| 1. |
- Boyero, Luz, et al.
(author)
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Riparian plant litter quality increases with latitude
- 2017
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In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
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Journal article (peer-reviewed)abstract
- Plant litter represents a major basal resource in streams, where its decomposition is partly regulated by litter traits. Litter-trait variation may determine the latitudinal gradient in decomposition in streams, which is mainly microbial in the tropics and detritivore-mediated at high latitudes. However, this hypothesis remains untested, as we lack information on large-scale trait variation for riparian litter. Variation cannot easily be inferred from existing leaf-trait databases, since nutrient resorption can cause traits of litter and green leaves to diverge. Here we present the first global-scale assessment of riparian litter quality by determining latitudinal variation (spanning 107 degrees) in litter traits (nutrient concentrations; physical and chemical defences) of 151 species from 24 regions and their relationships with environmental factors and phylogeny. We hypothesized that litter quality would increase with latitude (despite variation within regions) and traits would be correlated to produce 'syndromes' resulting from phylogeny and environmental variation. We found lower litter quality and higher nitrogen: phosphorus ratios in the tropics. Traits were linked but showed no phylogenetic signal, suggesting that syndromes were environmentally determined. Poorer litter quality and greater phosphorus limitation towards the equator may restrict detritivore-mediated decomposition, contributing to the predominance of microbial decomposers in tropical streams.
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| 2. |
- Tiegs, Scott D., et al.
(author)
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Global patterns and drivers of ecosystem functioning in rivers and riparian zones
- 2019
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In: Science Advances. - Washington : American Association of Advancement in Science. - 2375-2548. ; 5:1
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Journal article (peer-reviewed)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. |
- González-Mon, Blanca, 1993-, et al.
(author)
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The importance of cross-scale social relationships for dealing with social-ecological change in agricultural supply chains
- 2024
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In: Journal of Rural Studies. - 0743-0167 .- 1873-1392. ; 105
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Journal article (peer-reviewed)abstract
- Agricultural systems are important for the livelihoods and food security of millions of people. These systems are increasingly interconnected across scales and face challenges in responding to multiple, and coalescing types of environmental, social, and economic change. Most studies on how actors respond to change have focused on farmers and farming communities. In this study, we investigate the connectivity of farming systems to markets, to understand how social relationships across the supply chain influence how actors respond to multiple types of changes. We used a participatory network mapping method to interview actors across a fruit supply chain in the Western Cape, South Africa, that is connected to both global and national markets. We identified droughts, climatic variations, changes related to the COVID-19 pandemic, and other social shifts as the most important changes affecting the production and trade of fruit in this region. We also identified three types of responses to these changes: i) responses concerning the dynamics of trade relationships (e.g., changing or maintaining trade relationships); ii) responses based on changes at the individual level (e.g., changes in farm management); and iii) responses based on social relationships (categorized into four types, namely collaboration, knowledge transfer, financial assistance, and marketing coordination). Within these four types, we found that different types of social networks, that include actors operating at different scales and within and outside of supply chains, mediate responses to change. We also found that networks of collaboration, knowledge exchange and financial assistance show a positive correlation, where actors with an export orientation engage in multiple social relationships that enable responding to changes. However, we found limited participation of local market actors in most of these networks. Further investigating these social networks, and the actors participating in them, is essential to better understand and anticipate how and why agricultural systems respond to multiple types of changes, ultimately influencing their trajectory in an increasingly changing world.
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| 4. |
- González-Mon, Blanca, 1993-, et al.
(author)
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The role of cross-scale social relationships for responding to changes in agricultural systems
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Other publication (other academic/artistic)abstract
- Agricultural systems are important for the livelihoods and food security of millions of people. At the same time, these systems are increasingly interconnected across scales and face the challenge of responding to multiple, and coalescing types of environmental, social, and economic changes. Previous studies investigated such responses to changes placing the focus on farmers and farming communities. In this study, we investigate the connectivity of farming systems to markets with the aim to understand the role of social relationships across the supply chain to influence responses to multiple types of changes. To this end, we conducted interviews with actors across a fruit supply chain in the Western Cape, South Africa, connected to global and national markets, using a participatory network mapping method. The most important changes mentioned affecting the production and trade of fruit in this region included: droughts, climatic changes, changes related to the COVID-19 pandemic, and other social changes. We identified three types of responses to these changes: i) responses concerning the dynamics of trade relationships (e.g., changing or maintaining trade relationships); ii) responses based on changes at the individual level (e.g., changes in farm management); and iii) responses based on social relationships (collaboration, knowledge transfer, financial assistance, and marketing coordination). Building on these four types of social relationships, we found that different social networks mediate responses to changes. These social networks include actors internal and external to the supply chains operating within and across scales. Networks of collaboration, knowledge exchange, and financial assistance show a positive correlation, where actors with an export orientation engage in multiple social relationships that enable responding to changes. However, we found limited participation of local market actors in these networks, besides their role in responses based on marketing coordination. Exploring these social networks and the actors participating in them could be essential to better understand and anticipate how and why agricultural systems respond to multiple types of changes, ultimately influencing their trajectory in an increasingly changing context.
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| 5. |
- Kirkby, Jasper, et al.
(author)
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Ion-induced nucleation of pure biogenic particles
- 2016
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 533:7604, s. 521-526
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Journal article (peer-reviewed)abstract
- Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood(1). Globally, around half of cloud condensation nuclei originate from nucleation of atmospheric vapours(2). It is thought that sulfuric acid is essential to initiate most particle formation in the atmosphere(3,4), and that ions have a relatively minor role(5). Some laboratory studies, however, have reported organic particle formation without the intentional addition of sulfuric acid, although contamination could not be excluded(6,7). Here we present evidence for the formation of aerosol particles from highly oxidized biogenic vapours in the absence of sulfuric acid in a large chamber under atmospheric conditions. The highly oxygenated molecules (HOMs) are produced by ozonolysis of a-pinene. We find that ions from Galactic cosmic rays increase the nucleation rate by one to two orders of magnitude compared with neutral nucleation. Our experimental findings are supported by quantum chemical calculations of the cluster binding energies of representative HOMs. Ion-induced nucleation of pure organic particles constitutes a potentially widespread source of aerosol particles in terrestrial environments with low sulfuric acid pollution.
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| 6. |
- Manzano-Nunez, Ramiro, et al.
(author)
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Outcomes and management approaches of resuscitative endovascular balloon occlusion of the aorta based on the income of countries
- 2020
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In: World Journal of Emergency Surgery. - : Springer Science and Business Media LLC. - 1749-7922. ; 15:57
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Journal article (peer-reviewed)abstract
- © 2020 The Author(s). Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) could provide a survival benefit to severely injured patients as it may improve their initial ability to survive the hemorrhagic shock. Although the evidence supporting the use of REBOA is not conclusive, its use has expanded worldwide. We aim to compare the management approaches and clinical outcomes of trauma patients treated with REBOA according to the countries' income based on the World Bank Country and Lending Groups. Methods: We used data from the AORTA (USA) and the ABOTrauma (multinational) registries. Patients were stratified into two groups: (1) high-income countries (HICs) and (2) low-to-middle income countries (LMICs). Propensity score matching extracted 1:1 matched pairs of subjects who were from an LMIC or a HIC based on age, gender, the presence of pupillary response on admission, impeding hypotension (SBP ≤ 80), trauma mechanism, ISS, the necessity of CPR on arrival, the location of REBOA insertion (emergency room or operating room) and the amount of PRBCs transfused in the first 24 h. Logistic regression (LR) was used to examine the association of LMICs and mortality. Results: A total of 817 trauma patients from 14 countries were included. Blind percutaneous approach and surgical cutdown were the preferred means of femoral cannulation in HICs and LIMCs, respectively. Patients from LMICs had a significantly higher occurrence of MODS and respiratory failure. LR showed no differences in mortality for LMICs when compared to HICs; neither in the non-matched cohort (OR = 0.63; 95% CI: 0.36-1.09; p = 0.1) nor in the matched cohort (OR = 1.45; 95% CI: 0.63-3,33; p = 0.3). Conclusion: There is considerable variation in the management practices of REBOA and the outcomes associated with this intervention between HICs and LMICs. Although we found significant differences in multiorgan and respiratory failure rates, there were no differences in the risk-adjusted odds of mortality between the groups analyzed. Trauma surgeons practicing REBOA around the world should joint efforts to standardize the practice of this endovascular technology worldwide.
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| 7. |
- Pringle, Catherine B., et al.
(author)
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Exploring social processes in transformation : the case of a collaborative water partnership in South Africa
- 2023
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In: Ecosystems and People. - 2639-5908 .- 2639-5916. ; 19:1
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Journal article (peer-reviewed)abstract
- We explore the social processes supporting transformation towards collaborative water governance in the uMngeni catchment, South Africa. Using Holling's adaptive cycle as a heuristic of phases (conservation, release, reorganisation and exploitation) present during transformation of social-ecological systems, we consider the role of learning, power, agency and structure during each phase of the evolution of the uMngeni Ecological Infrastructure Partnership (UEIP). The UEIP is a partnership between government, research institutions, and civil society groups that facilitates broader and more collaborative participation in water management. During the conservation phase, strong control power and institutional structure (denoted by a hierarchical governance mode embodying control and regulation by the State) limited the introduction of new ideas and reinforced single-loop learning. The release phase was triggered by a shock which weakened control power and permitted the introduction of new ideas thereby enabling double-loop learning. The changing conditions gave rise to protean power (defined as results of practices of agile actors coping with uncertainty) which enhanced the agency of key actors who began to mobilise others in a rapid phase of re-organisation. Triple-loop learning was evident in the exploitation phase as new collaborative institutions, that were better able to accommodate innovative ideas, began to emerge. We found the adaptive cycle helpful for delineating phases of change, while the four multi-faceted processes of learning, power, agency and structure proved useful in illuminating dynamics of change. This understanding may help to inform actions to steer transformations towards more sustainable and collaborative water governance in South Africa and elsewhere.
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