1. |
- Tian, Hanqin, et al.
(författare)
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Global soil nitrous oxide emissions since the preindustrial era estimated by an ensemble of terrestrial biosphere models : Magnitude, attribution, and uncertainty
- 2019
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 25:2, s. 640-659
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Tidskriftsartikel (refereegranskat)abstract
- Our understanding and quantification of global soil nitrous oxide (N2O) emissions and the underlying processes remain largely uncertain. Here, we assessed the effects of multiple anthropogenic and natural factors, including nitrogen fertilizer (N) application, atmospheric N deposition, manure N application, land cover change, climate change, and rising atmospheric CO2 concentration, on global soil N2O emissions for the period 1861–2016 using a standard simulation protocol with seven process-based terrestrial biosphere models. Results suggest global soil N2O emissions have increased from 6.3 ± 1.1 Tg N2O-N/year in the preindustrial period (the 1860s) to 10.0 ± 2.0 Tg N2O-N/year in the recent decade (2007–2016). Cropland soil emissions increased from 0.3 Tg N2O-N/year to 3.3 Tg N2O-N/year over the same period, accounting for 82% of the total increase. Regionally, China, South Asia, and Southeast Asia underwent rapid increases in cropland N2O emissions since the 1970s. However, US cropland N2O emissions had been relatively flat in magnitude since the 1980s, and EU cropland N2O emissions appear to have decreased by 14%. Soil N2O emissions from predominantly natural ecosystems accounted for 67% of the global soil emissions in the recent decade but showed only a relatively small increase of 0.7 ± 0.5 Tg N2O-N/year (11%) since the 1860s. In the recent decade, N fertilizer application, N deposition, manure N application, and climate change contributed 54%, 26%, 15%, and 24%, respectively, to the total increase. Rising atmospheric CO2 concentration reduced soil N2O emissions by 10% through the enhanced plant N uptake, while land cover change played a minor role. Our estimation here does not account for indirect emissions from soils and the directed emissions from excreta of grazing livestock. To address uncertainties in estimating regional and global soil N2O emissions, this study recommends several critical strategies for improving the process-based simulations.
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2. |
- Andersson, Henrik, et al.
(författare)
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Assembling surface mounted components on ink-jet printed double sided paper circuit board
- 2014
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 25:9
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Tidskriftsartikel (refereegranskat)abstract
- Printed electronics is a rapidly developing field where many components can already be manufactured on flexible substrates by printing or by other high speed manufacturing methods. However, the functionality of even the most inexpensive microcontroller or other integrated circuit is, at the present time and for the foreseeable future, out of reach by means of fully printed components. Therefore, it is of interest to investigate hybrid printed electronics, where regular electrical components are mounted on flexible substrates to achieve high functionality at a low cost. Moreover, the use of paper as a substrate for printed electronics is of growing interest because it is an environmentally friendly and renewable material and is, additionally, the main material used for many packages in which electronics functionalities could be integrated. One of the challenges for such hybrid printed electronics is the mounting of the components and the interconnection between layers on flexible substrates with printed conductive tracks that should provide as low a resistance as possible while still being able to be used in a high speed manufacturing process. In this article, several conductive adhesives are evaluated as well as soldering for mounting surface mounted components on a paper circuit board with ink-jet printed tracks and, in addition, a double sided Arduino compatible circuit board is manufactured and programmed.
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3. |
- Artigas Soler, María, et al.
(författare)
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Genome-wide association and large-scale follow up identifies 16 new loci influencing lung function.
- 2011
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 43:11, s. 1082-90
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary function measures reflect respiratory health and are used in the diagnosis of chronic obstructive pulmonary disease. We tested genome-wide association with forced expiratory volume in 1 second and the ratio of forced expiratory volume in 1 second to forced vital capacity in 48,201 individuals of European ancestry with follow up of the top associations in up to an additional 46,411 individuals. We identified new regions showing association (combined P < 5 × 10(-8)) with pulmonary function in or near MFAP2, TGFB2, HDAC4, RARB, MECOM (also known as EVI1), SPATA9, ARMC2, NCR3, ZKSCAN3, CDC123, C10orf11, LRP1, CCDC38, MMP15, CFDP1 and KCNE2. Identification of these 16 new loci may provide insight into the molecular mechanisms regulating pulmonary function and into molecular targets for future therapy to alleviate reduced lung function.
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4. |
- Assenhöj, Maria, et al.
(författare)
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Occupational exposure and health surveys at metal additive manufacturing facilities
- 2023
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Ingår i: Frontiers in Public Health. - : FRONTIERS MEDIA SA. - 2296-2565. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Additive manufacturing is a novel state-of-the art technology with significant economic and practical advantages, including the ability to produce complex structures on demand while reducing the need of stocking materials and products. Additive manufacturing is a technology that is here to stay; however, new technologies bring new challenges, not only technical but also from an occupational health and safety perspective. Herein, leading Swedish companies using metal additive manufacturing were studied with the aim of investigating occupational exposure and the utility of chosen exposure- and clinical markers as predictors of potential exposure-related health risks.Methods: Exposure levels were investigated by analysis of airborne dust and metals, alongside particle counting instruments measuring airborne particles in the range of 10 nm-10 mu m to identify dusty work tasks. Health examinations were performed on a total of 48 additive manufacturing workers and 39 controls. All participants completed a questionnaire, underwent spirometry, and blood and urine sampling. A subset underwent further lung function tests.Results: Exposure to inhalable dust and metals were low, but particle counting instruments identified specific work tasks with high particle emissions. Examined health parameters were well within reference values on a group level. However, statistical analysis implied an impact on workers kidney function and possible airway inflammation.Conclusion: The methodology was successful for investigating exposure-related health risks in additive manufacturing. However, most participants have been working <5 years. Therefore, long-term studies are needed before we can conclusively accept or reject the observed effects on health.
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5. |
- Barath, Stefan, 1963-, et al.
(författare)
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Diesel exhaust but not ozone increases fraction of exhaled nitric oxide in a randomized controlled experimental exposure study of healthy human subjects
- 2013
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 12, s. 36-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Fraction of exhaled nitric oxide (FENO) is a promising non-invasive index of airway inflammation that may be used to assess respiratory effects of air pollution. We evaluated FENO as a measure of airway inflammation after controlled exposure to diesel exhaust or ozone. Methods: Healthy volunteers were exposed to either diesel exhaust (particle concentration 300 mu g/m(3)) and filtered air for one hour, or ozone (300 ppb) and filtered air for 75 minutes. FENO was measured in duplicate at expiratory flow rates of 10, 50, 100 and 270 mL/s before, 6 and 24 hours after each exposure. Results: Exposure to diesel exhaust increased FENO at 6 hours compared with air at expiratory flow rates of 10 mL/s (p = 0.01) and at 50 mL/s (p = 0.011), but FENO did not differ significantly at higher flow rates. Increases in FENO following diesel exhaust were attenuated at 24 hours. Ozone did not affect FENO at any flow rate or time point. Conclusions: Exposure to diesel exhaust, but not ozone, increased FENO concentrations in healthy subjects. Differences in the induction of airway inflammation may explain divergent responses to diesel exhaust and ozone, with implications for the use of FENO as an index of exposure to air pollution.
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6. |
- Barath, Stefan, 1963-, et al.
(författare)
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Fraction of exhaled nitric oxide after experimental exposure to diesel exhaust and ozone in man
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: Fraction of exhaled nitric oxide (FENO) is a promising non-invasive index of airways inflammation that may be used to assess the respiratory effects of air pollution, and when sampled at multiple expiratory flow rates can measure inflammation at different levels of the airway tract. We evaluate FENO as a measure of airways inflammation after controlled exposure to dilute diesel exhaust and ozone. Methods: Using a double blind randomised cross-over design, healthy volunteers (26±5 years) were exposed to either diesel exhaust (particle concentration 300 µg/m3) and filtered air for one hour (n=10), or ozone(300 ppb) and filtered air for 75 minutes (n=36). FENO was measured in duplicate at expiratory flow rates of 10, 50, 100 and 270 mL/s before, 6 and 24 hours after the end of each exposure. Results: Exposure to diesel exhaust increased FENO at 6 hours compared to filtered air at expiratory flow rates of 10 mL/s [mean±SEM 60.8 ± 6.0 ppb versus 50.2 ± 5.9 ppb; P=0.01] and at 50 mL/s [18.6 ± 1.6 ppb versus 15.9 ± 1.5 ppb; P=0.011], but concentrations did not differ at higher flow rates. Increases in FENO following diesel exhaust were attenuated at 24 hours and exposure to ozone did not affect FENO at any flow rate or time point. Conclusion: Exposure to diesel exhaust, but not ozone, increases the concentration of FENO in healthy subjects consistent with an inflammatory effect in the central airways. Differences in the induction of airway inflammation may explain divergent responses to diesel exhaust and ozone with implications for the use of FENO as an index of exposure to air pollution.
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7. |
- Bergqvist, Viktoria, et al.
(författare)
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Switching from originator infliximab to the biosimilar CT-P13 in 313 patients with inflammatory bowel disease
- 2018
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Ingår i: Therapeutic Advances in Gastroenterology. - : SAGE Publications. - 1756-283X .- 1756-2848. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: As the patents of originator biologics are expiring, biosimilar versions are becoming available for the treatment of inflammatory bowel disease (IBD). However, published switch studies of the first infliximab biosimilar, CT-P13, have delivered ambiguous results that could be interpreted as showing a trend towards inferior effectiveness in Crohn's disease (CD) compared with ulcerative colitis (UC). The aim of this study was to investigate the effectiveness and safety of switching IBD patients from treatment with Remicade to CT-P13.METHODS: In this prospective observational cohort study, all adult IBD patients on Remicade treatment, at four hospitals, were switched to CT-P13. The primary endpoint was change in clinical disease activity at 2, 6, and 12 months after the switch. Secondary endpoints were subgroup analyses of patients with and without concomitant immunomodulators; changes in biomarkers, quality of life, drug trough levels and anti-drug antibodies (ADAbs); and adverse events.RESULTS: A total of 313 IBD patients were switched (195 CD; 118 UC). There were no significant changes in clinical disease activity, quality of life, biomarkers (except a small but significant increase in albumin in CD) including F-calprotectin, drug trough levels, or proportion of patients in remission. Disease worsening rates were 14.0% for CD and 13.8% for UC; and 2.7% developed ADAbs and 2.2% developed serious adverse events.CONCLUSIONS: This is the largest study of switched IBD patients published to date, and it demonstrates that switching from Remicade to CT-P13 may be done with preserved therapeutic effectiveness and safety in both CD and UC.
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8. |
- Blanke, Jan Hendrik, et al.
(författare)
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Assessing the impact of changes in land-use intensity and climate on simulated trade-offs between crop yield and nitrogen leaching
- 2017
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Ingår i: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809. ; 239, s. 385-398
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a global vegetation model (LPJ-GUESS) is forced with spatial information (Nomenclature of Units for Territorial Statistics (NUTS) 2 level) of land-use intensity change in the form of nitrogen (N) fertilization derived from a model chain which informed the Common Agricultural Policy Regionalized Impact (CAPRI) model. We analysed the combined role of climate change and land-use intensity change for trade-offs between agricultural yield and N leaching in the European Union under two plausible scenarios up until 2040. Furthermore, we assessed both driver importance and uncertainty in future trends based on an alternative land-use intensity dataset derived from an integrated assessment model. LPJ-GUESS simulated an increase in wheat and maize yield but also N leaching for most regions when driven by changes in land-use intensity and climate under RCP 8.5. Under RCP 4.5, N leaching is reduced in 53% of the regions while there is a trade-off in crop productivity. The most important factors influencing yield were CO2 (wheat) and climate (maize), but N application almost equaled these in importance. For N leaching, N application was the most important factor, followed by climate. Therefore, using a constant N application dataset in the absence of future projections has a substantial effect on simulated ecosystem responses, especially for maize yield and N leaching. This study is a first assessment of future N leaching and yield responses based on projections of climate and land-use intensity. It further highlights the importance of accounting for changes in future N applications and land-use intensity in general when evaluating environmental impacts over long time periods.
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9. |
- Blanke, Jan, et al.
(författare)
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Implications of accounting for management intensity on carbon and nitrogen balances of European grasslands
- 2018
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:8
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Tidskriftsartikel (refereegranskat)abstract
- European managed grasslands are amongst the most productive in the world. Besides temperature and the amount and timing of precipitation, grass production is also highly controlled by applications of nitrogen fertilizers and land management to sustain a high productivity. Since management characteristics of pastures vary greatly across Europe, land-use intensity and their projections are critical input variables in earth system modeling when examining and predicting the effects of increasingly intensified agricultural and livestock systems on the environment. In this study, we aim to improve the representation of pastures in the dynamic global vegetation model LPJ-GUESS. This is done by incorporating daily carbon allocation for grasses as a foundation to further implement daily land management routines and land-use intensity data into the model to discriminate between intensively and extensively used regions. We further compare our new simulations with leaf area index observations, reported regional grassland productivity, and simulations conducted with the vegetation model ORCHIDEE-GM. Additionally, we analyze the implications of including pasture fertilization and daily management compared to the standard version of LPJ-GUESS. Our results demonstrate that grassland productivity cannot be adequately captured without including land-use intensity data in form of nitrogen applications. Using this type of information improved spatial patterns of grassland productivity significantly compared to standard LPJ-GUESS. In general, simulations for net primary productivity, net ecosystem carbon balance and nitrogen leaching were considerably increased in the extended version. Finally, the adapted version of LPJ-GUESS, driven with projections of climate and land-use intensity, simulated an increase in potential grassland productivity until 2050 for several agro-climatic regions, most notably for the Mediterranean North, the Mediterranean South, the Atlantic Central and the Atlantic South.
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10. |
- Blomberg, Anders, et al.
(författare)
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Chronic Airflow Limitation, Emphysema and Impaired Diffusing Capacity in Relation to Smoking Habits in a Swedish Middle-Aged Population.
- 2024
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Ingår i: Annals of the American Thoracic Society. - 2329-6933 .- 2325-6621.
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Tidskriftsartikel (refereegranskat)abstract
- RATIONALE: Chronic obstructive pulmonary disease (COPD) includes respiratory symptoms and chronic airflow limitation (CAL). In some cases, emphysema and impaired diffusing capacity for carbon monoxide (DLCO) are present, but characteristics and symptoms vary with smoking exposure.OBJECTIVES: To study the prevalence of CAL, emphysema and impaired DLCO in relation to smoking and respiratory symptoms in a middle-aged population.METHODS: We investigated 28,746 randomly invited individuals (52% women) aged 50-64 years across six Swedish sites. We performed spirometry, DLCO, high-resolution computed tomography (HRCT) and asked for smoking habits and respiratory symptoms. CAL was defined as post-bronchodilator forced expiratory volume in 1 second divided by forced expiratory volume (FEV1/FVC)<0.7.RESULTS: The overall prevalence was for CAL 8.8%, for impaired DLCO (DLCOCONCLUSIONS: In this large population-based study of middle-aged people, CAL and impaired DLCO were associated with common respiratory symptoms. Self-reported asthma was not associated with CAL in never-smokers. Our findings suggest that CAL in never-smokers signifies a separate clinical phenotype that may be monitored and, possibly, treated differently from smoking-related COPD. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
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11. |
- Bodin, Per, et al.
(författare)
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Optimizing cropland cover for stable food production in Sub-Saharan Africa using simulated yield and Modern Portfolio Theory
- 2014
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Ingår i: Earth System Dynamics Discussion. - : Copernicus GmbH. - 2190-4995. ; 5, s. 1571-1606
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Food security can be defined as stable access to food of good nutritional quality. In Sub Saharan Africa access to food is strongly linked to local food production and the capacity to generate enough calories to sustain the local population. Therefore it is important in these regions to generate not only sufficiently high yields but also to reduce interannual variability in food production. Traditionally, climate impact simulation studies have focused on factors that underlie maximum productivity ignoring the variability in yield. By using Modern Portfolio Theory, a method stemming from economics, we here calculate optimum current and future crop selection that maintain current yield while minimizing variance, vs. maintaining variance while maximizing yield. Based on simulated yield using the LPJ-GUESS dynamic vegetation model, the results show that current cropland distribution for many crops is close to these optimum distributions. Even so, the optimizations displayed substantial potential to either increase food production and/or to decrease its variance regionally. Our approach can also be seen as a method to create future scenarios for the sown areas of crops in regions where local food production is important for food security.
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12. |
- Camargo-Alvarez, Hector, et al.
(författare)
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Modelling crop yield and harvest index : the role of carbon assimilation and allocation parameters
- 2023
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Ingår i: Modeling Earth Systems and Environment. - : Springer Science and Business Media LLC. - 2363-6203 .- 2363-6211. ; 9:2, s. 2617-2635
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Tidskriftsartikel (refereegranskat)abstract
- Crop yield improvement during the last decades has relied on increasing the ratio of the economic organ to the total aboveground biomass, known as the harvest index (HI). In most crop models, HI is set as a parameter; this empirical approach does not consider that HI not only depends on plant genotype, but is also affected by the environment. An alternative is to simulate allocation mechanistically, as in the LPJ-GUESS crop model, which simulates HI based on daily growing conditions and the crop development stage. Simulated HI is critical for agricultural research due to its economic importance, but it also can validate the robust representation of production processes. However, there is a challenge to constrain parameter values globally for the allocation processes. Therefore, this paper aims to evaluate the sensitivity of yield and HI of wheat and maize simulated with LPJ-GUESS to eight production allocation-related parameters and identify the most suitable parameter values for global simulations. The nitrogen demand reduction after anthesis, the minimum leaf carbon to nitrogen ratio (C:N) and the range of leaf C:N strongly affected carbon assimilation and yield, while the retranslocation of labile stem carbon to grains and the retranslocation rate of nitrogen and carbon from vegetative organs to grains after anthesis mainly influenced HI. A global database of observed HI for both crops was compiled for reference to constrain simulations before calibrating parameters for yield against reference data. Two high- and low-yielding maize cultivars emerged from the calibration, whilst spring and winter cultivars were found appropriate for wheat. The calibrated version of LPJ-GUESS improved the simulation of yield and HI at the global scale for both crops, providing a basis for future studies exploring crop production under different climate and management scenarios.
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13. |
- Deryng, Delphine, et al.
(författare)
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Regional disparities in the beneficial effects of rising CO2 concentrations on crop water productivity
- 2016
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Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 6:8, s. 786-790
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Tidskriftsartikel (refereegranskat)abstract
- Rising atmospheric CO2 concentrations ([CO2 ]) are expected to enhance photosynthesis and reduce crop water use. However, there is high uncertainty about the global implications of these effects for future crop production and agricultural water requirements under climate change. Here we combine results from networks of field experiments and global crop models to present a spatially explicit global perspective on crop water productivity (CWP, the ratio of crop yield to evapotranspiration) for wheat, maize, rice and soybean under elevated [CO2 ] and associated climate change projected for a high-end greenhouse gas emissions scenario. We find CO2 effects increase global CWP by 10[0;47]%-27[7;37]% (median[interquartile range] across the model ensemble) by the 2080s depending on crop types, with particularly large increases in arid regions (by up to 48[25;56]% for rainfed wheat). If realized in the fields, the effects of elevated [CO2 ] could considerably mitigate global yield losses whilst reducing agricultural consumptive water use (4-17%). We identify regional disparities driven by differences in growing conditions across agro-ecosystems that could have implications for increasing food production without compromising water security. Finally, our results demonstrate the need to expand field experiments and encourage greater consistency in modelling the effects of rising [CO2 ] across crop and hydrological modelling communities.
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14. |
- Eckes-Shephard, Annemarie, et al.
(författare)
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State-of-the-art capabilities in LPJ-GUESS
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- LPJ-GUESS is an advanced DGVM including detailed forest demography and management, croplands, wetlands, specialised arctic processes, emissions of nonCO2 GHGs and a highly flexible land-use change scheme which tracks transitions between different land-uses. It is the vegetation component of the EC-Earth CMIP6 ESM, the RCA-GUESS regional ESM, and also has a European mode operating at tree species level.
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15. |
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16. |
- Ekström, Magnus Pär, et al.
(författare)
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The association of body mass index, weight gain and central obesity with activity-related breathlessness : the Swedish Cardiopulmonary Bioimage Study
- 2019
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Ingår i: Thorax. - : BMJ Publishing Group Ltd. - 0040-6376 .- 1468-3296. ; 74:10, s. 958-964
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Breathlessness is common in the population, especially in women and associated with adverse health outcomes. Obesity (body mass index (BMI) >30 kg/m(2)) is rapidly increasing globally and its impact on breathlessness is unclear.Methods: This population-based study aimed primarily to evaluate the association of current BMI and self-reported change in BMI since age 20 with breathlessness (modified Research Council score >= 1) in the middle-aged population. Secondary aims were to evaluate factors that contribute to breathlessness in obesity, including the interaction with spirometric lung volume and sex.Results: We included 13 437 individuals; mean age 57.5 years; 52.5% women; mean BMI 26.8 (SD 4.3); mean BMI increase since age 20 was 5.0 kg/m(2); and 1283 (9.6%) reported breathlessness. Obesity was strongly associated with increased breathlessness, OR 3.54 (95% CI, 3.03 to 4.13) independent of age, sex, smoking, airflow obstruction, exercise level and the presence of comorbidities. The association between BMI and breathlessness was modified by lung volume; the increase in breathlessness prevalence with higher BMI was steeper for individuals with lower forced vital capacity (FVC). The higher breathlessness prevalence in obese women than men (27.4% vs 12.5%; p<0.001) was related to their lower FVC. Irrespective of current BMI and confounders, individuals who had increased in BMI since age 20 had more breathlessness.Conclusion: Breathlessness is independently associated with obesity and with weight gain in adult life, and the association is stronger for individuals with lower lung volumes.
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17. |
- Engström, Kerstin, et al.
(författare)
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Assessing uncertainties in global cropland futures using a conditional probabilistic modelling framework
- 2016
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Ingår i: Earth System Dynamics. - : Copernicus GmbH. - 2190-4979 .- 2190-4987. ; 7:4, s. 893-915
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Tidskriftsartikel (refereegranskat)abstract
- We present a modelling framework to simulate probabilistic futures of global cropland areas that are conditional on the SSP (shared socio-economic pathway) scenarios. Simulations are based on the Parsimonious Land Use Model (PLUM) linked with the global dynamic vegetation model LPJ-GUESS (Lund-Potsdam-Jena General Ecosystem Simulator) using socio-economic data from the SSPs and climate data from the RCPs (representative concentration pathways). The simulated range of global cropland is 893-2380 Mha in 2100 (± 1 standard deviation), with the main uncertainties arising from differences in the socio-economic conditions prescribed by the SSP scenarios and the assumptions that underpin the translation of qualitative SSP storylines into quantitative model input parameters. Uncertainties in the assumptions for population growth, technological change and cropland degradation were found to be the most important for global cropland, while uncertainty in food consumption had less influence on the results. The uncertainties arising from climate variability and the differences between climate change scenarios do not strongly affect the range of global cropland futures. Some overlap occurred across all of the conditional probabilistic futures, except for those based on SSP3. We conclude that completely different socio-economic and climate change futures, although sharing low to medium population development, can result in very similar cropland areas on the aggregated global scale.
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18. |
- Engström, Kerstin, et al.
(författare)
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Impacts of climate mitigation strategies in the energy sector on global land use and carbon balance
- 2017
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Ingår i: Earth System Dynamics. - : Copernicus GmbH. - 2190-4979 .- 2190-4987. ; 8:3, s. 773-799
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Tidskriftsartikel (refereegranskat)abstract
- Reducing greenhouse gas emissions to limit damage to the global economy climate-change-induced and secure the livelihoods of future generations requires ambitious mitigation strategies. The introduction of a global carbon tax on fossil fuels is tested here as a mitigation strategy to reduce atmospheric CO2 concentrations and radiative forcing. Taxation of fossil fuels potentially leads to changed composition of energy sources, including a larger relative contribution from bioenergy. Further, the introduction of a mitigation strategy reduces climate-change-induced damage to the global economy, and thus can indirectly affect consumption patterns and investments in agricultural technologies and yield enhancement. Here we assess the implications of changes in bioenergy demand as well as the indirectly caused changes in consumption and crop yields for global and national cropland area and terrestrial biosphere carbon balance. We apply a novel integrated assessment modelling framework, combining three previously published models (a climate-economy model, a socio-economic land use model and an ecosystem model). We develop reference and mitigation scenarios based on the narratives and key elements of the shared socio-economic pathways (SSPs). Taking emissions from the land use sector into account, we find that the introduction of a global carbon tax on the fossil fuel sector is an effective mitigation strategy only for scenarios with low population development and strong sustainability criteria (SSP1 Taking the green road). For scenarios with high population growth, low technological development and bioenergy production the high demand for cropland causes the terrestrial biosphere to switch from being a carbon sink to a source by the end of the 21st century.
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19. |
- Folberth, Christian, et al.
(författare)
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Parameterization-induced uncertainties and impacts of crop management harmonization in a global gridded crop model ensemble
- 2019
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- Global gridded crop models (GGCMs) combine agronomic or plant growth models with gridded spatial input data to estimate spatially explicit crop yields and agricultural externalities at the global scale. Differences in GGCM outputs arise from the use of different biophysical models, setups, and input data. GGCM ensembles are frequently employed to bracket uncertainties in impact studies without investigating the causes of divergence in outputs. This study explores differences in maize yield estimates from five GGCMs based on the public domain field-scale model Environmental Policy Integrated Climate (EPIC) that participate in the AgMIP Global Gridded Crop Model Intercomparison initiative. Albeit using the same crop model, the GGCMs differ in model version, input data, management assumptions, parameterization, and selection of subroutines affecting crop yield estimates via cultivar distributions, soil attributes, and hydrology among others. The analyses reveal inter-annual yield variability and absolute yield levels in the EPIC-based GGCMs to be highly sensitive to soil parameterization and crop management. All GGCMs show an intermediate performance in reproducing reported yields with a higher skill if a static soil profile is assumed or sufficient plant nutrients are supplied. An in-depth comparison of setup domains for two EPIC-based GGCMs shows that GGCM performance and plant stress responses depend substantially on soil parameters and soil process parameterization, i.e. hydrology and nutrient turnover, indicating that these often neglected domains deserve more scrutiny. For agricultural impact assessments, employing a GGCM ensemble with its widely varying assumptions in setups appears the best solution for coping with uncertainties from lack of comprehensive global data on crop management, cultivar distributions and coefficients for agro-environmental processes. However, the underlying assumptions require systematic specifications to cover representative agricultural systems and environmental conditions. Furthermore, the interlinkage of parameter sensitivity from various domains such as soil parameters, nutrient turnover coefficients, and cultivar specifications highlights that global sensitivity analyses and calibration need to be performed in an integrated manner to avoid bias resulting from disregarded core model domains. Finally, relating evaluations of the EPIC-based GGCMs to a wider ensemble based on individual core models shows that structural differences outweigh in general differences in configurations of GGCMs based on the same model, and that the ensemble mean gains higher skill from the inclusion of structurally different GGCMs. Although the members of the wider ensemble herein do not consider crop-soil-management interactions, their sensitivity to nutrient supply indicates that findings for the EPIC-based sub-ensemble will likely become relevant for other GGCMs with the progressing inclusion of such processes.
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20. |
- Franke, James A, et al.
(författare)
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Agricultural breadbaskets shift poleward given adaptive farmer behavior under climate change
- 2022
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 28:1, s. 167-181
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Tidskriftsartikel (refereegranskat)abstract
- Modern food production is spatially concentrated in global "breadbaskets". A major unresolved question is whether these peak production regions will shift poleward as the climate warms, allowing some recovery of potential climaterelated losses. While agricultural impacts studies to date have focused on currently cultivated land, the Global Gridded Crop Model Intercomparison Project (GGCMI) Phase 2 experiment allows us to assess changes in both yields and the location of peak productivity regions under warming. We examine crop responses under projected end-of-century warming using 7 process-based models simulating 5 major crops (maize, rice, soybeans, and spring and winter wheat) with a variety of adaptation strategies. We find that in no-adaptation cases, when planting date and cultivar choices are held fixed, regions of peak production remain stationary and yield losses can be severe, since growing seasons contract strongly with warming. When adaptations in management practices are allowed (cultivars that retain growing season length under warming and modified planting dates), peak productivity zones shift poleward and yield losses are largely recovered. While most growing-zone shifts are ultimately limited by geography, breadbaskets studied here move poleward over 600 km on average by end of the century under RCP8.5. These results suggest that agricultural impacts assessments can be strongly biased if restricted in spatial area or in the scope of adaptive behavior considered. Accurate evaluation of food security under climate change requires global modeling and careful treatment of adaptation strategies.
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21. |
- Franke, James A., et al.
(författare)
-
The GGCMI Phase 2 emulators : Global gridded crop model responses to changes in CO2, temperature, water, and nitrogen (version 1.0)
- 2020
-
Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 13:9, s. 3995-4018
-
Tidskriftsartikel (refereegranskat)abstract
- Statistical emulation allows combining advantageous features of statistical and process-based crop models for understanding the effects of future climate changes on crop yields. We describe here the development of emulators for nine process-based crop models and five crops using output from the Global Gridded Model Intercomparison Project (GGCMI) Phase 2. The GGCMI Phase 2 experiment is designed with the explicit goal of producing a structured training dataset for emulator development that samples across four dimensions relevant to crop yields: Atmospheric carbon dioxide (CO2) concentrations, temperature, water supply, and nitrogen inputs (CTWN). Simulations are run under two different adaptation assumptions: That growing seasons shorten in warmer climates, and that cultivar choice allows growing seasons to remain fixed. The dataset allows emulating the climatological-mean yield response of all models with a simple polynomial in mean growing-season values. Climatological-mean yields are a central metric in climate change impact analysis; we show here that they can be captured without relying on interannual variations. In general, emulation errors are negligible relative to differences across crop models or even across climate model scenarios; errors become significant only in some marginal lands where crops are not currently grown. We demonstrate that the resulting GGCMI emulators can reproduce yields under realistic future climate simulations, even though the GGCMI Phase 2 dataset is constructed with uniform CTWN offsets, suggesting that the effects of changes in temperature and precipitation distributions are small relative to those of changing means. The resulting emulators therefore capture relevant crop model responses in a lightweight, computationally tractable form, providing a tool that can facilitate model comparison, diagnosis of interacting factors affecting yields, and integrated assessment of climate impacts.
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22. |
- Franke, James A., et al.
(författare)
-
The GGCMI Phase 2 experiment : Global gridded crop model simulations under uniform changes in CO2, temperature, water, and nitrogen levels (protocol version 1.0)
- 2020
-
Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 13:5, s. 2315-2336
-
Tidskriftsartikel (refereegranskat)abstract
- Concerns about food security under climate change motivate efforts to better understand future changes in crop yields. Process-based crop models, which represent plant physiological and soil processes, are necessary tools for this purpose since they allow representing future climate and management conditions not sampled in the historical record and new locations to which cultivation may shift. However, process-based crop models differ in many critical details, and their responses to different interacting factors remain only poorly understood. The Global Gridded Crop Model Intercomparison (GGCMI) Phase 2 experiment, an activity of the Agricultural Model Intercomparison and Improvement Project (AgMIP), is designed to provide a systematic parameter sweep focused on climate change factors and their interaction with overall soil fertility, to allow both evaluating model behavior and emulating model responses in impact assessment tools. In this paper we describe the GGCMI Phase 2 experimental protocol and its simulation data archive. A total of 12 crop models simulate five crops with systematic uniform perturbations of historical climate, varying CO2, temperature, water supply, and applied nitrogen ("CTWN") for rainfed and irrigated agriculture, and a second set of simulations represents a type of adaptation by allowing the adjustment of growing season length. We present some crop yield results to illustrate general characteristics of the simulations and potential uses of the GGCMI Phase 2 archive. For example, in cases without adaptation, modeled yields show robust decreases to warmer temperatures in almost all regions, with a nonlinear dependence that means yields in warmer baseline locations have greater temperature sensitivity. Inter-model uncertainty is qualitatively similar across all the four input dimensions but is largest in high-latitude regions where crops may be grown in the future.
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23. |
- Franzén, Stefan, et al.
(författare)
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Aortic valve replacement with pericardial valves in patients with small aortic roots. Clinical results in a consecutive series of patients receiving 19 and 21 mm prostheses
- 2001
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 35:2, s. 114-118
-
Tidskriftsartikel (refereegranskat)abstract
- Objective - To determine how second generation pericardial valves perform in patients with small aortic roots. Design - Ninety patients who underwent isolated aortic valve replacement (AVR) with 19 or 21 mm Mitroflow« or Carpentier-Edwards (Perimount«) valves between 1989 and 1996 were studied. Mean age was 78 years. Concomitant coronary bypass surgery was performed in 41%. Results - Thirty-day mortality was 5.6%. Ninety-seven percent had acceptable transprosthetic mean pressure gradients (25 mmHg or less) 1 week after surgery. Follow-up was 100% complete and 76% of the patients were alive after a mean of 5 years. There was no structural valve failure or valve thrombosis. One patient required reoperation for perivalvular leak. Four patients had transient ischemic attacks and seven had strokes. These figures are, however, within the expected range for the age. Conclusion - Second generation pericardial valves perform well in elderly patients with small aortic roots. Postoperative hemodynamics are acceptable, valve durability of up to 8 years adequate, and the clinical results good, considering the age of the patients.
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24. |
- Frieler, Katja, et al.
(författare)
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Understanding the weather signal in national crop-yield variability
- 2017
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Ingår i: Earth's Future. - 2328-4277. ; 5:6, s. 605-616
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Tidskriftsartikel (refereegranskat)abstract
- Year-to-year variations in crop yields can have major impacts on the livelihoods of subsistence farmers and may trigger significant global price fluctuations, with severe consequences for people in developing countries. Fluctuations can be induced by weather conditions, management decisions, weeds, diseases, and pests. Although an explicit quantification and deeper understanding of weather-induced crop-yield variability is essential for adaptation strategies, so far it has only been addressed by empirical models. Here, we provide conservative estimates of the fraction of reported national yield variabilities that can be attributed to weather by state-of-the-art, process-based crop model simulations. We find that observed weather variations can explain more than 50% of the variability in wheat yields in Australia, Canada, Spain, Hungary, and Romania. For maize, weather sensitivities exceed 50% in seven countries, including the United States. The explained variance exceeds 50% for rice in Japan and South Korea and for soy in Argentina. Avoiding water stress by simulating yields assuming full irrigation shows that water limitation is a major driver of the observed variations in most of these countries. Identifying the mechanisms leading to crop-yield fluctuations is not only fundamental for dampening fluctuations, but is also important in the context of the debate on the attribution of loss and damage to climate change. Since process-based crop models not only account for weather influences on crop yields, but also provide options to represent human-management measures, they could become essential tools for differentiating these drivers, and for exploring options to reduce future yield fluctuations.
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25. |
- Guan, Qi, et al.
(författare)
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Long-term changes of nitrogen leaching and the contributions of terrestrial nutrient sources to lake eutrophication dynamics on the Yangtze Plain of China
- 2023
-
Ingår i: Biogeosciences. - 1726-4170. ; 20:8, s. 1635-1648
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Tidskriftsartikel (refereegranskat)abstract
- Over the past half-century, drastically increased chemical fertilizers have entered agricultural ecosystems to promote crop production on the Yangtze Plain, potentially enhancing agricultural nutrient sources for eutrophication in freshwater ecosystems. However, long-term trends of nitrogen dynamics in terrestrial ecosystems and their impacts on eutrophication changes in this region remain poorly studied. Using a process-based ecosystem model, we investigated the temporal and spatial patterns of nitrogen use efficiency (NUE) and nitrogen leaching on the Yangtze Plain from 1979-2018. The agricultural NUE for the Yangtze Plain significantly decreased from 50g€¯% in 1979 to 25g€¯% in 2018, with the largest decline of NUE in soybean, rice, and rapeseed. Simultaneously, the leached nitrogen from cropland and natural land increased, with annual rates of 4.5 and 0.22g€¯kgg€¯Ng€¯ha-1g€¯yr-2, respectively, leading to an overall increase of nitrogen inputs to the 50 large lakes. We further examined the correlations between terrestrial nutrient sources (i.e., the leached nitrogen, total phosphorus sources, and industrial wastewater discharge) and the satellite-observed probability of eutrophication occurrence (PEO) at an annual scale and showed that PEO was positively correlated with the changes in terrestrial nutrient sources for most lakes. Agricultural nitrogen and phosphorus sources were found to explain the PEO trends in lakes in the western and central part of the Yangtze Plain, and industrial wastewater discharge was associated with the PEO trends in eastern lakes. Our results revealed the importance of terrestrial nutrient sources for long-term changes in eutrophic status over the 50 lakes of the Yangtze Plain. This calls for region-specific sustainable nutrient management (i.e., nitrogen and phosphorus applications in agriculture and industry) to improve the water quality of lake ecosystems.
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26. |
- Gustafson, Adrian, et al.
(författare)
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Nitrogen restricts future sub-Arctic treeline advance in an individual-based dynamic vegetation model
- 2021
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 18, s. 6329-6347
-
Tidskriftsartikel (refereegranskat)abstract
- Arctic environmental change induces shifts in high-latitude plant community composition and stature with implications for Arctic carbon cycling and energy exchange. Two major components of change in high-latitude ecosystems are the advancement of trees into tundra and the increased abundance and size of shrubs. How future changes in key climatic and environmental drivers will affect distributions of major ecosystem types is an active area of research. Dynamic vegetation models (DVMs) offer a way to investigate multiple and interacting drivers of vegetation distribution and ecosystem function. We employed the LPJ-GUESS tree-individual-based DVM over the Torneträsk area, a sub-Arctic landscape in northern Sweden. Using a highly resolved climate dataset to downscale CMIP5 climate data from three global climate models and two 21st-century future scenarios (RCP2.6 and RCP8.5), we investigated future impacts of climate change on these ecosystems. We also performed model experiments where we factorially varied drivers (climate, nitrogen deposition and [CO2]) to disentangle the effects of each on ecosystem properties and functions. Our model predicted that treelines could advance by between 45 and 195 elevational metres by 2100, depending on the scenario. Temperature was a strong driver of vegetation change, with nitrogen availability identified as an important modulator of treeline advance. While increased CO2 fertilisation drove productivity increases, it did not result in range shifts of trees. Treeline advance was realistically simulated without any temperature dependence on growth, but biomass was overestimated. Our finding that nitrogen cycling could modulate treeline advance underlines the importance of representing plant-soil interactions in models to project future Arctic vegetation change.
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27. |
- Gustafsson, Anna, et al.
(författare)
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Antisecretory factor in breastmilk is associated with reduced incidence of sepsis in preterm infants
- 2023
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Ingår i: Pediatric Research. - 0031-3998 .- 1530-0447. ; 95:3, s. 762-69
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Tidskriftsartikel (refereegranskat)abstract
- Background: Antisecretory Factor (AF) is a protein present in breastmilk that regulates inflammatory processes. We aimed to investigate the level of AF in mothers’ own milk (MOM) in relation to sepsis and other neonatal morbidities in preterm infants. Methods: Samples of breastmilk and infant plasma were collected at 1, 4, and 12 weeks after birth from 38 mothers and their 49 infants born before 30 weeks gestation. AF-compleasome in MOM was determined by a sandwich enzyme-linked immunosorbent assay (ELISA) and inflammatory markers in infant plasma by a panel of 92 inflammatory proteins. Neonatal treatments and outcomes were recorded. Results: The level of AF in MOM week 1 was lower for infants with later sepsis compared to no sepsis (p = 0.005). Corrected for nutritional intake of MOM, higher levels of AF decreased the risk for sepsis, OR 0.24. AF in MOM week 1 was negatively correlated to inflammatory proteins in infant plasma week 4, markedly IL-8, which was also associated with infant sepsis. Overall, higher AF levels in MOM was associated with fewer major morbidities of prematurity. Conclusion: Mother’s milk containing high levels of antisecretory factor is associated with reduced risk for sepsis and inflammation in preterm infants. Impact: High level of antisecretory factor (AF) in mothers’ own milk is associated with less risk for later sepsis in preterm infants.Receiving mothers’ milk with low AF levels during the first week after birth is correlated with more inflammatory proteins in infant’s plasma 2–4 weeks later.Human breastmilk has anti-inflammatory properties, and antisecretory factor in mothers’ own milk is a component of potential importance for infants born preterm.The findings suggest that food supplementation with AF to mothers of preterm infants to increase AF-levels in breastmilk may be a means to decrease the risk of inflammatory morbidities of prematurity.
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28. |
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29. |
- Jansen, Willemijn J, et al.
(författare)
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Prevalence Estimates of Amyloid Abnormality Across the Alzheimer Disease Clinical Spectrum.
- 2022
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Ingår i: JAMA neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 79:3, s. 228-243
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Tidskriftsartikel (refereegranskat)abstract
- One characteristic histopathological event in Alzheimer disease (AD) is cerebral amyloid aggregation, which can be detected by biomarkers in cerebrospinal fluid (CSF) and on positron emission tomography (PET) scans. Prevalence estimates of amyloid pathology are important for health care planning and clinical trial design.To estimate the prevalence of amyloid abnormality in persons with normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia and to examine the potential implications of cutoff methods, biomarker modality (CSF or PET), age, sex, APOE genotype, educational level, geographical region, and dementia severity for these estimates.This cross-sectional, individual-participant pooled study included participants from 85 Amyloid Biomarker Study cohorts. Data collection was performed from January 1, 2013, to December 31, 2020. Participants had normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia. Normal cognition and subjective cognitive decline were defined by normal scores on cognitive tests, with the presence of cognitive complaints defining subjective cognitive decline. Mild cognitive impairment and clinical AD dementia were diagnosed according to published criteria.Alzheimer disease biomarkers detected on PET or in CSF.Amyloid measurements were dichotomized as normal or abnormal using cohort-provided cutoffs for CSF or PET or by visual reading for PET. Adjusted data-driven cutoffs for abnormal amyloid were calculated using gaussian mixture modeling. Prevalence of amyloid abnormality was estimated according to age, sex, cognitive status, biomarker modality, APOE carrier status, educational level, geographical location, and dementia severity using generalized estimating equations.Among the 19097 participants (mean [SD] age, 69.1 [9.8] years; 10148 women [53.1%]) included, 10139 (53.1%) underwent an amyloid PET scan and 8958 (46.9%) had an amyloid CSF measurement. Using cohort-provided cutoffs, amyloid abnormality prevalences were similar to 2015 estimates for individuals without dementia and were similar across PET- and CSF-based estimates (24%; 95% CI, 21%-28%) in participants with normal cognition, 27% (95% CI, 21%-33%) in participants with subjective cognitive decline, and 51% (95% CI, 46%-56%) in participants with mild cognitive impairment, whereas for clinical AD dementia the estimates were higher for PET than CSF (87% vs 79%; mean difference, 8%; 95% CI, 0%-16%; P=.04). Gaussian mixture modeling-based cutoffs for amyloid measures on PET scans were similar to cohort-provided cutoffs and were not adjusted. Adjusted CSF cutoffs resulted in a 10% higher amyloid abnormality prevalence than PET-based estimates in persons with normal cognition (mean difference, 9%; 95% CI, 3%-15%; P=.004), subjective cognitive decline (9%; 95% CI, 3%-15%; P=.005), and mild cognitive impairment (10%; 95% CI, 3%-17%; P=.004), whereas the estimates were comparable in persons with clinical AD dementia (mean difference, 4%; 95% CI, -2% to 9%; P=.18).This study found that CSF-based estimates using adjusted data-driven cutoffs were up to 10% higher than PET-based estimates in people without dementia, whereas the results were similar among people with dementia. This finding suggests that preclinical and prodromal AD may be more prevalent than previously estimated, which has important implications for clinical trial recruitment strategies and health care planning policies.
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30. |
- Johansson, Emma, et al.
(författare)
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Foreign demand for agricultural commodities drives virtual carbon exports from Cambodia
- 2020
-
Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 15:6
-
Tidskriftsartikel (refereegranskat)abstract
- Rapid deforestation is a major sustainability challenge, partly as the loss of carbon sinks exacerbates global climate change. In Cambodia, more than 13% of the total land area has been contracted out to foreign and domestic agribusinesses in the form of economic land concessions, causing rapid large-scale land use change and deforestation. Additionally, the distant drivers of local and global environmental change often remain invisible. Here, we identify hotspots of carbon loss between 1987-2017 using the dynamic global vegetation model LPJ-GUESS and by comparing past and present land use and land cover. We also link global consumption and production patterns to their environmental effects in Cambodia by mapping the countries to which land-use embedded carbon are exported. We find that natural forests have decreased from 54%-21% between 1987 and 2017, mainly for the expansion of farmland and orchards, translating into 300 million tons of carbon lost, with loss rates over twice as high within economic land concessions. China is the largest importer of embedded carbon, mainly for rubber and sugarcane from Chinese agribusinesses. Cambodian investors have also negatively affected carbon pools through export-oriented products like rubber. The combined understanding of environmental change and trade flows makes it possible to identify distant drivers of deforestation, which is important for crafting more environmentally and socially responsible policies on national and transnational scales.
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31. |
- Krause, Andreas, et al.
(författare)
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Global consequences of afforestation and bioenergy cultivation on ecosystem service indicators
- 2017
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 14:21, s. 4829-4850
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Tidskriftsartikel (refereegranskat)abstract
- Land management for carbon storage is discussed as being indispensable for climate change mitigation because of its large potential to remove carbon dioxide from the atmosphere, and to avoid further emissions from deforestation. However, the acceptance and feasibility of land-based mitigation projects depends on potential side effects on other important ecosystem functions and their services. Here, we use projections of future land use and land cover for different land-based mitigation options from two land-use models (IMAGE and MAgPIE) and evaluate their effects with a global dynamic vegetation model (LPJ-GUESS). In the landuse models, carbon removal was achieved either via growth of bioenergy crops combined with carbon capture and storage, via avoided deforestation and afforestation, or via a combination of both. We compare these scenarios to a reference scenario without land-based mitigation and analyse the LPJ-GUESS simulations with the aim of assessing synergies and trade-offs across a range of ecosystem service indicators: Carbon storage, surface albedo, evapotranspiration, water runoff, crop production, nitrogen loss, and emissions of biogenic volatile organic compounds. In our mitigation simulations cumulative carbon storage by year 2099 ranged between 55 and 89 GtC. Other ecosystem service indicators were influenced heterogeneously both positively and negatively, with large variability across regions and land-use scenarios. Avoided deforestation and afforestation led to an increase in evapotranspiration and enhanced emissions of biogenic volatile organic compounds, and to a decrease in albedo, runoff, and nitrogen loss. Crop production could also decrease in the afforestation scenarios as a result of reduced crop area, especially for MAgPIE land-use patterns, if assumed increases in crop yields cannot be realized. Bioenergy-based climate change mitigation was projected to affect less area globally than in the forest expansion scenarios, and resulted in less pronounced changes in most ecosystem service indicators than forest-based mitigation, but included a possible decrease in nitrogen loss, crop production, and biogenic volatile organic compounds emissions.
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32. |
- Krause, Andreas, et al.
(författare)
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Large uncertainty in carbon uptake potential of land-based climate-change mitigation efforts
- 2018
-
Ingår i: Global Change Biology. - : Wiley. - 1354-1013. ; 24:7, s. 3025-3038
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Tidskriftsartikel (refereegranskat)abstract
- Most climate mitigation scenarios involve negative emissions, especially those that aim to limit global temperature increase to 2°C or less. However, the carbon uptake potential in land-based climate change mitigation efforts is highly uncertain. Here, we address this uncertainty by using two land-based mitigation scenarios from two land-use models (IMAGE and MAgPIE) as input to four dynamic global vegetation models (DGVMs; LPJ-GUESS, ORCHIDEE, JULES, LPJmL). Each of the four combinations of land-use models and mitigation scenarios aimed for a cumulative carbon uptake of ~130 GtC by the end of the century, achieved either via the cultivation of bioenergy crops combined with carbon capture and storage (BECCS) or avoided deforestation and afforestation (ADAFF). Results suggest large uncertainty in simulated future land demand and carbon uptake rates, depending on the assumptions related to land use and land management in the models. Total cumulative carbon uptake in the DGVMs is highly variable across mitigation scenarios, ranging between 19 and 130 GtC by year 2099. Only one out of the 16 combinations of mitigation scenarios and DGVMs achieves an equivalent or higher carbon uptake than achieved in the land-use models. The large differences in carbon uptake between the DGVMs and their discrepancy against the carbon uptake in IMAGE and MAgPIE are mainly due to different model assumptions regarding bioenergy crop yields and due to the simulation of soil carbon response to land-use change. Differences between land-use models and DGVMs regarding forest biomass and the rate of forest regrowth also have an impact, albeit smaller, on the results. Given the low confidence in simulated carbon uptake for a given land-based mitigation scenario, and that negative emissions simulated by the DGVMs are typically lower than assumed in scenarios consistent with the 2°C target, relying on negative emissions to mitigate climate change is a highly uncertain strategy.
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33. |
- Lindeskog, Mats, et al.
(författare)
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Implications of accounting for land use in simulations of ecosystem carbon cycling in Africa
- 2013
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Ingår i: Earth System Dynamics. - : Copernicus GmbH. - 2190-4979 .- 2190-4987. ; 4:2, s. 385-407
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Tidskriftsartikel (refereegranskat)abstract
- Dynamic global vegetation models (DGVMs) are important tools for modelling impacts of global change on ecosystem services. However, most models do not take full account of human land management and land use and land cover changes (LULCCs). We integrated croplands and pasture and their management and natural vegetation recovery and succession following cropland abandonment into the LPJ-GUESS DGVM. The revised model was applied to Africa as a case study to investigate the implications of accounting for land use on net ecosystem carbon balance (NECB) and the skill of the model in describing agricultural production and reproducing trends and patterns in vegetation structure and function. The seasonality of modelled monthly fraction of absorbed photosynthetically active radiation (FPAR) was shown to agree well with satellite-inferred normalised difference vegetation index (NDVI). In regions with a large proportion of cropland, the managed land addition improved the FPAR vs. NDVI fit significantly. Modelled 1991-1995 average yields for the seven most important African crops, representing potential optimal yields limited only by climate forcings, were generally higher than reported FAO yields by a factor of 2-6, similar to previous yield gap estimates. Modelled inter-annual yield variations during 1971-2005 generally agreed well with FAO statistics, especially in regions with pronounced climate seasonality. Modelled land-atmosphere carbon fluxes for Africa associated with land use change (0.07 PgC yr(-1) release to the atmosphere for the 1980s) agreed well with previous estimates. Cropland management options (residue removal, grass as cover crop) were shown to be important to the land-atmosphere carbon flux for the 20th century.
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34. |
- Lõhmus, Mare, et al.
(författare)
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What makes children learn how to swim? – health, lifestyle and environmental factors associated with swimming ability among children in the city of Malmö, Sweden
- 2022
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Ingår i: BMC Pediatrics. - : Springer Science and Business Media LLC. - 1471-2431. ; 22:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Swimming ability among children in the city of Malmö, Sweden is strongly affected by socioeconomic differences. We investigated to what extent mediating health and lifestyle factors, such as children’s eating, sleeping and physical activity habits, as well as the characteristics of the social and working environment at both school and home, could explain the socioeconomic gradient in swimming ability. Methods: Our study population included children who started their first-grade school-year in 2012 or 2013 at any of the public primary schools of Malmö, Sweden. Cross-sectional, self-reported questionnaire-based data about health status and swimming ability in the fourth grade (age 10) were included from the Pupil Health Database (ELSA) for 3468 children. Results: Children’s self-reported swimming ability was strongly associated with both individual- and school-based sociodemographic variables. Nine health, lifestyle and environmental variables were identified as potential mediators and included in the final model. Four of these variables, “Activity”, “Outdoor time”, “Social relationships at home and on the free time”, and “Positivity about future”, were significantly and positively associated with children’s ability to swim. Conclusions: Social support, optimism for the future and an active lifestyle were positively associated with children’s swimming skills; however, compared to the socioeconomic factors, these health- and lifestyle factors contributed very little. It is possible, that interventions concerning children’s swimming ability in lower socioeconomic neighbourhoods, should in addition to children’s swimming lessons, target the whole families with the goal of increasing their possibilities for socialising and engaging in different kinds of recreational activities.
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35. |
- Lu, Zhengyao, et al.
(författare)
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Natural decadal variability of global vegetation growth in relation to major decadal climate modes
- 2023
-
Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326 .- 1748-9318. ; 18:1
-
Tidskriftsartikel (refereegranskat)abstract
- The ongoing climate change can modulate the behavior of global vegetation and influence the terrestrial biosphere carbon sink. Past observation-based studies have mainly focused on the linear trend or interannual variability of the vegetation greenness, but could not explicitly deal with the effect of natural decadal variability due to the short length of observations. Here we put the variabilities revealed by remote sensing-based global leaf area index (LAI) from 1982 to 2015 into a long-term perspective with the help of ensemble Earth system model simulations of the historical period 1850-2014, with a focus on the low-frequency variability in the global LAI during the growing season. Robust decadal variability in the observed and modelled LAI was revealed across global terrestrial ecosystems, and it became stronger toward higher latitudes, accounting for over 50% of the total variability north of 40 degrees N. The linkage of LAI decadal variability to major natural decadal climate modes, such as the El Nino-Southern Oscillation decadal variability (ENSO-d), the Pacific decadal oscillation (PDO), and the Atlantic multidecadal oscillation (AMO), was analyzed. ENSO-d affects LAI by altering precipitation over large parts of tropical land. The PDO exerts opposite impacts on LAI in the tropics and extra-tropics due to the compensation between the effects of temperature and growing season length. The AMO effects are mainly associated with anomalous precipitation in North America and Europe but are mixed with long-term climate change impacts due to the coincident phase shift of the AMO which also induces North Atlantic basin warming. Our results suggest that the natural decadal variability of LAI can be largely explained by these decadal climate modes (on average 20% of the variance, comparable to linear changes, and over 40% in some ecosystems) which also can be potentially important in inducing the greening of the Earth of the past decades.
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36. |
- Lundevall, Magnus, et al.
(författare)
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Streaming Applications Over HSDPA in Mixed Service Scenarios
- 2004
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Ingår i: Proceedings of the 60th IEEE Vehicular Technology Conference. - 0780385217 ; , s. 841-845
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Konferensbidrag (refereegranskat)abstract
- High-speed downlink packet access (HSDPA) is included in release 5 of the WCDMA specifications to increase downlink capacity and bitrates. This paper considers performance aspects of streaming applications over HSDPA in a mixed streaming and best-effort service scenario. Different scheduling algorithms are evaluated with the aim of providing sufficient quality-of-service for streaming. The simulation results show that reasonable streaming performance can be achieved without service differentiation if a somewhat fair scheduler is used, and that a streaming-aware scheduler further can protect streaming quality-of-service in high load conditions.
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37. |
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38. |
- Lundström, Stefan, et al.
(författare)
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Narrativ kompetens : En förutsättning i multimodala textuniversum?
- 2010
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Ingår i: Tidskrift för litteraturvetenskap. - 1104-0556 .- 2001-094X. ; 2010:3-4, s. 107-117
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Tidskriftsartikel (refereegranskat)abstract
- Today’s media landscape is characterized by convergence culture, where the formats and the distribution of a narrative come together and create extensive multi modal text universe. At the same time the traditional division between producer and consumer is challenged. With examples from fan fiction and role playing games, the article discusses the notion of narrative competence as a possible way of understanding and describing the participation in multi modal text universe. Some of the things that characterize narrative competence are social interplay in a collective intelligence, to be able to discern plots and make creative imitations and to develop a meta reflective ability to be able to meet, try and understand one’s own reactions. One of the conclusions in the article is that if school education wishes to be experienced as relevant among students, it should include narrative competence. At the same time it will also increase the possibilities of reaching democratic goals.
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39. |
- Lundström, Stefan, et al.
(författare)
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Playing fiction: The use of semiotic resources in role play
- 2014
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Ingår i: Education Inquiry. - : Informa UK Limited. - 2000-4508. ; 5:1, s. 149-166
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Tidskriftsartikel (refereegranskat)abstract
- By taking two different kinds of role playing as examples, this article explores how semiotic resources are utilised within a certain context. Regarding these role-playing activities as examples of participative narratives, we discuss how the playing and fiction interaction works as semiotic remediation practices for teenagers and young adults. While actively becoming part of the story and ‘making’ themselves in interaction with fiction, they use semiotic resources not usually included in literacy competencies such as the body and various artifacts. This kind of participation in narrative indicates that we have a need for play not only as a first step in our socialisation to become a reader, but also as a tool for reading development throughout life.
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40. |
- Ma, Jianyong, et al.
(författare)
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Assessing the impacts of agricultural managements on soil carbon stocks, nitrogen loss, and crop production - a modelling study in eastern Africa
- 2022
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 19:8, s. 2145-2169
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Tidskriftsartikel (refereegranskat)abstract
- Improved agricultural management plays a vital role in protecting soils from degradation in eastern Africa. Changing practices such as reducing tillage, fertilizer use, or cover crops are expected to enhance soil organic carbon (SOC) storage, with climate change mitigation co-benefits, while increasing crop production. However, the quantification of cropland management effects on agricultural ecosystems remains inadequate in this region. Here, we explored seven management practices and their potential effects on soil carbon (C) pools, nitrogen (N) losses, and crop yields under different climate scenarios, using the dynamic vegetation model LPJ-GUESS. The model performance is evaluated against observations from two long-term maize field trials in western Kenya and reported estimates from published sources. LPJ-GUESS generally produces soil C stocks and maize productivity comparable with measurements and mostly captures the SOC decline under some management practices that is observed in the field experiments. We found that for large parts of Kenya and Ethiopia, an integrated conservation agriculture practice (no-tillage, residue and manure application, and cover crops) increases SOC levels in the long term (+11g% on average), accompanied by increased crop yields (+22g%) in comparison to the conventional management. Planting nitrogen-fixing cover crops in our simulations is also identified as a promising individual practice in eastern Africa to increase soil C storage (+4g%) and crop production (+18g%), with low environmental cost of N losses (+24g%). These management impacts are also sustained in simulations of three future climate pathways. This study highlights the possibilities of conservation agriculture when targeting long-term environmental sustainability and food security in crop ecosystems, particularly for those with poor soil conditions in tropical climates.
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41. |
- Ma, Jianyong, et al.
(författare)
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Estimating the Global Influence of Cover Crops on Ecosystem Service Indicators in Croplands With the LPJ-GUESS Model
- 2023
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Ingår i: Earth's Future. - 2328-4277. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- Cover crops (CCs) can improve soil nutrient retention and crop production while providing climate change mitigation co-benefits. However, quantifying these ecosystem services across global agricultural lands remains inadequate. Here, we assess how the use of herbaceous CCs with and without biological nitrogen (N) fixation affects agricultural soil carbon stocks, N leaching, and crop yields, using the dynamic global vegetation model LPJ-GUESS. The model performance is evaluated with observations from worldwide field trials and modeled output further compared against previously published large-scale estimates. LPJ-GUESS broadly captures the enhanced soil carbon, reduced N leaching, and yield changes that are observed in the field. Globally, we found that combining N-fixing CCs with no-tillage technique could potentially increase soil carbon levels by 7% (+0.32 Pg C yr−1 in global croplands) while reducing N leaching loss by 41% (−7.3 Tg N yr−1) compared with fallow controls after 36 years of simulation since 2015. This integrated practice is accompanied by a 2% of increase in total crop production (+37 million tonnes yr−1 including wheat, maize, rice, and soybean) in the last decade of the simulation. The identified effects of CCs on crop productivity vary widely among main crop types and N fertilizer applications, with small yield changes found in soybean systems and highly fertilized agricultural soils. Our results demonstrate the possibility of conservation agriculture when targeting long-term environmental sustainability without compromising crop production in global croplands.
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42. |
- Ma, Jianyong, et al.
(författare)
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Modeling symbiotic biological nitrogen fixation in grain legumes globally with LPJ-GUESS (v4.0, r10285)
- 2022
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 15:2, s. 815-839
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Tidskriftsartikel (refereegranskat)abstract
- Biological nitrogen fixation (BNF) from grain legumes is of significant importance in global agricultural ecosystems. Crops with BNF capability are expected to support the need to increase food production while reducing nitrogen (N) fertilizer input for agricultural sustainability, but quantification of N fixing rates and BNF crop yields remains inadequate on a global scale. Here we incorporate two legume crops (soybean and faba bean) with BNF into a dynamic vegetation model LPJ-GUESS (Lund-Potsdam-Jena General Ecosystem Simulator). The performance of this new implementation is evaluated against observations from a range of water and N management trials. LPJ-GUESS generally captures the observed response to these management practices for legume biomass production, soil N uptake, and N fixation, despite some deviations from observations in some cases. Globally, simulated BNF is dominated by soil moisture and temperature, as well as N fertilizer addition. Annual inputs through BNF are modeled to be 11.6±2.2ĝ€¯Tgĝ€¯N for soybean and 5.6±1.0ĝ€¯Tgĝ€¯N for all pulses, with a total fixation of 17.2±2.9ĝ€¯Tgĝ€¯Nĝ€¯yr-1 for all grain legumes during the period 1981-2016 on a global scale. Our estimates show good agreement with some previous statistical estimates but are relatively high compared to some estimates for pulses. This study highlights the importance of accounting for legume N fixation process when modeling C-N interactions in agricultural ecosystems, particularly when it comes to accounting for the combined effects of climate and land-use change on the global terrestrial N cycle.
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43. |
- Martín Belda, David, et al.
(författare)
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LPJ-GUESS/LSMv1.0 : A next-generation land surface model with high ecological realism
- 2022
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 15:17, s. 6709-6745
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Tidskriftsartikel (refereegranskat)abstract
- Land biosphere processes are of central importance to the climate system. Specifically, ecosystems interact with the atmosphere through a variety of feedback loops that modulate energy, water, and CO2 fluxes between the land surface and the atmosphere across a wide range of temporal and spatial scales. Human land use and land cover modification add a further level of complexity to land-atmosphere interactions. Dynamic global vegetation models (DGVMs) attempt to capture land ecosystem processes and are increasingly incorporated into Earth system models (ESMs), which makes it possible to study the coupled dynamics of the land biosphere and the climate. In this work we describe a number of modifications to the LPJ-GUESS DGVM, aimed at enabling direct integration into an ESM. These include energy balance closure, the introduction of a sub-daily time step, a new radiative transfer scheme, and improved soil physics. The implemented modifications allow the model (LPJ-GUESS/LSM) to simulate the diurnal exchange of energy, water, and CO2 between the land ecosystem and the atmosphere and thus provide surface boundary conditions to an atmospheric model over land. A site-based evaluation against FLUXNET2015 data shows reasonable agreement between observed and modelled sensible and latent heat fluxes. Differences in predicted ecosystem function between standard LPJ-GUESS and LPJ-GUESS/LSM vary across land cover types. We find that the emerging ecosystem composition and carbon fluxes are sensitive to both the choice of stomatal conductance model and the response of plant water uptake to soil moisture. The new implementation described in this work lays the foundation for using the well-established LPJ-GUESS DGVM as an alternative land surface model (LSM) in coupled land-biosphere-climate studies, where an accurate representation of ecosystem processes is essential.
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44. |
- Minoli, Sara, et al.
(författare)
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Global Response Patterns of Major Rainfed Crops to Adaptation by Maintaining Current Growing Periods and Irrigation
- 2019
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Ingår i: Earth's Future. - 2328-4277. ; 7:12, s. 1464-1480
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Tidskriftsartikel (refereegranskat)abstract
- Increasing temperature trends are expected to impact yields of major field crops by affecting various plant processes, such as phenology, growth, and evapotranspiration. However, future projections typically do not consider the effects of agronomic adaptation in farming practices. We use an ensemble of seven Global Gridded Crop Models to quantify the impacts and adaptation potential of field crops under increasing temperature up to 6 K, accounting for model uncertainty. We find that without adaptation, the dominant effect of temperature increase is to shorten the growing period and to reduce grain yields and production. We then test the potential of two agronomic measures to combat warming-induced yield reduction: (i) use of cultivars with adjusted phenology to regain the reference growing period duration and (ii) conversion of rainfed systems to irrigated ones in order to alleviate the negative temperature effects that are mediated by crop evapotranspiration. We find that cultivar adaptation can fully compensate global production losses up to 2 K of temperature increase, with larger potentials in continental and temperate regions. Irrigation could also compensate production losses, but its potential is highest in arid regions, where irrigation expansion would be constrained by water scarcity. Moreover, we discuss that irrigation is not a true adaptation measure but rather an intensification strategy, as it equally increases production under any temperature level. In the tropics, even when introducing both adapted cultivars and irrigation, crop production declines already at moderate warming, making adaptation particularly challenging in these areas.
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45. |
- Müller, Christoph, et al.
(författare)
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Exploring uncertainties in global crop yield projections in a large ensemble of crop models and CMIP5 and CMIP6 climate scenarios
- 2021
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 16:3
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Tidskriftsartikel (refereegranskat)abstract
- Concerns over climate change are motivated in large part because of their impact on human society. Assessing the effect of that uncertainty on specific potential impacts is demanding, since it requires a systematic survey over both climate and impacts models. We provide a comprehensive evaluation of uncertainty in projected crop yields for maize, spring and winter wheat, rice, and soybean, using a suite of nine crop models and up to 45 CMIP5 and 34 CMIP6 climate projections for three different forcing scenarios. To make this task computationally tractable, we use a new set of statistical crop model emulators. We find that climate and crop models contribute about equally to overall uncertainty. While the ranges of yield uncertainties under CMIP5 and CMIP6 projections are similar, median impact in aggregate total caloric production is typically more negative for the CMIP6 projections (+1% to −19%) than for CMIP5 (+5% to −13%). In the first half of the 21st century and for individual crops is the spread across crop models typically wider than that across climate models, but we find distinct differences between crops: globally, wheat and maize uncertainties are dominated by the crop models, but soybean and rice are more sensitive to the climate projections. Climate models with very similar global mean warming can lead to very different aggregate impacts so that climate model uncertainties remain a significant contributor to agricultural impacts uncertainty. These results show the utility of large-ensemble methods that allow comprehensively evaluating factors affecting crop yields or other impacts under climate change. The crop model ensemble used here is unbalanced and pulls the assumption that all projections are equally plausible into question. Better methods for consistent model testing, also at the level of individual processes, will have to be developed and applied by the crop modeling community.
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46. |
- Müller, Christoph, et al.
(författare)
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Global gridded crop model evaluation : Benchmarking, skills, deficiencies and implications
- 2017
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 10:4, s. 1403-1422
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Tidskriftsartikel (refereegranskat)abstract
- Crop models are increasingly used to simulate crop yields at the global scale, but so far there is no general framework on how to assess model performance. Here we evaluate the simulation results of 14 global gridded crop modeling groups that have contributed historic crop yield simulations for maize, wheat, rice and soybean to the Global Gridded Crop Model Intercomparison (GGCMI) of the Agricultural Model Intercomparison and Improvement Project (AgMIP). Simulation results are compared to reference data at global, national and grid cell scales and we evaluate model performance with respect to time series correlation, spatial correlation and mean bias. We find that global gridded crop models (GGCMs) show mixed skill in reproducing time series correlations or spatial patterns at the different spatial scales. Generally, maize, wheat and soybean simulations of many GGCMs are capable of reproducing larger parts of observed temporal variability (time series correlation coefficients (r) of up to 0.888 for maize, 0.673 for wheat and 0.643 for soybean at the global scale) but rice yield variability cannot be well reproduced by most models. Yield variability can be well reproduced for most major producing countries by many GGCMs and for all countries by at least some. A comparison with gridded yield data and a statistical analysis of the effects of weather variability on yield variability shows that the ensemble of GGCMs can explain more of the yield variability than an ensemble of regression models for maize and soybean, but not for wheat and rice. We identify future research needs in global gridded crop modeling and for all individual crop modeling groups. In the absence of a purely observation-based benchmark for model evaluation, we propose that the best performing crop model per crop and region establishes the benchmark for all others, and modelers are encouraged to investigate how crop model performance can be increased. We make our evaluation system accessible to all crop modelers so that other modeling groups can also test their model performance against the reference data and the GGCMI benchmark.
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47. |
- Müller, Christoph, et al.
(författare)
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Substantial Differences in Crop Yield Sensitivities Between Models Call for Functionality-Based Model Evaluation
- 2024
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Ingår i: Earth's Future. - 2328-4277. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Crop models are often used to project future crop yield under climate and global change and typically show a broad range of outcomes. To understand differences in modeled responses, we analyzed modeled crop yield response types using impact response surfaces along four drivers of crop yield: carbon dioxide (C), temperature (T), water (W), and nitrogen (N). Crop yield response types help to understand differences in simulated responses per driver and their combinations rather than aggregated changes in yields as the result of simultaneous changes in various drivers. We find that models' sensitivities to the individual drivers are substantially different and often more different across models than across regions. There is some agreement across models with respect to the spatial patterns of response types but strong differences in the distribution of response types across models and their configurations suggests that models need to undergo further scrutiny. We suggest establishing standards in model evaluation based on emergent functionality not only against historical yield observations but also against dedicated experiments across different drivers to analyze emergent functional patterns of crop models.
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48. |
- Müller, Christoph, et al.
(författare)
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The Global Gridded Crop Model Intercomparison phase 1 simulation dataset
- 2019
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- The Global Gridded Crop Model Intercomparison (GGCMI) phase 1 dataset of the Agricultural Model Intercomparison and Improvement Project (AgMIP) provides an unprecedentedly large dataset of crop model simulations covering the global ice-free land surface. The dataset consists of annual data fields at a spatial resolution of 0.5 arc-degree longitude and latitude. Fourteen crop modeling groups provided output for up to 11 historical input datasets spanning 1901 to 2012, and for up to three different management harmonization levels. Each group submitted data for up to 15 different crops and for up to 14 output variables. All simulations were conducted for purely rainfed and near-perfectly irrigated conditions on all land areas irrespective of whether the crop or irrigation system is currently used there. With the publication of the GGCMI phase 1 dataset we aim to promote further analyses and understanding of crop model performance, potential relationships between productivity and environmental impacts, and insights on how to further improve global gridded crop model frameworks. We describe dataset characteristics and individual model setup narratives.
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49. |
- Oberpriller, Johannes, et al.
(författare)
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Climate and parameter sensitivity and induced uncertainties in carbon stock projections for European forests (using LPJ-GUESS 4.0)
- 2022
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 15:16, s. 6495-6519
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Tidskriftsartikel (refereegranskat)abstract
- Understanding uncertainties and sensitivities of projected ecosystem dynamics under environmental change is of immense value for research and climate change policy. Here, we analyze sensitivities (change in model outputs per unit change in inputs) and uncertainties (changes in model outputs scaled to uncertainty in inputs) of vegetation dynamics under climate change, projected by a state-of-the-art dynamic vegetation model (LPJ-GUESS v4.0) across European forests (the species Picea abies, Fagus sylvatica and Pinus sylvestris), considering uncertainties of both model parameters and environmental drivers. We find that projected forest carbon fluxes are most sensitive to photosynthesis-, water-, and mortality-related parameters, while predictive uncertainties are dominantly induced by environmental drivers and parameters related to water and mortality. The importance of environmental drivers for predictive uncertainty increases with increasing temperature. Moreover, most of the interactions of model inputs (environmental drivers and parameters) are between environmental drivers themselves or between parameters and environmental drivers. In conclusion, our study highlights the importance of environmental drivers not only as contributors to predictive uncertainty in their own right but also as modifiers of sensitivities and thus uncertainties in other ecosystem processes. Reducing uncertainty in mortality-related processes and accounting for environmental influence on processes should therefore be a focus in further model development.
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50. |
- Olin, Pontus, 1979-, et al.
(författare)
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Trapping of Water Drops by Defects on Superhydrophobic Surfaces
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this work the effect of line‑shaped defects on the motion of water drops on superhydrophobic surfaces have been investigated using high‑speed video. The defects were introduced on superhydrophobic wax surfaces by a simple scratching method. It is shown that the motion of the drop in the vicinity of the defect can be approximated by a damped harmonic oscillator. Whether a drop gets trapped or not while traversing the defect is determined by the incident speed and the characteristics of the oscillator, more specifically by the damping ratio z and the nondimensional forcing constant â. We also show that it is possible to predict the trapping speed as well as the exit speed using a simple work‑energy consideration in systems with negligible viscous dissipation.
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