31325 research outputs found
Sort by
Bringing it all together: science priorities for improved understanding of Earth system change and to support international climate policy
No full textWe review how the international modelling community, encompassing integrated assessment models, global and regional Earth system and climate models, and impact models, has worked together over the past few decades to advance understanding of Earth system change and its impacts on society and the environment and thereby support international climate policy. We go on to recommend a number of priority research areas for the coming decade, a timescale that encompasses a number of newly starting international modelling activities, as well as the IPCC Seventh Assessment Report (AR7) and the second UNFCCC Global Stocktake. Progress in these priority areas will significantly advance our understanding of Earth system change and its impacts, increasing the quality and utility of science support to climate policy.We emphasize the need for continued improvement in our understanding of, and ability to simulate, the coupled Earth system and the impacts of Earth system change. There is an urgent need to investigate plausible pathways and emission scenarios that realize the Paris climate targets – for example, pathways that overshoot 1.5 or 2 °C global warming, before returning to these levels at some later date. Earth system models need to be capable of thoroughly assessing such warming overshoots – in particular, the efficacy of mitigation measures, such as negative CO2 emissions, in reducing atmospheric CO2 and driving global cooling. An improved assessment of the long-term consequences of stabilizing climate at 1.5 or 2 °C above pre-industrial temperatures is also required. We recommend Earth system models run overshoot scenarios in CO2-emission mode to more fully represent coupled climate–carbon-cycle feedbacks and, wherever possible, interactively simulate other key Earth system phenomena at risk of rapid change during overshoot. Regional downscaling and impact models should use forcing data from these simulations, so impact and regional climate projections cover a more complete range of potential responses to a warming overshoot. An accurate simulation of the observed, historical record remains a fundamental requirement of models, as does accurate simulation of key metrics, such as the effective climate sensitivity and the transient climate response to cumulative carbon emissions. For adaptation, a key demand is improved guidance on potential changes in climate extremes and the modes of variability these extremes develop within. Such improvements will most likely be realized through a combination of increased model resolution, improvement of key model parameterizations, and enhanced representation of important Earth system processes, combined with targeted use of new artificial intelligence (AI) and machine learning (ML) techniques. We propose a deeper collaboration across such efforts over the coming decade.With respect to sampling future uncertainty, increased collaboration between approaches that emphasize large model ensembles and those focussed on statistical emulation is required. We recommend an increased focus on high-impact–low-likelihood (HILL) outcomes – in particular, the risk and consequences of exceeding critical tipping points during a warming overshoot and the potential impacts arising from this. For a comprehensive assessment of the impacts of Earth system change, including impacts arising directly as a result of climate mitigation actions, it is important that spatially detailed, disaggregated information used to generate future scenarios in integrated assessment models be available for use in impact models. Conversely, there is a need to develop methods that enable potential societal responses to projected Earth system change to be incorporated into scenario development.The new models, simulations, data, and scientific advances proposed in this article will not be possible without long-term development and maintenance of a robust, globally connected infrastructure ecosystem. This system must be easily accessible and useable by modelling communities across the world, allowing the global research community to be fully engaged in developing and delivering new scientific knowledge to support international climate policy.European CommissionMet OfficeEuropean Cooperation in Science and TechnologyPeer Reviewe
A cross-regional comparative analysis
No full textThe article processing charge was funded by the Open Access Publication Fund of Humboldt-Universität zu Berlin.Bioeconomy policies aim at fostering economic growth while solving the sustainability challenges of the fossil-based economy. However, these policies do little to discuss the resilience challenges of bioeconomies and the bio-based production systems on which they rest. Specifically, the environmental stresses that are likely to threaten the delivery of the bioeconomy's desired functions are barely addressed. This paper aims to understand why the salience of environmental resilience challenges is low in bioeconomy strategies. We conduct an exploratory comparative analysis of the policy design processes of six countries - Malaysia, South Africa, the United Kingdom, Ireland, Italy and Germany - building on expert interviews and a conceptual approach that emphasizes the importance of the policy design space. Our findings suggest that key factors in explaining the low salience of environmental resilience challenges are the predominantly economic motivation among leading authorities and the under-representation of environmental actors across policy design spaces.Peer Reviewe
Die Rolle von Unterhaltung bei den Angeboten zur Leseförderung in Öffentlichen Bibliotheken
No full textDiese Veröffentlichung geht zurück auf eine Masterarbeit im weiterbildenden Masterstudiengang im Fernstudium Bibliotheks- und Informationswissenschaft (Library and Information Science, M. A. (LIS)) an der Humboldt-Universität zu Berlin aus dem Jahr 2024.Der Aufbau und Erhalt der Lesemotivation und Lesekompetenz ist als gesamtgesellschaftliche Aufgabe zu verstehen. Neben Elternhaus und Schule sind Bibliotheken eine besonders wichtige Instanz der Leseförderung. Ihnen kommt die Aufgabe zu, passendes Lesematerial für eine Vielzahl von Interessen und Altersstufen bereitszustellen, ohne von den finanziellen Ressourcen der Familien abhängig zu sein. Öffentliche Bibliotheken bieten eine breite Palette an unterhaltsamen Angeboten zur Leseförderung an, die verschiedene Medien und Formate umfassen. In der vorliegenden qualitativen Forschungsarbeit wird untersucht, welche Rolle die Unterhaltung bei diesen Angeboten spielt. Unterhaltung und Bildung sind dabei keine Gegensätze, sondern können sich gegenseitig ergänzen und bereichern
Raum- und Akteur*innenkonstruktion am Beispiel des sogenannten "Kurfürstendamm-Krawalls" am 12. September 1931
No full textPeer Reviewe
Electrochemical Surface Plasmon Resonance Sensing using a van der Waals Heterostructure
No full textThe article processing charge was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – 491192747 and the Open Access Publication Fund of Humboldt-Universität zu Berlin.Coupling surface plasmon resonance (SPR) sensing with electrochemistry (EC) is a promising analytical strategy to obtain information about interfacial phenomena in heterogeneous reactions. Typical EC-SPR sensors utilize a metal film both as the plasmonic material and as the working electrode. In this configuration, the eigenmodulation of the plasmonic properties of the metal film under applied potential results in a background signal, which hampers the unambiguous interpretation of the sensor response due to redox reactions. Here, a new strategy is presented to overcome this disadvantage by using a van der Waals heterostructure (vdW-HS) as the working electrode. The vdW-HS comprises of a graphene / hexagonal boron nitride (hBN) stack on a gold film of a standard SPR sensor. It is shown here that the background signal is completely suppressed enabling the unambiguous analysis of SPR sensor response due to electrochemical reactions. It is further observed that the potential dependent plasmonic signals are not just a reproduction of the electrochemical current and subtle differences can be traced back to the diffusive nature of the redox active species. Finally, it is demonstrated that EC-SPR can be used as a complementary method to distinguish if the electrochemical response is mainly surface-bound or due to diffusion.Peer Reviewe
Unveiling the Spectroscopic Signatures of Poly(3,4-ethylenedioxythiophene) by Controlling Polaron and Bipolaron Concentrations
No full textThe electronic and optical properties of conductive polymers (CPs) are related to the formation of polarons and bipolarons localized along the polymer backbone. Their concentration is affected by the conformational and morphological features of the CPs, making it crucial to understand how they are affected by chain conformation and π-electron delocalization. In this work, we studied the modulation of the concentration of polarons and bipolarons in PEDOT:PSS after post-treatment with hydrazine and H2SO4, which influence the optical and electronic properties. Through a combination of electron spin resonance spectroscopy, UV–vis–NIR spectroscopy, Raman spectroscopy, and conductivity measurements, we evaluate changes in the properties of PEDOT, which are related to the chain conformation and π-electron delocalization within the polymer backbone. We present experimental evidence supporting the recently revised interpretation of the UV–vis–NIR spectrum of PEDOT:PSS, and through a combination of theoretical and experimental analysis, we propose a new interpretation of the Raman spectrum of PEDOT:PSS. Furthermore, we provide the first experimental evidence of the presence of polaron pairs in the triplet state in PEDOT:PSS, which have a spin of S = 1, which were only predicted theoretically up to this point.Deutsche Forschungsgemeinschaft 10.13039/501100001659Consejo Nacional de Humanidades, Ciencias y Tecnolog?as 10.13039/501100003141Einstein Stiftung Berlin 10.13039/501100006188Peer Reviewe
Kötüden daha kötüye mi gidiyor? Şubat 2023 depremleri sonrasında Türkiye'deki Suriyeli mültecilerin refahı
No full textIs translation of: https://doi.org/10.18452/28152 [English]Önemli Noktalar: (1) Türkiye'deki Suriyelilerin depremler öncesindeki sosyal ve ekonomik dezavantajları ve kötü yaşam koşulları, onları depremlerin yıkıcı gücüne karşı özellikle savunmasız hale getirmiştir. (2) Suriyelilerin depreme bağlı kayıp ve hasarlarla başa çıkmak için daha az sosyal, mali ve maddi kaynağa sahip olması, eşitsizlikleri ve kırılganlıkları artırmıştır. (3) Bazı Suriyeliler, mevcut eşitsizlikleri telafi etmeye yardımcı olabilecek sosyal ve ekonomik destek almak yerine, yetersiz yardım nedeniyle ayrımcılık ve ciddi sorunlar yaşadıklarını bildirmiştir.Peer Reviewe
A multi-omics approach to unravel the interaction between heat and drought stress in the Arabidopsis thaliana holobiont
No full textThe impact of combined heat and drought stress was investigated in Arabidopsis thaliana and compared to individual stresses to reveal additive effects and interactions. A combination of plant metabolomics and root and rhizosphere bacterial metabarcoding were used to unravel effects at the plant holobiont level. Hierarchical cluster analysis of metabolomics signatures pointed out two main clusters, one including heat and combined heat and drought, and the second cluster that included the control and drought treatments. Overall, phenylpropanoids and nitrogen-containing compounds, hormones and amino acids showed the highest discriminant potential. A decrease in alpha-diversity of Bacteria was observed upon stress, with stress-dependent differences in bacterial microbiota composition. The shift in beta-diversity highlighted the pivotal enrichment of Proteobacteria , including Rhizobiales , Enterobacteriales and Azospirillales . The results corroborate the concept of stress interaction, where the combined heat and drought stress is not the mere combination of the single stresses. Intriguingly, multi-omics interpretations evidenced a good correlation between root metabolomics and root bacterial microbiota, indicating an orchestrated modulation of the whole holobiont.Peer Reviewe
Serotonin drives aggression and social behaviors of laboratory male mice in a semi-natural environment
No full textAggression is an adaptive social behavior crucial for the stability and prosperity of social groups. When uncontrolled, aggression leads to pathological violence that disrupts group structure and individual wellbeing. The comorbidity of uncontrolled aggression across different psychopathologies makes it a potential endophenotype of mental disorders with the same neurobiological substrates. Serotonin plays a critical role in regulating impulsive and aggressive behaviors. Mice lacking in brain serotonin, due to the ablation of tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme in serotonin synthesis, could serve as a potential model for studying pathological aggression. Home cage monitoring allows for the continuous observation and quantification of social and non-social behaviors in group-housed, freely-moving mice. Using an ethological approach, we investigated the impact of central serotonin ablation on the everyday expression of social and non-social behaviors and their correlations in undisturbed, group-living Tph2 -deficient and wildtype mice. By training a machine learning algorithm on behavioral time series, “allogrooming”, “struggling at feeder”, and “eating” emerged as key behaviors dissociating one genotype from the other. Although Tph2 -deficient mice exhibited characteristics of pathological aggression and reduced communication compared to wildtype animals, they still demonstrated affiliative huddle behaviors to normal levels. Altogether, such a distinct and dynamic phenotype of Tph2 -deficient mice influenced the group's structure and the subsequent development of its hierarchical organization. These aspects were analyzed using social network analysis and the Glicko rating methods. This study demonstrates the importance of the ethological approach for understanding the global impact of pathological aggression on various aspects of life, both at the individual and group levels. Home cage monitoring allows the observation of the natural behaviors of mice in a semi-natural habitat, providing an accurate representation of real-world phenomena and pathological mechanisms. The results of this study provide insights into the neurobiological substrate of pathological aggression and its potential role in complex brain disorders.Peer Reviewe
Analysis and Comparison of Deduplication Strategies in IPFS
No full textIPFS hat in letzter Zeit an Popularität gewonnen, da es das Rückgrat für den Dateiaustausch im dezentralen Web darstellt. Da die Anzahl der auf IPFS ausgetauschten Dateien wächst und sowohl Speicherplatz als auch Netzwerkbandbreite teuer sind, wird die Diskussion über Deduplizierungsstrategien zunehmend dringlicher. Diese Diskussion stützt sich weitgehend auf die Ausführung von Chunking-Algorithmen. Zu diesem Zweck haben wir FastCDC und AE als zwei hochmoderne Chunking-Algorithmen mit Rabin, Buzhash und festgelegtem Chunking verglichen, die in Implementierungen von IPFS weit verbreitet sind. Unsere Analyse umfasst die Bewertung der Rechenleistung, der Deduplizierungsrate bei verschiedenen Datensätzen, der durchschnittlichen Chunk-Größe und der Chunk-Größenverteilung. Wir reproduzieren Ergebnisse aus der bisherigen Literatur und glauben darüber hinaus, die ersten zu sein, die umfassende Ergebnisse für Buzhash sowie für bestimmte Metriken der anderen Chunking-Algorithmen präsentieren. Darüber hinaus führten wir eine Analyse eines empirischen Datensatzes basierend auf Spuren von IPFS durch, die weitere Einblicke in die Datenlandschaft und das Nutzerverhalten auf IPFS liefert. Abschließend schlagen wir eine verbesserte Chunking-Strategie für IPFS vor.IPFS has recently risen in popularity, as it represents the backbone for file sharing in a decentralized web. As the amount of files exchanged on IPFS grows, and both storage and network bandwidth are expensive, the discussion around deduplication strategies becomes pressing. This discussion is largely founded on the execution of chunking algorithms. To this end, we analyzed and compared FastCDC and AE, as two state-ofthe-art chunking algorithms, with Rabin, Buzhash, and fixed-size chunking, which are prevalent in implementations of IPFS. Our analysis includes the evaluation of computational efficiency, deduplication ratio on various datasets, average chunk size and chunk-size distribution. We reproduce results from previous literature, and further believe to be the first to present comprehensive results for Buzhash, as well as for certain metrics of the other chunking algorithms. Furthermore, we conducted an analysis on an empirical dataset based on traces from IPFS, which reveals further insights about the data landscape and user behavior in IPFS. Finally, we propose an improved chunking strategy for IPFS