Refine
Year of publication
Document Type
- Article (20522)
- Doctoral Thesis (3109)
- Postprint (2090)
- Monograph/Edited Volume (1193)
- Other (641)
- Review (583)
- Conference Proceeding (298)
- Preprint (230)
- Part of a Book (218)
- Working Paper (131)
Language
- English (29226) (remove)
Is part of the Bibliography
- yes (29226) (remove)
Keywords
- climate change (173)
- Germany (98)
- machine learning (80)
- diffusion (76)
- German (68)
- Arabidopsis thaliana (65)
- anomalous diffusion (58)
- stars: massive (57)
- Climate change (55)
- Holocene (55)
Institute
- Institut für Physik und Astronomie (4847)
- Institut für Biochemie und Biologie (4667)
- Institut für Geowissenschaften (3286)
- Institut für Chemie (2845)
- Institut für Mathematik (1560)
- Department Psychologie (1396)
- Institut für Ernährungswissenschaft (1013)
- Department Linguistik (915)
- Wirtschaftswissenschaften (826)
- Institut für Informatik und Computational Science (793)
Digitalization, as well as sustainability, are gaining increased relevance and have attracted significant attention in research and practice. However, the research already published about this topic examining digitalization in the retail sector does not consider the acceptance of related innovations, nor their impact on sustainability. Therefore, this article critically analyzes the acceptance of customers towards digital technologies in fashion stores as well as their impact on sustainability in the textile industry. The comprehensive analysis of the literature and the current state of research provide the basis of this paper. Theoretical models, such as the Technology-Acceptance-Model (TAM) and the Unified Theory of Acceptance and Use of Technology 2 (UTAUT 2) enable the evaluation of expectations and acceptance, as well as the assessment of possible inhibitory factors for the subsequent descriptive and statistical examination of the acceptance of digital technologies in fashion stores. The research on this subject was examined in a quantitative way. The key findings show that customers do accept digital technologies in fashion stores. The final part of this contribution describes the innovative Digitalization 4 Sustainability Framework which shows that digital technologies at the point of sale (PoS) in fashion stores could have a positive impact on sustainability. Overall, this paper shows that it is particularly important for fashion stores to concentrate on their individual strengths and customer needs as well as to indicate a more sustainable way by using digital technologies, in order to achieve added value for the customers and to set themselves apart from the competition while designing a more sustainable future. Moreover, fashion stores should make it a point of their honor to harness the power of digitalization for sake of sustainability and economic value creation.
Due to anthropogenic greenhouse gas emissions, Earth’s average surface temperature is steadily increasing. As a consequence, many weather extremes are likely to become more frequent and intense. This poses a threat to natural and human systems, with local impacts capable of destroying exposed assets and infrastructure, and disrupting economic and societal activity. Yet, these effects are not locally confined to the directly affected regions, as they can trigger indirect economic repercussions through loss propagation along supply chains. As a result, local extremes yield a potentially global economic response. To build economic resilience and design effective adaptation measures that mitigate adverse socio-economic impacts of ongoing climate change, it is crucial to gain a comprehensive understanding of indirect impacts and the underlying economic mechanisms.
Presenting six articles in this thesis, I contribute towards this understanding. To this end, I expand on local impacts under current and future climate, the resulting global economic response, as well as the methods and tools to analyze this response.
Starting with a traditional assessment of weather extremes under climate change, the first article investigates extreme snowfall in the Northern Hemisphere until the end of the century. Analyzing an ensemble of global climate model projections reveals an increase of the most extreme snowfall, while mean snowfall decreases.
Assessing repercussions beyond local impacts, I employ numerical simulations to compute indirect economic effects from weather extremes with the numerical agent-based shock propagation model Acclimate. This model is used in conjunction with the recently emerged storyline framework, which involves analyzing the impacts of a particular reference extreme event and comparing them to impacts in plausible counterfactual scenarios under various climate or socio-economic conditions. Using this approach, I introduce three primary storylines that shed light on the complex mechanisms underlying economic loss propagation.
In the second and third articles of this thesis, I analyze storylines for the historical Hurricanes Sandy (2012) and Harvey (2017) in the USA. For this, I first estimate local economic output losses and then simulate the resulting global economic response with Acclimate. The storyline for Hurricane Sandy thereby focuses on global consumption price anomalies and the resulting changes in consumption. I find that the local economic disruption leads to a global wave-like economic price ripple, with upstream effects propagating in the supplier direction and downstream effects in the buyer direction. Initially, an upstream demand reduction causes consumption price decreases, followed by a downstream supply shortage and increasing prices, before the anomalies decay in a normalization phase. A dominant upstream or downstream effect leads to net consumption gains or losses of a region, respectively. Moreover, I demonstrate that a longer direct economic shock intensifies the downstream effect for many regions, leading to an overall consumption loss.
The third article of my thesis builds upon the developed loss estimation method by incorporating projections to future global warming levels. I use these projections to explore how the global production response to Hurricane Harvey would change under further increased global warming. The results show that, while the USA is able to nationally offset direct losses in the reference configuration, other countries have to compensate for increasing shares of counterfactual future losses. This compensation is mainly achieved by large exporting countries, but gradually shifts towards smaller regions. These findings not only highlight the economy’s ability to flexibly mitigate disaster losses to a certain extent, but also reveal the vulnerability and economic disadvantage of regions that are exposed to extreme weather events.
The storyline in the fourth article of my thesis investigates the interaction between global economic stress and the propagation of losses from weather extremes. I examine indirect impacts of weather extremes — tropical cyclones, heat stress, and river floods — worldwide under two different economic conditions: an unstressed economy and a globally stressed economy, as seen during the Covid-19 pandemic. I demonstrate that the adverse effects of weather extremes on global consumption are strongly amplified when the economy is under stress. Specifically, consumption losses in the USA and China double and triple, respectively, due to the global economy’s decreased capacity for disaster loss compensation. An aggravated scarcity intensifies the price response, causing consumption losses to increase.
Advancing on the methods and tools used here, the final two articles in my thesis extend the agent-based model Acclimate and formalize the storyline approach. With the model extension described in the fifth article, regional consumers make rational choices on the goods bought such that their utility is maximized under a constrained budget. In an out-of-equilibrium economy, these rational consumers are shown to temporarily increase consumption of certain goods in spite of rising prices.
The sixth article of my thesis proposes a formalization of the storyline framework, drawing on multiple studies including storylines presented in this thesis. The proposed guideline defines eight central elements that can be used to construct a storyline.
Overall, this thesis contributes towards a better understanding of economic repercussions of weather extremes. It achieves this by providing assessments of local direct impacts, highlighting mechanisms and impacts of loss propagation, and advancing on methods and tools used.
The CH2Cl2/MeOH (1:1) extract of Zanthoxylum holstzianum stem bark showed good antiplasmodial activity (IC50 2.5 +/- 0.3 and 2.6 +/- 0.3 mu g/mL against the W2 and D6 strains of Plasmodium falciparum, respectively). From the extract five benzophenanthridine alkaloids [8-acetonyldihydrochelerythrine (1), nitidine (2), dihydrochelerythine (3), norchelerythrine (5), arnottianamide (8)]; a 2-quinolone alkaloid [N-methylflindersine (4)]; a lignan [4,4 '-dihydroxy-3,3 '-dimethoxylignan-9,9 '-diyl diacetate (7)] and a dimer of a benzophenanthridine and 2-quinoline [holstzianoquinoline (6)] were isolated. The CH2Cl2/MeOH (1:1) extract of the root bark afforded 1, 3-6, 8, chelerythridimerine (9) and 9-demethyloxychelerythrine (10). Holstzianoquinoline (6) is new, and is the second dimer linked by a C-C bond of a benzophenanthridine and a 2-quinoline reported thus far. The compounds were identified based on spectroscopic evidence. Amongst five compounds (1-5) tested against two strains of P. falciparum, nitidine (IC50 0.11 +/- 0.01 mu g/mL against W2 and D6 strains) and norchelerythrine (IC50 value of 0.15 +/- 0.01 mu g/mL against D6 strain) were the most active.
Droughts in São Paulo
(2023)
Literature has suggested that droughts and societies are mutually shaped and, therefore, both require a better understanding of their coevolution on risk reduction and water adaptation. Although the Sao Paulo Metropolitan Region drew attention because of the 2013-2015 drought, this was not the first event. This paper revisits this event and the 1985-1986 drought to compare the evolution of drought risk management aspects. Documents and hydrological records are analyzed to evaluate the hazard intensity, preparedness, exposure, vulnerability, responses, and mitigation aspects of both events. Although the hazard intensity and exposure of the latter event were larger than the former one, the policy implementation delay and the dependency of service areas in a single reservoir exposed the region to higher vulnerability. In addition to the structural and non-structural tools implemented just after the events, this work raises the possibility of rainwater reuse for reducing the stress in reservoirs.
Its properties make copper one of the world’s most important functional metals. Numerous megatrends are increasing the demand for copper. This requires the prospection and exploration of new deposits, as well as the monitoring of copper quality in the various production steps. A promising technique to perform these tasks is Laser Induced Breakdown Spectroscopy (LIBS). Its unique feature, among others, is the ability to measure on site without sample collection and preparation. In this work, copper-bearing minerals from two different deposits are studied. The first set of field samples come from a volcanogenic massive sulfide (VMS) deposit, the second part from a stratiform sedimentary copper (SSC) deposit. Different approaches are used to analyze the data. First, univariate regression (UVR) is used. However, due to the strong influence of matrix effects, this is not suitable for the quantitative analysis of copper grades. Second, the multivariate method of partial least squares regression (PLSR) is used, which is more suitable for quantification. In addition, the effects of the surrounding matrices on the LIBS data are characterized by principal component analysis (PCA), alternative regression methods to PLSR are tested and the PLSR calibration is validated using field samples.
Keep on scrolling?
(2023)
Smartphones are an integral part of daily life for many people worldwide. However, concerns have been raised that long usage times and the fragmentation of daily life through smartphone usage are detrimental to well-being. This preregistered study assesses (1) whether differences in smartphone usage behaviors between individuals predict differences in a variety of well-being measures (between-person effects) and (2) whether differences in smartphone usage behaviors between situations predict whether an individual is feeling better or worse (within-person effects). In addition to total usage time, several indicators capturing the fragmentation of usage/nonusage time were developed. The study combines objectively measured smartphone usage with self-reports of well-being in surveys (N = 236) and an experience sampling period (N = 378, n = 5775 datapoints). To ensure the robustness of the results, we replicated our analyses in a second measurement period (surveys: N = 305; experience sampling: N = 534, n = 7287 datapoints) and considered the pattern of effects across different operational definitions and constructs. Results show that individuals who use their smartphone more report slightly lower well-being (between-person effect) but no evidence for within-person effects of total usage time emerged. With respect to fragmentation, we found no robust association with well-being.
This study utilizes cross-country survey data to analyze differences in attitudes toward cryptocurrency as an alternative to traditional money issued by a central bank. Particularly, we investigate women’s general attitude toward cryptocurrency systems. Results suggest that women invest less into cryptocurrency, show less interest in the future cryptocurrency investment, and see less economic potential in these systems than men do. Further evidence shows that these attitudes are directly connected with lower literacy in cryptocurrency systems. These findings support theory on gender differences in investment behavior. We contribute to the existing literature by conducting a cross-country survey on cryptocurrency attitudes in Europe and Asia, and hence show that this gender effect is robust across these cultures.
Extreme flooding displaces an average of 12 million people every year. Marginalized populations in low-income countries are in particular at high risk, but also industrialized countries are susceptible to displacement and its inherent societal impacts. The risk of being displaced results from a complex interaction of flood hazard, population exposed in the floodplains, and socio-economic vulnerability. Ongoing global warming changes the intensity, frequency, and duration of flood hazards, undermining existing protection measures. Meanwhile, settlements in attractive yet hazardous flood-prone areas have led to a higher degree of population exposure. Finally, the vulnerability to displacement is altered by demographic and social change, shifting economic power, urbanization, and technological development. These risk components have been investigated intensively in the context of loss of life and economic damage, however, only little is known about the risk of displacement under global change.
This thesis aims to improve our understanding of flood-induced displacement risk under global climate change and socio-economic change. This objective is tackled by addressing the following three research questions. First, by focusing on the choice of input data, how well can a global flood modeling chain reproduce flood hazards of historic events that lead to displacement? Second, what are the socio-economic characteristics that shape the vulnerability to displacement? Finally, to what degree has climate change potentially contributed to recent flood-induced displacement events?
To answer the first question, a global flood modeling chain is evaluated by comparing simulated flood extent with satellite-derived inundation information for eight major flood events. A focus is set on the sensitivity to different combinations of the underlying climate reanalysis datasets and global hydrological models which serve as an input for the global hydraulic model. An evaluation scheme of performance scores shows that simulated flood extent is mostly overestimated without the consideration of flood protection and only for a few events dependent on the choice of global hydrological models. Results are more sensitive to the underlying climate forcing, with two datasets differing substantially from a third one. In contrast, the incorporation of flood protection standards results in an underestimation of flood extent, pointing to potential deficiencies in the protection level estimates or the flood frequency distribution within the modeling chain.
Following the analysis of a physical flood hazard model, the socio-economic drivers of vulnerability to displacement are investigated in the next step. For this purpose, a satellite- based, global collection of flood footprints is linked with two disaster inventories to match societal impacts with the corresponding flood hazard. For each event the number of affected population, assets, and critical infrastructure, as well as socio-economic indicators are computed. The resulting datasets are made publicly available and contain 335 displacement events and 695 mortality/damage events. Based on this new data product, event-specific displacement vulnerabilities are determined and multiple (national) dependencies with the socio-economic predictors are derived. The results suggest that economic prosperity only partially shapes vulnerability to displacement; urbanization, infant mortality rate, the share of elderly, population density and critical infrastructure exhibit a stronger functional relationship, suggesting that higher levels of development are generally associated with lower vulnerability.
Besides examining the contextual drivers of vulnerability, the role of climate change in the context of human displacement is also being explored. An impact attribution approach is applied on the example of Cyclone Idai and associated extreme coastal flooding in Mozambique. A combination of coastal flood modeling and satellite imagery is used to construct factual and counterfactual flood events. This storyline-type attribution method allows investigating the isolated or combined effects of sea level rise and the intensification of cyclone wind speeds on coastal flooding. The results suggest that displacement risk has increased by 3.1 to 3.5% due to the total effects of climate change on coastal flooding, with the effects of increasing wind speed being the dominant factor.
In conclusion, this thesis highlights the potentials and challenges of modeling flood- induced displacement risk. While this work explores the sensitivity of global flood modeling to the choice of input data, new questions arise on how to effectively improve the reproduction of flood return periods and the representation of protection levels. It is also demonstrated that disentangling displacement vulnerabilities is feasible, with the results providing useful information for risk assessments, effective humanitarian aid, and disaster relief. The impact attribution study is a first step in assessing the effects of global warming on displacement risk, leading to new research challenges, e.g., coupling fluvial and coastal flood models or the attribution of other hazard types and displacement events. This thesis is one of the first to address flood-induced displacement risk from a global perspective. The findings motivate for further development of the global flood modeling chain to improve our understanding of displacement vulnerability and the effects of global warming.
The objective of the present paper is to explore the potentials and challenges inherent in con- ceptualizations of global citizenship education (GCE) in the context of foreign language edu- cation. Specifically, we argue for a critical approach to GCE that emphasizes the significance of language as symbolic power by drawing on the concepts of critical literacy (e.g., Freire 1983; Janks 2014) and symbolic competence (Kramsch 2006; 2011; 2021). To illustrate the necessity of such a critical approach to GCE, we critically analyze teaching materials designed for the English language classroom as provided by the curriculum framework (KMK/ BMZ 2016). The analysis reveals how reliance on dominant Western liberal and neoliberal epistemologies, norms, and discourses might inadvertently reinforce the very inequalities that GCE actually seeks to address. By foregrounding the relationship between language, symbolic power, and GCE, we further redesign these teaching materials and incorporate pedagogical and methodological principles which are in line with a critical literacy and symbolic competence.
When moral authority speaks
(2023)
Portal Wissen = Learning
(2023)
Changing through learning is one of the most important characteristics we humans have. We are born and can – it seems – do nothing. We have to comprehend, copy, and acquire everything: grasping and walking, eating and speaking. Of course, we also have to read and do number work. In the meantime, we know: We will never be able to finish this. At best, we learn for a lifetime. If we stop, it harms us. The Greek philosopher Plato said more than 2,400 years ago, “There is no shame in not knowing something. The shame is in not being willing to learn.”
As humans we are also capable of learning; thanks to more and more knowledge about the world around us, we have moved from the Stone Age into the digital age. That this development is not a finish line either, but that we still have a long way to go, is shown by man-made climate change – and above all by our inability as a global community to translate what research teaches us into appropriate actions. Let us dare to hope that we also comprehend this.
What we tend to ignore in the intensive discussion about the multi-layered levels of learning: We are by no means the only learners. Many, if not all, living beings on our planet learn, some more in a more purposeful and complex and more cognitive way than others. And for some time now, machines have also been able to learn more or less independently. Artificial intelligence sends its regards.
The significance of learning for human beings can hardly be overestimated. Science has also understood this and has discovered the learning processes and conditions in almost all contexts for itself, no matter whether it is about our own learning processes and conditions or those around us. We have investigated some of these for the current issue of “Portal Wissen”.
Psycholinguist Natalie Boll-Avetisyan has developed a box that can be used to detect language learning disorders already in young children. The behavioral biologists Jana Eccard and Valeria Mazza investigated the behavior of small rodents and found out that they do not only develop different personality traits but they also described how they learn to adapt them different environmental conditions. Computer linguist David Schlangen examines the question what machines have to learn so that our communication with them works even better.
Since research is ultimately always a learning process that strives to understand something yet unknown, this time all texts are somehow along the motto of the title theme: It is about what the history of past centuries reveals about “military cultures of violence” and the question of what lessons we should learn from natural hazards for the future.
We talked with a legal scholar who looks beyond the university’s backyard and wants to make law comprehensible to everyone. We also talked with a philosopher who analyzes why “having an opinion” means something different today than 100 years ago. We report about an AI-based genome analysis that can change healthcare sustainably. Furthermore, it is about the job profile “YouTuber”, minor cosmopolitanisms, and wildlife management in Africa. When you have finished reading, you will have learnt something. Promised! Enjoy your read!
The kinetics of water transfer between the lower critical solution temperature (LCST) and upper critical solution temperature (UCST) thermoresponsive blocks in about 10 nm thin films of a diblock copolymer is monitored by in situ neutron reflectivity. The UCST-exhibiting block in the copolymer consists of the zwitterionic poly(4((3-methacrylamidopropyl)dimethylammonio)butane-1-sulfonate), abbreviated as PSBP. The LCST-exhibiting block consists of the nonionic poly(N-isopropylacrylamide), abbreviated as PNIPAM. The as-prepared PSBP80-b-PNIPAM(400) films feature a three-layer structure, i.e., PNIPAM, mixed PNIPAM and PSBP, and PSBP. Both blocks have similar transition temperatures (TTs), namely around 32 degrees C for PNIPAM, and around 35 degrees C for PSBP, and with a two-step heating protocol (20 degrees C to 40 degrees C and 40 degrees C to 80 degrees C), both TTs are passed. The response to such a thermal stimulus turns out to be complex. Besides a three-step process (shrinkage, rearrangement, and reswelling), a continuous transfer of D2O from the PNIPAM to the PSBP block is observed. Due to the existence of both, LCST and UCST blocks in the PSBP80-b-PNIPAM(400 )film, the water transfer from the contracting PNIPAM, and mixed layers to the expanding PSBP layer occurs. Thus, the hydration kinetics and thermal response differ markedly from a thermoresponsive polymer film with a single LCST transition.
The long term relationship between medicaid expansion and adult life-threatening chronic conditions
(2023)
We test whether the expansions of children's Medicaid eligibility in the 1980s–1990s resulted in long-term health benefits in terms of severe chronic conditions. Still relatively rare in the field, we use prospective individual-level panel data from the Panel Study of Income Dynamics (PSID) along with the higher quality income measures from the Cross-National Equivalent File (adjusting for taxes, transfers and household size). We observe severe chronic conditions (high blood pressure/heart disease, cancer, diabetes, or lung disease) at ages 30–56 (average age 43.1) for 4670 respondents who were also prospectively observed during childhood (i.e., at ages 0–17). Our analysis exploits within-region temporal variation in childhood Medicaid eligibility and adjusts for state- and individual-level controls. We uniquely concentrate attention on adjusting for childhood income. A standard deviation greater childhood Medicaid eligibility significantly reduces the probability of severe chronic conditions in adulthood by 0.05 to 0.12 (16%–37.5% reduction from mean 0.32). Across the range of observed childhood Medicaid eligibility, the probability is approximately cut in half. Greater childhood Medicaid eligibility also substantially reduces childhood income disparities in severe chronic conditions. At higher levels of childhood Medicaid eligibility, we find no significant childhood income disparities in adult severe chronic conditions.
Introduction
(2023)
Can a metamorphosis of international law be identified while it is still underway? In Chapter 1, the Introduction, Krieger and Liese set the stage for the interdisciplinary assessment of the effects of the current crisis of the international legal order. They offer fundamental common values as a reference point and yardstick to systematically evaluate and analyse normative changes in international law. After explaining the benefits of interdisciplinary exchange and clarifying the basic concepts from the respective disciplinary perspectives, they develop the book’s conceptual framework for assessing and explaining value change in the international legal order. The Introduction also elaborates on the book’s research design and case selection and summarizes the aims and key contributions of each conceptual and empirical chapter.
New Relations in the Making?
(2023)
Against the pain
(2023)
Although prior research has shown that reward provision might sometimes increase creativity, little is known about how leadership that clarifies effort-reward contingencies (i.e., contingent reward leadership) is related to team creativity. Drawing on the theory of learned industriousness, we argue that contingent reward leadership can enhance team knowledge exchange and, in turn, team creative performance. However, we propose that this relationship is moderated by leader unpredictability, which can create uncertainty about resource allocation, thereby undermining the otherwise positive effect of contingent reward leadership. In a two-source, lagged design (three-wave) field study with data from 60 organizational teams, we found a conditional indirect (moderated mediation) effect of contingent reward leadership on team creative performance through team knowledge exchange. This conditional indirect effect was positive when leader unpredictability was low, and negative when leader unpredictability was high. Our research provides leaders with clear and actionable advice by showing that contingent reward leadership promotes team creative performance only when leaders act in predictable and consistent ways.
Enterprise Resource Planning (ERP) systems are critical to the success of enterprises, facilitating business operations through standardized digital processes. However, existing ERP systems are unsuitable for startups and small and medium-sized enterprises that grow quickly and require adaptable solutions with low barriers to entry. Drawing upon 15 explorative interviews with industry experts, we examine the challenges of current ERP systems using the task technology fit theory across companies of varying sizes. We describe high entry barriers, high costs of implementing implicit processes, and insufficient interoperability of already employed tools. We present a vision of a future business process platform based on three enablers: Business processes as first-class entities, semantic data and processes, and cloud-native elasticity and high availability. We discuss how these enablers address current ERP systems' challenges and how they may be used for research on the next generation of business software for tomorrow's enterprises.
Scholars have argued that visionary leadership is an effective tool to motivate followers because it provides them with meaning and purpose. However, previous research tells us little about which leaders and under which circumstances leaders engage in visionary leadership. We draw on theories of human and social capital to argue that leader work centrality is an important antecedent of visionary leadership, and especially so for leaders with low organizational tenure. Moreover, we propose that visionary leadership then provides followers with meaningfulness and thereby decreases their turnover intentions. Our predictions were confirmed by data from a two-wave, lagged-design field study with 101 leader-follower dyads. Overall, our research identifies an important antecedent of visionary leadership, a specific situation in which this antecedent is particularly important, and provides empirical evidence for why visionary leadership can bind followers to an organization.