| 1. |
- Hieronymus, M., et al.
(författare)
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On the Application of Machine Learning Techniques to Regression Problems in Sea Level Studies
- 2019
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Ingår i: Journal of Atmospheric and Oceanic Technology. - : American Meteorological Society. - 0739-0572 .- 1520-0426. ; 36:9, s. 1889-1902
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Tidskriftsartikel (refereegranskat)abstract
- Long sea level records with high temporal resolution are of paramount importance for future coastal protection and adaptation plans. Here we discuss the application of machine learning techniques to some regression problems commonly encountered when analyzing such time series. The performance of artificial neural networks is compared with that of multiple linear regression models on sea level data from the Swedish coast. The neural networks are found to be superior when local sea level forcing is used together with remote sea level forcing and meteorological forcing, whereas the linear models and the neural networks show similar performance when local sea level forcing is excluded. The overall performance of the machine learning algorithms is good, often surpassing that of the much more computationally costly numerical ocean models used at our institute.
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| 2. |
- Chen, Deliang, 1961, et al.
(författare)
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Summary of a workshop on extreme weather events in a warming world organized by the Royal Swedish Academy of Sciences
- 2020
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Ingår i: Tellus Series B-Chemical and Physical Meteorology. - : Stockholm University Press. - 1600-0889 .- 0280-6509. ; 72:1
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is not only about changes in means of climatic variables such as temperature, precipitation and wind, but also their extreme values which are of critical importance to human society and ecosystems. To inspire the Swedish climate research community and to promote assessments of international research on past and future changes in extreme weather events against the global climate change background, the Earth Science Class of the Royal Swedish Academy of Sciences organized a workshop entitled 'Extreme weather events in a warming world' in 2019. This article summarizes and synthesizes the key points from the presentations and discussions of the workshop on changes in floods, droughts, heat waves, as well as on tropical cyclones and extratropical storms. In addition to reviewing past achievements in these research fields and identifying research gaps with a focus on Sweden, future challenges and opportunities for the Swedish climate research community are highlighted.
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| 3. |
- de Rouw, Nikki, et al.
(författare)
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Rethinking the Application of Pemetrexed for Patients with Renal Impairment : A Pharmacokinetic Analysis
- 2021
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Ingår i: Clinical Pharmacokinetics. - : ADIS INT LTD. - 0312-5963 .- 1179-1926. ; 60:5, s. 649-654
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Tidskriftsartikel (refereegranskat)abstract
- Background Pemetrexed is used for the treatment for non-small cell lung cancer and mesothelioma. Patients with renal impairment are withheld treatment with this drug as it is unknown what dose is well tolerated in this population. Objective The purpose of our study was to investigate the pharmacokinetics (PK) of pemetrexed in patients with renal impairment. Methods A population PK analysis of pemetrexed was performed using non-linear mixed-effects modelling with phase I data obtained from the manufacturer. Additionally, the impact of renal function on pemetrexed PK was assessed with a simulation study using the developed PK model and a previously developed PK model lacking the phase I data. Results The dataset included 548 paired observations of 47 patients, with a wide range of estimated glomerular filtration rates (eGFR; 14.4-145.6 mL/min). Pemetrexed PK were best described by a three-compartment model with eGFR (calculated using the Chronic Kidney Disease-Epidemiology Collaboration [CKD-EPI] formula) as a linear covariate on renal pemetrexed clearance. Using the developed model, we found that renal clearance accounts for up to 84% (95% confidence interval 69-98%) of total pemetrexed clearance, whereas the manufacturer previously reported a 50% contribution of renal clearance. Conclusion Renal function is more important for the clearance of pemetrexed than previously thought and this should be taken into account in patients with renal impairment. Furthermore, a third compartment may contribute to prolonged exposure to pemetrexed during drug washout.
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| 4. |
- Hieronymus, F., et al.
(författare)
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Determining maximal achievable effect sizes of antidepressant therapies in placebo-controlled trials
- 2021
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Ingår i: Acta Psychiatrica Scandinavica. - : Wiley. - 0001-690X .- 1600-0447. ; 144:3, s. 300-309
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Tidskriftsartikel (refereegranskat)abstract
- Objective Antidepressants outperform placebo with an effect size of around 0.30. It has been suggested that effect sizes as high as 0.875 are necessary for a minimal clinically important difference. Whether such effect sizes are achievable in placebo-controlled trials is unknown. Therefore, we aimed to assess what effect sizes are theoretically achievable in placebo-controlled trials of antidepressants. Methods Patient-level analyses comparing Hamilton Depression Rating Scale (HDRS-17) outcomes for simulated antidepressant therapies to placebo-treated participants (n = 2201) from clinical trials of selective serotonin reuptake inhibitors. Results An optimally effective antidepressant, where all treated participants achieve HDRS-17 scores comparable to those displayed by healthy volunteers (remission-type model), had a maximum effect size of 1.75, with a mean difference of 11.6 points on the HDRS-17. In simulations where patients received an additional 50% symptom reduction over that obtained with placebo (improvement-type model), the maximum effect size was 1.08 with a mean HDRS-17 difference of 7.2. When adjusting for normal rates of treatment discontinuation, maximum effect sizes were 1.10 (remission-type model) and 0.76 (improvement-type model) with HDRS-17 mean differences of 8.8 and 5.6, respectively. Conclusions Three methodological issues (i) a large and variable placebo response, (ii) a high rate of dropout and (iii) HDRS-17-ratings significantly larger than zero in healthy volunteers, reduce the degree of treatment-placebo separation achievable in depression trials. Assuming that those who discontinue treatment have only partial response, even a highly effective antidepressant would have difficulties surpassing such effect size cut-offs as have been suggested to signify a minimal clinically important difference.
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| 5. |
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| 6. |
- Hieronymus, M., et al.
(författare)
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Southern Baltic sea level extremes: tide gauge data, historic storms and confidence intervals
- 2021
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Ingår i: Boreal Environment Research. - 1239-6095. ; 26, s. 79-87
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge of extreme sea levels is important when planning housing developments and other infrastructure in coastal locations. The natural science basis of such plans are often return level-return period plots derived from tide gauge records that typically stretch from a few decades to a century. Coastal planners, however. often require return levels associated with return periods that are much longer than these tide gauge records in their planning. Moreover, return level estimates are known to be sensitive to outliers and can have significant biases. Here, we quantify different confidence intervals that arc applicable to such return level estimates. and discuss their usability for coastal planning in the context of historic data from the Baltic Sea flood in 1872. Two types of commonly used confidence intervals are found to be too narrow to capture a plausible range that includes the 1872 Baltic Sea flood. A parametric bootstrapping method is then introduced, which gives a reasonable range even when this extreme flood is considered.
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| 7. |
- López, E, et al.
(författare)
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[Psychedelic psychiatry]
- 2024
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Ingår i: Lakartidningen. - 1652-7518. ; 121
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Döscher, Ralf, et al.
(författare)
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The EC-Earth3 Earth system model for the Coupled Model Intercomparison Project 6
- 2022
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 15:7, s. 2973-3020
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Tidskriftsartikel (refereegranskat)abstract
- The Earth system model EC-Earth3 for contributions to CMIP6 is documented here, with its flexible coupling framework, major model configurations, a methodology for ensuring the simulations are comparable across different high-performance computing (HPC) systems, and with the physical performance of base configurations over the historical period. The variety of possible configurations and sub-models reflects the broad interests in the EC-Earth community. EC-Earth3 key performance metrics demonstrate physical behavior and biases well within the frame known from recent CMIP models. With improved physical and dynamic features, new Earth system model (ESM) components, community tools, and largely improved physical performance compared to the CMIP5 version, EC-Earth3 represents a clear step forward for the only European community ESM. We demonstrate here that EC-Earth3 is suited for a range of tasks in CMIP6 and beyond.
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| 9. |
- Hieronymus, C. F., et al.
(författare)
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A dynamical model for generating Eurasian lithospheric stress and strain rate fields : Effect of rheology and cratons
- 2008
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 113:B7, s. B07404-
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Tidskriftsartikel (refereegranskat)abstract
- For most continents, stress models driven by plate boundary forces have successfully reproduced the main characteristics of the stress field. However, Eurasia has remained a challenge due to its large areas of intraplate deformation. We present a set of three-dimensional models of the upper mantle lithosphere system for a simplified geometry of the Eurasian plate where we try to match the first-order characteristics of the stress and strain rate fields simultaneously. For typical elastic, viscous, or plastic rheologies, high stress levels are required in order to produce realistic convergence rates between India and Asia. Our models show robustly that such stresses are transmitted throughout most of the plate, dominating locally generated stresses even in distal regions such as Europe in a manner that is not compatible with observations. Cratons with roots that extend deep into the mantle are unable to provide a significant stress-shielding effect unless the viscosity contrast between the asthenosphere and the underlying mantle is around 100 or greater. A damage rheology for the lithosphere with history-dependent behavior and material softening by a viscosity reduction of several orders of magnitude is shown to eliminate this conundrum. Continental convergence at high velocity but low stress is facilitated by the formation of long-lived shear zones similar to those observed north of the Himalayas. The low stress associated with the collision, together with the decoupling effect of the shear zones, causes the distal stress field in Europe to be controlled by the effects of the neighboring boundaries in agreement with observations.
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