.
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| 4. |
- Belkin, Liuba, et al.
(författare)
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When Bad is Good (and Good is Bad):Examining the Ironic Antecedents and Consequences of Bad Behavior
- 2023
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Ingår i: Academy of Management Annual Meeting Proceedings. - New York : Academy of Management. - 2151-6561 .- 0065-0668.
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Konferensbidrag (refereegranskat)abstract
- It is a common assumption that organizations should avoid “bad” behaviors, as such behaviors have very few positive outcomes or they are likely motivated by undesirable antecedents. In this symposium, we question this prevailing wisdom, in several ways. We suggest that bad behaviors may both inspire positive outcomes (task performance) and be motivated by seemingly “positive” or innocuous antecedents (gratitude, psychological distance). Additionally, we find that engaging in “bad” behaviors (expressing anger) may have positive relational consequences. Together this symposium explores a series of counterintuitive findings that help explain why bad may be good, and good bad in ways that helps illuminate unexpected behavioral mechanism in workplace relationships.
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| 5. |
- Cao, Ling, et al.
(författare)
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Vulnerability of blue foods to human-induced environmental change
- 2023
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Ingår i: Nature Sustainability. - 2398-9629. ; 6, s. 1186-1198
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Tidskriftsartikel (refereegranskat)abstract
- Global aquatic foods are a key source of nutrition, but how their production is influenced by anthropogenic environmental changes is not well known. The vulnerability of global blue food systems to main environmental stressors and the related spatial impacts across blue food nations are now quantified. Global aquatic or 'blue' foods, essential to over 3.2 billion people, face challenges of maintaining supply in a changing environment while adhering to safety and sustainability standards. Despite the growing concerns over their environmental impacts, limited attention has been paid to how blue food production is influenced by anthropogenic environmental changes. Here we assess the vulnerability of global blue food systems to predominant environmental disturbances and predict the spatial impacts. Over 90% of global blue food production faces substantial risks from environmental change, with the major producers in Asia and the United States facing the greatest threats. Capture fisheries generally demonstrate higher vulnerability than aquaculture in marine environments, while the opposite is true in freshwater environments. While threats to production quantity are widespread across marine and inland systems, food safety risks are concentrated within a few countries. Identifying and supporting mitigation and adaptation measures in response to environmental stressors is particularly important in developing countries in Asia, Latin America and Africa where risks are high and national response capacities are low. These findings lay groundwork for future work to map environmental threats and opportunities, aiding strategic planning and policy development for resilient and sustainable blue food production under changing conditions.
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| 6. |
- Payne, Colton D., et al.
(författare)
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Solution NMR and racemic crystallography provide insights into a novel structural class of cyclic plant peptides
- 2021
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Ingår i: RSC CHEMICAL BIOLOGY. - : Royal Society of Chemistry. - 2633-0679. ; 2:6, s. 1682-1691
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Tidskriftsartikel (refereegranskat)abstract
- Head-to-tail cyclic and disulfide-rich peptides are natural products with applications in drug design. Among these are the PawS-Derived Peptides (PDPs) produced in seeds of the daisy plant family. PDP-23 is a unique member of this class in that it is twice the typical size and adopts two beta-hairpins separated by a hinge region. The beta-hairpins, both stabilised by a single disulfide bond, fold together into a V-shaped tertiary structure creating a hydrophobic core. In water two PDP-23 molecules merge their hydrophobic cores to form a square prism quaternary structure. Here, we synthesised PDP-23 and its enantiomer comprising d-amino acids and achiral glycine, which allowed us to confirm these solution NMR structural data by racemic crystallography. Furthermore, we discovered the related PDP-24. NMR analysis showed that PDP-24 does not form a dimeric structure and it has poor water solubility, but in less polar solvents adopts near identical secondary and tertiary structure to PDP-23. The natural role of these peptides in plants remains enigmatic, as we did not observe any antimicrobial or insecticidal activity. However, the plasticity of these larger PDPs and their ability to change structure under different conditions make them appealing peptide drug scaffolds.
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| 7. |
- Tran, Minh C., et al.
(författare)
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Quantifying heterogeneity in an animal model of acute respiratory distress syndrome, a comparison of inspired sinewave technique to computed tomography
- 2024
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- The inspired sinewave technique (IST) is a non-invasive method to measure lung heterogeneity indices (including both uneven ventilation and perfusion or heterogeneity), which reveal multiple conditions of the lung and lung injury. To evaluate the reproducibility and predicted clinical outcomes of IST heterogeneity values, a comparison with a quantitative lung computed tomography (CT) scan is performed. Six anaesthetised pigs were studied after surfactant depletion by saline-lavage. Paired measurements of lung heterogeneity were then taken with both the IST and CT. Lung heterogeneity measured by the IST was calculated by (a) the ratio of tracer gas outputs measured at oscillation periods of 180 s and 60 s, and (b) by the standard deviation of the modelled log-normal distribution of ventilations and perfusions in the simulation lung. In the CT images, lungs were manually segmented and divided into different regions according to voxel density. A quantitative CT method to calculate the heterogeneity (the Cressoni method) was applied. The IST and CT show good Pearson correlation coefficients in lung heterogeneity measurements (ventilation: 0.71, and perfusion, 0.60, p < 0.001). Within individual animals, the coefficients of determination average ventilation (R2 = 0.53) and perfusion (R2 = 0.68) heterogeneity. Strong concordance rates of 98% in ventilation and 89% when the heterogeneity changes were reported in pairs measured by CT scanning and IST methods. This quantitative method to identify heterogeneity has the potential to replicate CT lung heterogeneity, and to aid individualised care in ARDS.
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