Errors and uncertainties introduced by a regional climate model in climate impact assessments: example of crop yield simulations in West Africa

16 pagesInternational audienceThe challenge of estimating the potential impacts of climate change has led to an increasing use of dynamical downscaling to produce fine spatial-scale climate projections for impact assessments. In this work, we analyze if and to what extent the bias in the simulated crop yield can be reduced by using the Weather Research and Forecasting (WRF) regional climate model to downscale ERA-Interim (European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis) rainfall and radiation data. Then, we evaluate the uncertainties resulting from both the choice of the physical parameterizations of the WRF model and its internal variability. Impact assessments were performed at two sites in Sub-Saharan Africa and by using two crop models to simulate Niger pearl millet and Benin maize yields. We find that the use of the WRF model to downscale ERA-Interim climate data generally reduces the bias in the simulated crop yield, yet this reduction in bias strongly depends on the choices in the model setup. Among the physical parameterizations considered, we show that the choice of the land surface model (LSM) is of primary importance. When there is no coupling with a LSM, or when the LSM is too simplistic, the simulated precipitation and then the simulated yield are null, or respectively very low; therefore, coupling with a LSM is necessary. The convective scheme is the second most influential scheme for yield simulation, followed by the shortwave radiation scheme. The uncertainties related to the internal variability of the WRF model are also significant and reach up to 30% of the simulated yields. These results suggest that regional models need to be used more carefully in order to improve the reliability of impact assessments

iFGF-23-ELISA versus cFGF-23-ELISA als kardiovaskuläre Prädiktoren bei chronischer Nierenerkrankung

Patienten mit chronischer Nierenerkrankung (chronic kidney disease, CKD) haben gegenüber der nierengesunden Population ein substantiell erhöhtes kardiovaskuläres Risiko, welches sich nicht allein durch „traditionelle“ Risikofaktoren erklären lässt. Als „nicht-traditioneller“ Risikofaktor konnte im Rahmen des Kalzium - Phosphat - Stoffwechsels (CKD - MBD, „Chronic Kidney Disease - Mineral Bone Disorder“) der Fibroblasten-Wachstumsfaktor 23 (Fibroblast-Growth-Factor-23, FGF-23) als ein von der Nierenfunktion unabhängiger Prädiktor kardiovaskulärer, atherosklerotischer kardiovaskulärer Ereignisse (ASCVD) und kardialer Dekompensation identifiziert werden. Zur Messung von FGF-23 stehen zwei ELISAs zur Verfügung. Der erste ELISA („intact FGF-23“, iFGF-23) erfasst ausschließlich das aktive (intakte) Hormon, wohingegen der zweite Assay („c-terminal FGF-23“, cFGF-23) sowohl das intakte Hormon als auch inaktive, C-terminale Fragmente misst. Bis heute wird epidemiologisch bei der Messung von FGF-23 zumeist der cFGF-23-ELISA genutzt, während es kaum Daten zur prognostischen Bedeutung des iFGF-23-ELISA gibt. Wir überprüfen in dieser Arbeit die Hypothesen, dass mit zunehmender Nierenfunktionsverschlechterung vor allem aktives FGF-23 akkumuliert, der iFGF-23-ELISA also stärker mit der glomerulären Filtrationsrate (GFR) korreliert als der cFGF-23-ELISA. Da in der Vergangenheit ein direkt toxischer Effekt von FGF-23 in Betracht gezogen wurde, müssten iFGF-23-Messungen stärker mit ASCVD und stationären Aufnahmen aufgrund kardialer Dekompensation korrelieren. Wir überprüfen also weiterhin die Hypothese, ob der iFGF-23-ELISA im Vergleich zum cFGF-23-ELISA ein besserer Prädiktor für unsere vordefinierten Endpunkte ist. Methoden: Zwischen 2008 und 2014 wurden 544 chronisch nierenkranke Patienten der „Kidney Disease: Improving Global Outcomes“ (KDIGO) GFR-Kategorie G2 - G4 in die fortlaufende CARE FOR HOMe-Studie eingeschlossen. Die geschätzte glomeruläre Filtrationsrate („estimated glomerular filtration rate“, eGFR) wurde mittels MDRD-Formel berechnet. Mit konventionellen Labormethoden wurden bei Studieneinschluss kardiovaskuläre Risikofaktoren sowie etablierte Parameter der Nierenfunktion und des Calcium-Phosphat-Metabolismus (Chronic Kidney Disease - Mineral Bone Disorder, CKD-MBD) bestimmt. Die iFGF-23- und cFGF-23-Messungen erfolgten mittels ELISA der zweiten Generation (Fa Immutopics, USA) aus zum Zeitpunkt des Studieneinschlusses asservierten Proben. Der primäre renale Endpunkt ist in dieser Arbeit definiert als eine Reduktion der eGFR um mehr als 50 % im Vergleich zum Studieneinschluss, Beginn eines Nierenersatzverfahrens oder Tod jedweder Genese. Der sekundäre renale Endpunkt umfasst den Beginn eines Nierenersatzverfahrens oder eine dauerhafte Reduktion der eGFR um mehr als 50 %. Der primäre atherosklerotische kardiovaskuläre Endpunkt wurde definiert als koronararterielle Intervention (PTCA / Stent / Bypassoperation), Myokardinfarkt, peripher-arterielle Revaskularisation (PTA / Stent / Bypassoperation), zerebrovaskuläre Revaskularisation (Carotis-Thrombendarteriektomie / -Stent), Apoplex mit klinischen Symptomen, welche mindestens 24 Stunden persistierten, eine nichttraumatische Amputation proximal des Fußgrundgelenkes oder Todesfälle jedweder Genese. Der sekundäre atherosklerotische kardiovaskuläre Endpunkt ersetzte Todesfälle jedweder Genese durch kardiovaskuläre Todesfälle. Weiterhin definieren wir zwei weitere kardiale Endpunkte: Zum einen den kombinierten Endpunkt stationäre Aufnahme aufgrund akuter kardialer Dekompensation oder Tod jedweder Genese; zum anderen stationäre Aufnahme aufgrund akuter kardialer Dekompensation ohne Todesfälle. Dabei lag eine akute kardiale Dekompensation vor, wenn diese aufgrund von Symptomen (progressive Dyspnoe) und klinischen (periphere Ödeme, pulmonale Rasselgeräusche) oder radiologischen (Kardiomegalie, pulmonales Ödem, Pleuraerguss) Zeichen einer akuten kardialen Dekompensation erfolgte. Ergebnisse: In unserer Arbeit korrelierten sowohl iFGF-23-Messungen (r = -0,536) als auch cFGF 23 Messungen (r = -0,529) signifikant mit der eGFR, mit Phosphat (iFGF-23 r = 0,376; cFGF-23 r = 0,334), der fraktionellen Phosphatexkretion im Urin (iFGF-23 r = 0,467; cFGF-23 r = 0,408), logarithmiertem NT-proBNP (iFGF-23 r = 0,373; cFGF-23 r = 0,468), PTH (iFGF 23 r = 0,469; cFGF-23 r = 0,425) und der logarithmierten Albuminurie (iFGF-23 r = 0,287; cFGF-23 r = 0,302). Alle oben aufgeführten Korrelationen waren mit p < 0,001 statistisch signifikant. Visuell sind die cFGF-23-Messungen im Box-Plot jedoch stärker mit der GFR assoziiert als die iFGF-23-Messungen. Während einer durchschnittlichen Nachbeobachtungszeit von 5,07 ± 2,15 Jahren erreichten 147 Patienten den primären renalen Endpunkt, 159 Patienten den primären atherosklerotischen kardiovaskulären Endpunkt und 131 Patienten den kombinierten Endpunkt einer stationären Aufnahme aufgrund akuter kardialer Dekompensation oder Todesfällen jedweder Genese. Patienten mit höheren FGF-23-Werten zeigten eine signifikant schlechtere Prognose bezüglich der renalen Progression, ASCVD und kardialer Dekompensation. FGF-23 war dabei stärker mit kardialer Dekompensation assoziiert als mit ASCVD. cFGF-23-Messungen, nicht jedoch iFGF 23-Messungen, blieben nach Korrektur für eGFR (und anschließend für Alter, Geschlecht, Diabetes Mellitus, iFGF-23-Messungen und Phosphat) ein unabhängiger Prädiktor für kardiale Dekompensation. Diskussion: Entgegen unserer Annahme waren cFGF-23-Messungen stärker mit dem primären renalen Endpunkt assoziiert als iFGF-23-Messungen. Außerdem waren cFGF-23-Messungen stärker mit dem primären atherosklerotischen kardiovaskulären Endpunkt und mit dem kombinierten Endpunkt von stationärer Aufnahme aufgrund akuter kardialer Dekompensation und Tod jedweder Genese assoziiert als iFGF-23-Messungen. Da cFGF-23-Messungen weniger spezifisch das aktive Hormon reflektieren als iFGF 23 Messungen, sprechen unsere Daten insgesamt gegen einen direkt toxischen Effekt von aktivem FGF-23, sodass FGF-23-senkende Maßnahmen bei chronisch Nierenkranken als prognoseverbessernde Therapieoption überdacht werden sollten.Patients suffering from chronic kidney disease (CKD) have a tremendously higher risk of cardiovascular events than individuals with intact renal function. Beyond classical cardiovascular risk factors, chronic kidney disease – mineral and bone disorder (CKD - MBD) may contribute to this high cardiovascular risk. CKD - MBD comprises an increased expression of the phosphaturic fibroblast growth factor 23 (FGF-23). In several cohort studies, plasma levels of FGF-23 were associated with markedly increased risk of cardiovascular events. Of note, two different ELISAs for FGF-23 measurement are available: the cFGF-23-ELISA, which measures both biologically active full-length intact FGF-23 and its inactive c-terminal fragments, and the iFGF-23-ELISA, which only measures biologically active full-length FGF-23. Until now, most large cohort studies have used cFGF-23-ELISAs for measuring FGF-23 as outcome predictor, while data on iFGF-23-ELISA remain sparse. The purpose of this study was firstly to analyze the degree to which iFGF-23-measurements accumulates across the spectrum of CKD. It has been claimed that elevated FGF-23-levels directly contribute to high rates of left ventricular hypertrophy (LVH) and mortality. We therefore analyzed whether iFGF-23-ELISA outperforms cFGF-23-ELISA as a predictor of cardiovascular events and heart failure. Methods: Among 544 patients of our ongoing CARE FOR HOMe-study, we measured cFGF-23-measurements and iFGF-23-measurements from plasma samples stored at study inclusion (between 2008 and 2014). The MDRD equation was applied for estimation of glomerular filtration rate (eGFR); all patients had CKD KDIGO GFR stages G2 - G4 at study inclusion. We defined the following endpoints: firstly, the primary renal endpoint as the occurrence of sustained eGFR drop ≥ 50 % of baseline, need for renal replacement therapy or death of any cause, the secondary renal endpoint as the occurrence of sustained eGFR drop ≥ 50 % of baseline or need for renal replacement therapy. Next, we defined the primary atherosclerotic cardiovascular endpoint as the occurrence of coronary revascularization (PTCA / stent / bypass), myocardial infarction, peripheral arterial revascularization (PTCA / stent / bypass), carotid revascularization (stent / thrombendarterectomy), stroke with symptoms that last at least 24 hours, non-traumatic amputation proximal of the ankle joint or death of any cause. The secondary atherosclerotic cardiovascular endpoint substituted death of any cause for cardiovascular death instead. Finally we assessed two additional cardiac endpoints: firstly the combined endpoint of acute cardiac decompensation (defined as admission for a clinical syndrome involving symptoms (progressive dyspnoea) in conjunction with clinical (peripheral oedema, pulmonary rales) or radiological (cardiomegaly, pulmonary oedema, pleural effusions) signs of heart failure) and death of any cause, and secondly the occurrence of acute cardiac decompensation alone. Results: In our studies we found strong correlations between iFGF-23-measurements and eGFR (r = -0.536) and cFGF-23-measurements and eGFR (r = -0.529) as well as significant correlations between FGF-23 and phosphate (iFGF-23 r = 0.376; cFGF-23 r = 0.334), fractional phosphate excretion in urine (iFGF-23 r = 0.467; cFGF-23 r = 0.408), log NT-proBNP (iFGF-23 r = 0.373; cFGF-23 r = 0.468), PTH (iFGF-23 r = 0.469; cFGF-23 r = 0.425) and log-transformed albuminuria (iFGF-23 r = 0.287; cFGF-23 r = 0.302). All these correlations were statistically significant (p < 0.001). Visually cFGF-23-ELISA appears to be even stronger correlated with eGFR than iFGF-23-ELISA. During a mean follow-up of 5.07 ± 2.15 years 147 patients reached the primary renal endpoint, 159 patients reached the primary atherosclerotic cardiovascular endpoint and 131 patients suffered from cardiac decompensation or died. Patients with higher FGF-23 were more likely to reach the predefined endpoints. Moreover FGF-23 was stronger associated with cardiac decompensation than with ASCVD. cFGF-23-measurements, but not iFGF-23-measurements, remained an independent outcome predictor for heart failure after adjustment for eGFR (and subsequently for age, gender, diabetes mellitus, iFGF-23-ELISA and plasma phosphorus). Discussion: Against our hypothesis cFGF-23-measurements were more strongly correlated with eGFR than iFGF-23-measurements. Additionally, we found that cFGF-23-ELISA outperformed iFGF-23-ELISA as a predictor of not only renal events, but also atherosclerotic cardiovascular events and acute cardiac decompensation. As cFGF-23-measurements reflect FGF-23 activity less specifically than iFGF-23-measurements, our data suggest against a direct adverse myocardial effect of FGF-23 in patients with CKD. Conclusively, the prognostic benefit of FGF-23 lowering in CKD patients seems questionable

“Forged in Crisis?” Assessing the EU’s Evolving Actorness in Energy Security in Light of Energy Supply Crises

This thesis’s purpose is two-fold. First, the primary purpose of this thesis is to explore the EU’s evolving actorness in energy security, seeking to answer how we can understand the main factors that have led to the EU acquiring actorness in energy security. In this context, the thesis builds on the theoretical framework of actorness, informed by the two criteria of decision-making power and capabilities. By applying the method of process-tracing and primarily looking at empirical material from the Commission, the analysis reveals that crises in energy supply are the main driving force behind EU actorness in energy security. Second, the study explores how strategic autonomy is manifested in the EU’s ambitions regarding energy security. The analysis finds that the concept is reflected in the EU’s plan to end its overreliance on Russian energy imports with the help of diversifying, investing in renewables, reducing demand, and developing storage capacity.Master of Art

The Footprint of Things: A hybrid approach towards the collection, storage and distribution of life cycle inventory data

Life cycle assessment is a well-established methodology for assessing the environmental impacts of products and services. Unfortunately, an essential part of this life cycle assessment method, collecting inventory data, is extremely time consuming. The quality of manually conducted LCA studies is often limited by uncertainty in the inventory data or narrow scope. Past attempts to overcome these challenges through automation of data collection utilizing the Internet of Things have relied on fully centralized architectures. The drawback of a central repository is the complex coordination between all involved actors in supply chains of products and services. This paper proposes an alternative hybrid approach combining a primary distributed system supplemented with a central repository reducing the need for coordination. This hybrid approach is named "the Footprint of Things". We present a system design that embeds the automatic reporting of life cycle inventory data, such as energy and material flows, into all product components involved in a service delivery. The major strength of our novel system design, among others, is its capacity for real-time and more precise impact calculation of ICT services

Ökologische Nachhaltigkeit in der digitalen Produktion

Die industrielle Produktion durchläuft aktuell einen erheblichen Transformationsprozess, ermöglicht durch die rasante Entwicklung der Informations- und Kommunikationstechnologien. Welche Rolle spielt die Industrie 4.0. für eine sozial-ökologische Entwicklung

Immunize the Public against Disinformation Campaigns: Developing a Framework for Analyzing the Macrosocial Effects of Prebunking Interventions

The rapid spread of disinformation through online environments challenges the development of suitable solution approaches. The scientific evaluation of various intervention strategies shows that until now, no magic bullet has been found that can overcome the problem in all relevant dimensions. Due to the effective impact at the individual level, research highlights the potential of prebunking interventions as a promising coping approach to achieve herd immunity to disinformation on a macrosocial level. Inside a detection system, prebunking interventions can curb the spread of disinformation campaigns early. The identification of turning points at which preventive intervention in (dis)information diffusion is necessary for implementation first requires an exploration of the effectiveness of the diffusion of prebunking interventions in social networks. We present a framework for analyzing the macrosocial effects and patterns of the effectiveness of prebunking interventions in the context of three different attack scenarios of stereotypical disinformation campaigns using agent-based modeling

Immunize the Public against Disinformation Campaigns: Developing a Framework for Analyzing the Macrosocial Effects of Prebunking Interventions

The rapid spread of disinformation through online environments challenges the development of suitable solution approaches. The scientific evaluation of various intervention strategies shows that until now, no magic bullet has been found that can overcome the problem in all relevant dimensions. Due to the effective impact at the individual level, research highlights the potential of prebunking interventions as a promising coping approach to achieve herd immunity to disinformation on a macrosocial level. Inside a detection system, prebunking interventions can curb the spread of disinformation campaigns early. The identification of turning points at which preventive intervention in (dis)information diffusion is necessary for implementation first requires an exploration of the effectiveness of the diffusion of prebunking interventions in social networks. We present a framework for analyzing the macrosocial effects and patterns of the effectiveness of prebunking interventions in the context of three different attack scenarios of stereotypical disinformation campaigns using agent-based modeling

Digitalization and the Decoupling Debate: Can ICT Help to Reduce Environmental Impacts While the Economy Keeps Growing?

Digitalization can increase resource and energy productivities. However, the production and usage of information and communication technologies (ICTs) require materials and energy, and the application of ICTs fosters economic growth. This paper examines whether digitalization helps or hinders an absolute decoupling of environmental throughput from economic growth. The paper combines the literature on “green IT” and “ICT for green” with studies on decoupling, i.e., the relationship between economic growth, technological change, and environmental throughput. The paper identifies several strains of the decoupling debate and connects them to the environmental implications of digitalization. We focus on the relation between digitalization and (1) the question of finite non-renewable energies, (2) the environmental Kuznets curve, (3) the role of energy consumption for economic growth, (4) efficiency improvements vis-à-vis rebound effects, and (5) the role of general purpose technologies for resource and energy demand. We find that the empirical basis regarding digitalization’s relation to these four aspects is still weak and hence, further research is needed. Comparing the mitigating and the aggravating impacts of digitalization, we conclude that a more active political and societal shaping of the process of digitalization is needed to make ICT work for global environmental sustainability.TU Berlin, Open-Access-Mittel – 2020BMBF, 01UU1607B, Zwischen Rebound-Risiken und Suffizienz-Chancen: Herausforderungen der Entkopplung von Umweltverbrauch und Wirtschaftswachstum am Beispiel der Digitalisierung von Dienstleistungen - Teilprojekt 2: Wirtschaftspolitik & Konsu

The Four Dimensions of the Foreign Fighter Threat: Making Sense of an Evolving Phenomenon

In light of Islamic State’s decreasing military power and growing emphasis on a decentralised operational strategy, the threat posed by foreign fighters is shifting, with some aspects becoming less threatening as others become more salient. This Policy Brief provides a concise outline of four main threats related to the issue of foreign fighters with the aim of clarifying the parameters of the phenomenon in its current manifestation: the travel of foreign fighters, their return to their countries of residence, the threat posed by lone actors and sympathisers who carry out attacks at home, and finally, an increasing polarisation of society. It is argued that policymakers need to take into account the second and third order effects that targeting one of these aspects may have on the others in order to effectively counter a multi-dimensional phenomenon