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3. Event peak flow dataset for spatial counterfactual events, Germany

Author

Nguyen, V.D., Merz, B., Guse, B., Han, L., Guan, X., Rakovec, Oldrich, Samaniego, Luis, Ahrens, B., Vorogushyn, S., Nguyen, V.D., Merz, B., Guse, B., Han, L., Guan, X., Rakovec, Oldrich, Samaniego, Luis, Ahrens, B., and Vorogushyn, S.

Abstract

Flood-prone people and decision-makers are often unwilling to discuss and prepare for exceptional events, as such events are hard to perceive and out of experience for most people. Once an exceptional flood occurs, affected people and decision-makers are able to learn from this event. However, this learning is often focussed narrowly on the specific disaster experienced, thus missing an opportunity to explore and prepare for even more severe, or different, events. We propose spatial counterfactual floods as a means to motivate society to discuss exceptional events and suitable risk management strategies. We generate a set of extreme floods across Germany by shifting observed rainfall events in space and then propagating these shifted fields through a flood model. We argue that the storm tracks that caused past floods could have developed several tens of km away from the actual tracks. The set of spatial counterfactual floods generated contains events which are more than twice as severe as the most disastrous flood since 1950 in Germany. Moreover, regions that have been spared from havoc in the past should not feel safe, as they could have been badly hit as well. We propose spatial counterfactuals as a suitable approach to overcome society's unwillingness to think about and prepare for exceptional floods expected to occur more frequently in a warmer world.

Published
2024

4. The value of large-scale climatic indices for monthly forecasting severity of widespread flooding using dilated convolutional neural networks

Author

Tarasova, Larisa, Ahrens, B., Hoff, A., Lall, U., Tarasova, Larisa, Ahrens, B., Hoff, A., and Lall, U.

Abstract

Spatially co-occurring floods pose a threat to the resilience and recovery of the communities. Their timely forecasting plays a crucial role for increasing flood preparedness and limiting associated losses. In this study we investigated the potential of a dilated Convolutional Neural Network (dCNN) model conditioned on large-scale climatic indices and antecedent precipitation to forecast monthly severity of widespread flooding (i.e., spatially co-occurring floods) in Germany with 1 month lead time. The severity was estimated from 63 years of daily streamflow series as the sum of concurrent exceedances of at-site 2-year return periods within a given month across 172 mesoscale catchments (median area 516 km2). The model was trained individually for the whole country and three diverse hydroclimatic regions to provide insights on heterogeneity of model performance and flood drivers. Our results showed a considerable potential for forecasting widespread flood severity using dCNN especially as the length of training series increases. However, event-based evaluation of model skill indicates large underestimation for rainfall-generated floods during dry conditions despite overall lower severity of these events compared to the rain-on-snow floods. Feature attribution and wavelet coherence analyses both indicated considerable difference in the major flood drivers in three regions. While the flooding in North-Eastern region is strongly affected by the Baltic Sea, the North-Western region is affected more by global patterns associated with the El-Niño activity. In the Southern region in addition to global patterns we detected the effect of the Mediterranean Sea, while antecedent precipitation plays a less important role in this region.

Published
2024

5. Spatial counterfactuals to explore disastrous flooding

Author

Merz, B., Nguyen, V.D., Guse, B., Han, L., Guan, X., Rakovec, Oldrich, Samaniego, Luis, Ahrens, B., Vorogushyn, S., Merz, B., Nguyen, V.D., Guse, B., Han, L., Guan, X., Rakovec, Oldrich, Samaniego, Luis, Ahrens, B., and Vorogushyn, S.

Abstract

Flood-prone people and decision-makers are often unwilling to discuss and prepare for exceptional events, as such events are hard to perceive and out of experience for most people. Once an exceptional flood occurs, affected people and decision-makers are able to learn from this event. However, this learning is often focussed narrowly on the specific disaster experienced, thus missing an opportunity to explore and prepare for even more severe, or different, events. We propose spatial counterfactual floods as a means to motivate society to discuss exceptional events and suitable risk management strategies. We generate a set of extreme floods across Germany by shifting observed rainfall events in space and then propagating these shifted fields through a flood model. We argue that the storm tracks that caused past floods could have developed several tens of km away from the actual tracks. The set of spatial counterfactual floods generated contains events which are more than twice as severe as the most disastrous flood since 1950 in Germany. Moreover, regions that have been spared from havoc in the past should not feel safe, as they could have been badly hit as well. We propose spatial counterfactuals as a suitable approach to overcome society's unwillingness to think about and prepare for exceptional floods expected to occur more frequently in a warmer world.

Published
2024

9. A first-of-its-kind multi-model convection permitting ensemble for investigating convective phenomena over Europe and the Mediterranean

Author

Coppola, Erika, Sobolowski, Stefan, Pichelli, E., Raffaele, F., Ahrens, B., Anders, I., Ban, N., Bastin, S., Belda, M., Belusic, D., Caldas-Alvarez, A., Cardoso, R. M., Davolio, S., Dobler, A., Fernandez, J., Fita, L., Fumiere, Q., Giorgi, F., Goergen, K., Güttler, I., Halenka, T., Heinzeller, D., Hodnebrog, Ø., Jacob, D., Kartsios, S., Katragkou, E., Kendon, E., Khodayar, S., Kunstmann, H., Knist, S., Lavín-Gullón, A., Lind, P., Lorenz, T., Maraun, D., Marelle, L., van Meijgaard, E., Milovac, J., Myhre, G., Panitz, H.-J., Piazza, M., Raffa, M., Raub, T., Rockel, B., Schär, C., Sieck, K., Soares, P. M. M., Somot, S., Srnec, L., Stocchi, P., Tölle, M. H., Truhetz, H., Vautard, R., de Vries, H., and Warrach-Sagi, K.

Published
2020
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11. Global covariation of carbon turnover times with climate in terrestrial ecosystems

Author

Carvalhais, N, Forkel, M, Khomik, M, Bellarby, J, Jung, M, Migliavacca, M, Μu, M, Saatchi, S, Santoro, M, Thurner, M, Weber, U, Ahrens, B, Beer, C, Cescatti, A, Randerson, JT, and Reichstein, M

Subjects
General Science & Technology
Abstract

© 2014 Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. The response of the terrestrial carbon cycle to climate change is among the largest uncertainties affecting future climate change projections. The feedback between the terrestrial carbon cycle and climate is partly determined by changes in the turnover time of carbon in land ecosystems, which in turn is an ecosystem property that emerges from the interplay between climate, soil and vegetation type. Here we present a global, spatially explicit and observation-based assessment of whole-ecosystem carbon turnover times that combines new estimates of vegetation and soil organic carbon stocks and fluxes. We find that the overall mean global carbon turnover time is years (95 per cent confidence interval). On average, carbon resides in the vegetation and soil near the Equator for a shorter time than at latitudes north of 75° north (mean turnover times of 15 and 255 years, respectively). We identify a clear dependence of the turnover time on temperature, as expected from our present understanding of temperature controls on ecosystem dynamics. Surprisingly, our analysis also reveals a similarly strong association between turnover time and precipitation. Moreover, we find that the ecosystem carbon turnover times simulated by state-of-the-art coupled climate/carbon-cycle models vary widely and that numerical simulations, on average, tend to underestimate the global carbon turnover time by 36 per cent. The models show stronger spatial relationships with temperature than do observation-based estimates, but generally do not reproduce the strong relationships with precipitation and predict faster carbon turnover in many semi-arid regions. Our findings suggest that future climate/carbon-cycle feedbacks may depend more strongly on changes in the hydrological cycle than is expected at present and is considered in Earth system models.

Published
2014

12. Bayesian calibration of a soil organic carbon model using delta 14C measurements of soil organic carbon and heterotrophic respiration as joint constraints

Author

Ahrens, B., Reichstein, M., Borken, W., Muhr, J., Trumbore, S. E, and Wutzler, T.

Subjects
Bayesian analysis, calibration, carbon balance, carbon isotope, coniferous tree, forest soil, heterotrophy, organic soil, soil carbon, soil respiration, source-sink dynamics, temperate forest, Germany, United States
Abstract

Soils of temperate forests store significant amounts of organic matter and are considered to be net sinks of atmospheric CO2. Soil organic carbon (SOC) turnover has been studied using the Δ14C values of bulk SOC or different SOC fractions as observational constraints in SOC models. Further, the Δ14C values of CO2 that evolved during the incubation of soil and roots have been widely used together with Δ14C of total soil respiration to partition soil respiration into heterotrophic respiration (HR) and rhizosphere respiration. However, these data have not been used as joint observational constraints to determine SOC turnover times. Thus, we focus on (1) how different combinations of observational constraints help to narrow estimates of turnover times and other parameters of a simple two-pool model, the Introductory Carbon Balance Model (ICBM); (2) whether relaxing the steady-state assumption in a multiple constraints approach allows the source/sink strength of the soil to be determined while estimating turnover times at the same time. To this end ICBM was adapted to model SOC and SO14C in parallel with litterfall and the Δ14C of litterfall as driving variables. The Δ14C of the atmosphere with its prominent bomb peak was used as a proxy for the Δ14C of litterfall. Data from three spruce-dominated temperate forests in Germany and the USA (Coulissenhieb II, Solling D0 and Howland Tower site) were used to estimate the parameters of ICBM via Bayesian calibration. Key findings are as follows: (1) the joint use of all four observational constraints (SOC stock and its Δ14C, HR flux and its Δ14C) helped to considerably narrow turnover times of the young pool (primarily by Δ14C of HR) and the old pool (primarily by Δ14C of SOC). Furthermore, the joint use of all observational constraints made it possible to constrain the humification factor in ICBM, which describes the fraction of the annual outflux from the young pool that enters the old pool. The Bayesian parameter estimation yielded the following turnover times (mean ± standard deviation) for SOC in the young pool: Coulissenhieb II 1.1 ± 0.5 years, Solling D0 5.7 ± 0.8 years and Howland Tower 0.8 ± 0.4 years. Turnover times for the old pool were 377 ± 61 years (Coulissenhieb II), 313 ± 66 years (Solling D0) and 184 ± 42 years (Howland Tower), respectively. (2) At all three sites the multiple constraints approach was not able to determine if the soil has been losing or storing carbon. Nevertheless, the relaxed steady-state assumption hardly introduced any additional uncertainty for the other parameter estimates. Overall the results suggest that using Δ14C data from more than one carbon pool or flux helps to better constrain SOC models.

Published
2014

13. Bayesian calibration of a soil organic carbon model using δ14C measurements of soil organic carbon and heterotrophic respiration as joint constraints

Author

Ahrens, B, Reichstein, M, Borken, W, Muhr, J, Trumbore, SE, and Wutzler, T

Abstract

Soils of temperate forests store significant amounts of organic matter and are considered to be net sinks of atmospheric CO2. Soil organic carbon (SOC) turnover has been studied using the δ14C values of bulk SOC or different SOC fractions as observational constraints in SOC models. Further, the δ14C values of CO2 that evolved during the incubation of soil and roots have been widely used together with δ14C of total soil respiration to partition soil respiration into heterotrophic respiration (HR) and rhizosphere respiration. However, these data have not been used as joint observational constraints to determine SOC turnover times. Thus, we focus on (1) how different combinations of observational constraints help to narrow estimates of turnover times and other parameters of a simple two-pool model, the Introductory Carbon Balance Model (ICBM); (2) whether relaxing the steady-state assumption in a multiple constraints approach allows the source/sink strength of the soil to be determined while estimating turnover times at the same time. To this end ICBM was adapted to model SOC and SO14C in parallel with litterfall and the δ14C of litterfall as driving variables. The δ14C of the atmosphere with its prominent bomb peak was used as a proxy for the δ14C of litterfall. Data from three spruce-dominated temperate forests in Germany and the USA (Coulissenhieb II, Solling D0 and Howland Tower site) were used to estimate the parameters of ICBM via Bayesian calibration. Key findings are as follows: (1) the joint use of all four observational constraints (SOC stock and its δ14C, HR flux and its δ14C) helped to considerably narrow turnover times of the young pool (primarily by δ14C of HR) and the old pool (primarily by δ14C of SOC). Furthermore, the joint use of all observational constraints made it possible to constrain the humification factor in ICBM, which describes the fraction of the annual outflux from the young pool that enters the old pool. The Bayesian parameter estimation yielded the following turnover times (mean ± standard deviation) for SOC in the young pool: Coulissenhieb II 1.1 ± 0.5 years, Solling D0 5.7 ± 0.8 years and Howland Tower 0.8 ± 0.4 years. Turnover times for the old pool were 377 ± 61 years (Coulissenhieb II), 313 ± 66 years (Solling D0) and 184 ± 42 years (Howland Tower), respectively. (2) At all three sites the multiple constraints approach was not able to determine if the soil has been losing or storing carbon. Nevertheless, the relaxed steady-state assumption hardly introduced any additional uncertainty for the other parameter estimates. Overall the results suggest that using δ14C data from more than one carbon pool or flux helps to better constrain SOC models. © 2014 Author(s).

Published
2014

14. Bicategorical type theory: semantics and syntax

Author

Ahrens, B., North, P.R., Weide, Niels van der, Ahrens, B., North, P.R., and Weide, Niels van der

Abstract

Contains fulltext : 298864.pdf (Publisher’s version ) (Open Access), 17 november 2023

Published
2023

15. MED-CORDEX INITIATIVE FOR MEDITERRANEAN CLIMATE STUDIES

Author

Ruti, P. M., Somot, S., Giorgi, F., Dubois, C., Flaounas, E., Obermann, A., Dell’Aquila, A., Pisacane, G., Harzallah, A., Lombardi, E., Ahrens, B., Akhtar, N., Alias, A., Arsouze, T., Aznar, R., Bastin, S., Bartholy, J., Béranger, K., Beuvier, J., Bouffies-Cloché, S., Brauch, J., Cabos, W., Calmanti, S., Calvet, J.-C., Carillo, A., Conte, D., Coppola, E., Djurdjevic, V., Drobinski, P., Elizalde-Arellano, A., Gaertner, M., Galàn, P., Gallardo, C., Gualdi, S., Goncalves, M., Jorba, O., Jordà, G., L’Heveder, B., Lebeaupin-Brossier, C., Li, L., Liguori, G., Lionello, P., Maciàs, D., Nabat, P., Önol, B., Raikovic, B., Ramage, K., Sevault, F., Sannino, G., Struglia, M. V., Sanna, A., Torma, C., and Vervatis, V.

Published
2016

18. Site level evaluation of LS3MIP models’ hydrothermal dynamics in frozen soil regions

Author

Luo, Z. and Ahrens, B.

Abstract

Given the climate change and more frequent extreme climate events, frozen soils face a potential future extensive degradation. Climate models allow us to understand the possible future course of frozen soil and its effects towards local and global climate. Snow and soil hydrothermal dynamics are the most important parts of the frozen soil land surface process. There have been substantial efforts made to improve snow simulation. Some climate models are already able to realistically reproduce the variability of the snow and its physical parameters. Soil water has a direct impact on soil hydrothermal parameters, topography, and local water circulation under the repeatedly freeze-thaw process. Frequent occurrence of phase change in soil make frozen soil unique in land process simulating. LS3MIP provides us the opportunity to compare the snow and soil moisture condition between a set of climate models’ land components under identical forcing. We collected more than 200 stations in Siberia and Alaska recording snow depth, 2 m air temperature, soil temperature and soil moisture. Together with ERA5-Land reanalysis data, evaluations are done for LS3MIP models. Based on the present results, significant differences are found between the models, especially in terms of soil water content. We will make further analysis to identify the sources of these disagreements., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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20. Forensische Toxikologie

Author

Müller, R. K., Aderjan, R., Ahrens, B., Bernhard, W., Bothe, H.-K., Demme, U., Drasch, G., Engewald, W., Giebelmann, R., Grosse, J., Kauert, G., Kijewski, H., Köppel, C., Krämer, T., Maurer, H. H., Mebs, D., von Meyer, L., Möller, M. R., Otto, M., Peters, F. T., Pragst, F., Sachs, H., Salzer, R., Schmoldt, A., Schütz, H., Teske, J., Thieme, D., Tiess, D., Trauer, H., Wahl, A., Werner, G., Wichitill, J., Zschunke, A., Madea, Burkhard, editor, and Brinkmann, Bernd, editor

Published
2003
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21. Bicategories in univalent foundations

Author

Ahrens, B., Frumin, Dan, Maggesi, M., Veltri, Niccolo, Weide, Niels van der, Ahrens, B., Frumin, Dan, Maggesi, M., Veltri, Niccolo, and Weide, Niels van der

Abstract

25 maart 2022, Contains fulltext : 284064.pdf (Publisher’s version ) (Open Access)

Published
2022

22. S3 guideline Allergy Prevention

Author

Kopp, M., V, Muche-Borowski, C., Abou-Dakn, M., Ahrens, B., Beyer, K., Blumchen, K., Bubel, P., Chaker, A., Cremer, M., Ensenauer, R., Gerstlauer, M., Gieler, U., Hubner, I. M., Horak, F., Klimek, L., Koletzko, B., V, Koletzko, S., Lau, S., Lob-Corzilius, T., Nemat, K., Peters, E. M. J., Pizzulli, A., Reese, I, Rolinck-Werninghaus, C., Rouw, E., Schaub, B., Schmidt, S., Steiss, J. O., Striegel, A. K., Szepfalusi, Z., Schlembach, D., Spindler, T., Taube, C., Trendelenburg, V, Treudler, R., Umpfenbach, U., Vogelberg, C., Wagenmann, M., Weissenborn, A., Werfel, T., Worm, M., Sitter, H., Hamelmann, E., Kopp, M., V, Muche-Borowski, C., Abou-Dakn, M., Ahrens, B., Beyer, K., Blumchen, K., Bubel, P., Chaker, A., Cremer, M., Ensenauer, R., Gerstlauer, M., Gieler, U., Hubner, I. M., Horak, F., Klimek, L., Koletzko, B., V, Koletzko, S., Lau, S., Lob-Corzilius, T., Nemat, K., Peters, E. M. J., Pizzulli, A., Reese, I, Rolinck-Werninghaus, C., Rouw, E., Schaub, B., Schmidt, S., Steiss, J. O., Striegel, A. K., Szepfalusi, Z., Schlembach, D., Spindler, T., Taube, C., Trendelenburg, V, Treudler, R., Umpfenbach, U., Vogelberg, C., Wagenmann, M., Weissenborn, A., Werfel, T., Worm, M., Sitter, H., and Hamelmann, E.

Abstract

Background: The persistently high prevalence of allergic diseases in Western industrial nations and the limited possibilities of causal therapy make evidence-based recommendations for primary prevention necessary. Methods: The recommendations of the S3 guideline Allergy Prevention, published in its last version in 2014, were revised and consulted on the basis of a current systematic literature search. The evidence search was conducted for the period 06/2013 - 11/2020 in the electronic databases Cochrane and MEDLINE, as well as in the reference lists of current reviews and through references from experts. The literature found was screened in two filtering processes, first by title and abstract, and the remaining papers were screened in the full text for relevance. The studies included after this were sorted by level of evidence, and the study quality was indicated in terms of potential bias (low/high). The revised recommendations were formally agreed and consented upon with the participation of representatives of the relevant professional societies and (self-help) organizations (nominal group process). Of 5,681 hits, 286 studies were included and assessed. Results: Recommendations on maternal nutrition during pregnancy and breastfeeding as well as on infant nutrition in the first months of life again play an important role in the updated guideline: Many of the previous recommendations were confirmed by the current data. It was specified that breastfeeding should be exclusive for the first 4 - 6 months after birth, if possible, and that breastfeeding should continue with the introduction of complementary foods. A new recommendation is that supplementary feeding of cow's milk-based formula should be avoided in the first days of life if the mother wishes to breastfeed. Furthermore, it was determined that the evidence for a clear recommendation for hydrolyzed infant formula in non-breastfed infants at risk is currently no longer sufficient. It is therefore currently reco

Published
2022

23. S3-Leitlinie Allergieprävention

Author

Kopp, M.V., primary, Muche-Borowski, C., additional, Abou-Dakn, M., additional, Ahrens, B., additional, Beyer, K., additional, Blümchen, K., additional, Bubel, P., additional, Chaker, A., additional, Cremer, M., additional, Ensenauer, R., additional, Gerstlauer, M., additional, Gieler, U., additional, Hübner, I.M., additional, Horak, F., additional, Klimek, L., additional, Koletzko, B.V., additional, Koletzko, S., additional, Lau, S., additional, Lob-Corzilius, T., additional, Nemat, K., additional, Peters, E.M.J., additional, Pizzulli, A., additional, Reese, I., additional, Rolinck-Werninghaus, C., additional, Rouw, E., additional, Schaub, B., additional, Schmidt, S., additional, Steiß, J.O., additional, Striegel, A.K., additional, Szépfalusi, Z., additional, Schlembach, D., additional, Spindler, T., additional, Taube, C., additional, Trendelenburg, V., additional, Treudler, R., additional, Umpfenbach, U., additional, Vogelberg, C., additional, Wagenmann, M., additional, Weißenborn, A., additional, Werfel, T., additional, Worm, M., additional, Sitter, H., additional, and Hamelmann, E., additional

Published
2022
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24. Flood event and catchment characteristics in Germany and Austria

Author

Macdonald, E., Merz, B., Ullrich, S., Lüdtke, S., Schröter, K., Guse, B., Wietzke, L., Kemter, M., Ahrens, B., and Vorogushyn, S.

Abstract

The dataset comprises a range of variables describing characteristics of flood events and river catchments for 480 gauging stations in Germany and Austria. The event characteristics are asscoiated with annual maximum flood events in the period from 1951 to 2010. They include variables on event precipitation, antecedent catchment state, event catchment response, event timing, and event types. The catchment characteristics include variables on catchment area, catchment wetness, tail heaviness of rainfall, nonlinearity of catchment response, and synchronicity of precipitation and catchment state. The variables were compiled as potential predictors of heavy tail behaviour of flood peak distributions. They are based on gauge observations of discharge, E-OBS meteorological data (Haylock et al. 2008), mHM hydrological model simulations (Samaniego et al., 2010), 4DAS climate reanalysis data (Primo et al., 2019), and the 25x25 m resolution EU-DEM v1.1. A short description of the data processing is included in the file inventory and more details can be found in Macdonald et al. (2022).

Published
2022

26. S3-Leitlinie Allergieprävention

Author

Kopp, Matthias V., Muche-Borowski, C., Abou-Dakn, M., Ahrens, B., Beyer, K., Blümchen, K., Bubel, P., Chaker, A., Cremer, M., Ensenauer, R., Gerstlauer, M., Gieler, U., Hübner, I.M., Horak, F., Klimek, L., Koletzko, B.V., Koletzko, S., Lau, S., Lob-Corzilius, T., Nemat, K., Peters, E.M.J., Pizzulli, A., Reese, I., Rolinck-Werninghaus, C., Rouw, E., Schaub, B., Schmidt, S., Steiß, J.O., Striegel, A.K., Szépfalusi, Z., Schlembach, D., Spindler, T., Taube, Christian, Trendelenburg, V., Treudler, R., Umpfenbach, U., Vogelberg, C., Wagenmann, M., Weißenborn, A., Werfel, T., Worm, M., Sitter, H., Hamelmann, Eckard, Hübner, Inga-Marie, Koletzko, Berthold V., Peters, Eva M.J., Steiß, Jens-Oliver, and Striegel, Anne Kathrin

Subjects
Medizin
Abstract

Hintergrund: Die anhaltend hohe Prävalenz allergischer Erkrankungen in westlichen Industrienationen und die eingeschränkten Möglichkeiten einer kausalen Therapie machen eine evidenzbasierte Primärprävention notwendig. Methoden: Die Empfehlungen der in letzter Fassung 2014 veröffentlichten S3-Leitlinie Allergieprävention wurden auf der Basis einer aktuellen systematischen Literatursuche überarbeitet und konsentiert. Die Evidenzsuche erfolgte für den Zeitraum 06/2013 – 11/2020 in den elektronischen Datenbanken Cochrane und MEDLINE, sowie in den Referenzlisten von aktuellen Übersichtsarbeiten und durch Hinweise von Experten. Die aufgefundene Literatur wurde in zwei Filterprozessen zunächst nach Titel und Zusammenfassung und die verbliebenen Arbeiten im Volltext auf Relevanz hin überprüft. Die danach eingeschlossenen Studien wurden nach Evidenzgrade geordnet und die Studienqualität i.S. des Verzerrungspotenzials (niedrig/hoch) angegeben. Die überarbeiteten Empfehlungen wurden unter Beteiligung von Vertretern der relevanten Fachgesellschaften und (Selbsthilfe-)Organisationen formal abgestimmt und konsentiert (nominaler Gruppenprozess). Von 5.681 Treffern wurden 286 Studien eingeschlossen und bewertet. Ergebnisse: Einen wichtigen Stellenwert in der aktualisierten Leitlinie nehmen wieder Empfehlungen zur Ernährung der Mutter während der Schwangerschaft und Stillzeit sowie des Säuglings in den ersten Lebensmonaten ein: Dabei wurden viele der bisherigen Empfehlungen durch die aktuelle Datenlage bestätigt. Präzisiert wurde, dass für den Zeitraum der ersten 4 – 6 Monate nach Geburt nach Möglichkeit ausschließlich gestillt werden soll und auch mit Einführung von Beikost weitergestillt werden soll. Neu ist die Empfehlung, dass eine Zufütterung von kuhmilchbasierter Formulanahrung in den ersten Lebenstagen bei Stillwunsch der Mutter vermieden werden sollte. Ferner wurde festgestellt, dass die Evidenz für eine klare positive Empfehlung für hydrolysierte Säuglingsnahrung bei nicht gestillten Risikokindern aktuell nicht mehr ausreicht. Aktuell wird daher empfohlen zu prüfen, ob bis zur Einführung von Beikost eine Säuglingsanfangsnahrung mit in Studien zur Allergieprävention nachgewiesener Wirksamkeit verfügbar ist. Schließlich wurden auf Basis der EAACI-Leitlinie zur Prävention der Hühnereiallergie die Empfehlung ausgesprochen, durcherhitztes (zum Beispiel verbackenes oder hartgekochtes), aber nicht „rohes“ Hühnerei (auch kein Rührei) mit der Beikost einzuführen und regelmäßig weiter zu geben. Die Empfehlung zur Einführung von Erdnuss in der Beikost wurde für den deutschsprachigen Raum zurückhaltend formuliert: In Familien mit bereits bestehendem regelmäßigem Erdnusskonsum kann zur Prävention einer Erdnussallergie bei Säuglingen mit atopischer Dermatitis die regelmäßige Gabe von erdnusshaltigen Nahrungsmitteln in altersgerechter Form (zum Beispiel Erdnussbutter) mit der Beikost erwogen werden. Vor der Einführung muss insbesondere bei Säuglingen mit moderater bis schwerer AD eine klinisch relevante Erdnussallergie ausgeschlossen werden. Für eine allergiepräventive Wirksamkeit von Präbiotika oder Probiotika, Vitamin D oder anderen Vitaminen in Form von Präparaten fehlt weiterhin ausreichende Evidenz, sodass in der aktuellen Leitlinie erstmals Empfehlungen gegen deren Supplementierung verabschiedet wurden. Die Biodiversität spielt für die Entwicklung einer immunologischen Toleranz gegenüber Umwelt- und Nahrungsmittelallergenen eine wichtige Rolle: So gibt es deutliche Hinweise darauf, dass das Aufwachsen auf dem Bauernhof mit einem geringeren Risiko für die Entwicklung von Asthma und allergischen Erkrankungen assoziiert ist. Dies wird mit einer frühzeitigen unspezifischen Immunstimulation unter anderem durch die größere mikrobielle Biodiversität des Hausstaubs in diesem Lebensraum in Verbindung gebracht. Dieser Aspekt spiegelt sich auch in den Empfehlungen zur Tierhaltung wider, zu der eine differenzierte Stellungnahme erfolgte: In Familien ohne erkennbares erhöhtes Allergierisiko soll die Haustierhaltung mit Katzen oder Hunden nicht generell eingeschränkt werden. Familien mit erhöhtem Allergierisiko (d. h. Vater, Mutter oder Geschwisterkind sind von einer atopischen Erkrankung betroffen) oder bei Kindern mit bereits bestehender atopischer Dermatitis sollten eine Katze nicht neu anschaffen – im Gegensatz dazu sollte von einer Hundehaltung jedoch nicht abgeraten werden. Interventionen zur Reduktion der Exposition gegenüber Hausstaubmilbenallergenen im Haushalt, zum Beispiel die Verwendung milbenallergendichter Matratzenüberzüge („encasings“), sollten nicht mit dem Ziel einer primären Allergieprävention erfolgen. Kinder, die durch einen Kaiserschnitt geboren wurden, haben ein geringfügig erhöhtes Asthmarisiko – dies soll bei der Beratung zum Geburtsmodus außerhalb von Notfallsituationen berücksichtigt werden. Auch aktuelle Arbeiten stützen die Empfehlungen zu Luftschadstoffen: Die aktive und passive Exposition gegenüber Tabakrauch erhöhen das Allergierisiko und sind deshalb zu vermeiden. Die Exposition gegenüber Stickoxiden, Ozon und Feinstaub der Partikelgröße < 2,5 Mikrometer (PM 2,5) ist mit einem erhöhten Risiko, besonders für Asthma, verbunden. Daher sollte die Exposition gegenüber Emissionen gegenüber Stickoxiden, Ozon und Feinstaub (PM 2,5) gering gehalten werden. Die Autor/-innen dieser Leitlinie sprechen sich einhellig für den Erlass entsprechender Verordnungen zur Minimierung dieser Luftschadstoffe aus. Es gibt keine Belege, dass Impfungen das Allergierisiko erhöhen, umgekehrt aber Hinweise, dass Impfungen das Allergierisiko senken können. Alle Kinder, auch Risikokinder, sollen auch aus Gründen der Allergieprävention nach den aktuellen Empfehlungen der ­STIKO geimpft werden. Schlussfolgerung: Die Konsentierung von Empfehlungen in dieser Leitlinie beruht auf einer umfangreichen Evidenzgrundlage. Die Aktualisierung der Leitlinie ermöglicht evidenzbasierte und aktuelle Empfehlungen zur Prävention allergischer Erkrankungen.

Published
2022

38. Climate change and its association with expansion of vectors and vector-borne diseases in the Hindu Kush Himalayan region: A systematic synthesis of the literature

Author

Dhimal, M, Kramer, IM, Phuyal, P, Budhathoki, SS, Hartke, J, Ahrens, B, Kuch, U, Groneberg, DA, Nepal, S, Qi-Yong, L, Cun-Rui, H, Cissé, G, Ebi, KL, Klingelhöfer, D, and Müller, R

Abstract

Observed weather and projected climate change suggest increases in the transmission of vector-borne diseases (VBDs) in the Hindu Kush Himalayan (HKH) region. In this study, we systematically explore the literature for empiric associations between the climate variables and specific mosquito-borne diseases and their vectors in the Himalaya Hindukush region. We conducted a systematic synthesis of the published literature on weather variables and VBDs in the HKH region to 8th December 2020. The majority of studies show significant positive associations of vector-borne diseases with climatic factors such as temperature, precipitation, relative humidity, etc. This systematic review allowed us to identify the most significant variables to be considered for evidence-based trend estimates of the effects of climate change on VBDs and their vectors in HKH region and set this evidence in to the context of climate change trend and with the observed expansion of VBDs and disease vector in the HKH region. The geographic range of vector-borne diseases expanded into previously considered non-endemic areas of highlands (mountains) in the HKH region. Based on scarce, but clear evidence of positive relationship of most climate variables and VBDs and the trend of climatic changes, we strongly recommend an expansion of vector control and surveillance programmes in previously considered non-endemic areas of the HKH region.

Published
2021

42. Climate change and its association with the expansion of vectors and vector-borne diseases in the Hindu Kush Himalayan region: a systematic synthesis of the literature

Author

Dhimal, M., Kramer, I. M., Phuyal, P., Budhathoki, S. S., Hartke, J., Ahrens, B., Kuch, U., Gronenberg, D. A., Nepal, S., Liu, Q., Huang, C., Cissé, G., Ebi, K. L., Klingelhöfer, D., and Müller, R.

Subjects
Dengue, Social sciences (General), H1-99, Chemistry, Himalayas, Meteorology. Climatology, Physics, High altitude, Chikungunya, QC851-999, Leishmaniasis, Biology, Filariasis
Abstract

Observed weather and projected climate change suggest an increase in the transmission of vector-borne diseases (VBDs) in the Hindu Kush Himalayan (HKH) region. In this study, we systematically explore the literature for empiric associations between the climate variables and specific VBDs and their vectors in the HKH region. We conducted a systematic synthesis of the published literature on climate variables, VBDs and vectors in the HKH region until the 8th of December 2020. The majority of studies show significant positive associations of VBDs with climatic factors, such as temperature, precipitation, relative humidity, etc. This systematic review allowed us to identify the most significant variables to be considered for evidence-based trend estimates of the effects of climate change on VBDs and their vectors in the HKH region. This evidence-based trend was set into the context of climate change as well as the observed expansion of VBDs and disease vectors in the HKH region. The geographic range of VBDs expanded into previously considered non-endemic areas of highlands (mountains) in the HKH region. Based on scarce, but clear evidence of a positive relationship of most climate variables and VBDs and the observed climatic changes, we strongly recommend an expansion of vector control and surveillance programmes in areas of the HKH region that were previously considered to be non-endemic.

Published
2021
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