Showing papers by "University of Konstanz published in 2023"

Schwartz Function Valued Solutions of the Euler and the Navier-Stokes Equations

Abstract: Abstract We prove the existence of a solution for the second order system of partial differential equations ∂ t f = Δ f + g . ∇ f + h . f + k by a Montel space version of Arzelà--Ascoli and bound all Schwartz semi-norms. We find that for the Euler and the Navier--Stokes equations the vorticity remains a Schwartz function as long as the classical solution exists. Our approach is not affected by viscosity. It treats the hyperbolic Euler and the parabolic Navier--Stokes equation simultaneously. 2020 MSC: 35Q30, 76D03, 76D05

Who cares for the future? Exploring public attitudes towards the needs of future generations in Germany

Abstract: This paper studies the determinants of support for future generations, using novel survey data for the case of Germany. I find significant, but not overwhelming support for prioritizing the needs of future generations vs. the acute needs of present-day citizens. Moreover, individual-level and contextual factors matter too. High-income and highly educated citizens are on average more supportive of the needs of future generations, the elderly and women less so. Left-wing supporters are equally more supportive of future generations, especially supporters of the Greens and those subscribing to ‘green-alternative-liberal’ values. Supporters of the right-wing populist AfD are most strongly opposed. General political trust boosts support for future generations, and economically thriving local economies are associated with higher levels of support for future generations as well.

Spin Glass Systems as Collective Active Inference

Abstract: An open question in the study of emergent behaviour in multi-agent Bayesian systems is the relationship, if any, between individual and collective inference. In this paper we explore the correspondence between generative models that exist at two distinct scales, using spin glass models as a sandbox system to investigate this question. We show that the collective dynamics of a specific type of active inference agent is equivalent to sampling from the stationary distribution of a spin glass system. A collective of specifically-designed active inference agents can thus be described as implementing a form of sampling-based inference (namely, from a Boltzmann machine) at the higher level. However, this equivalence is very fragile, breaking upon simple modifications to the generative models of the individual agents or the nature of their interactions. We discuss the implications of this correspondence and its fragility for the study of multiscale systems composed of Bayesian agents.

Comment on egusphere-2023-422

Abstract: Abstract. Reservoirs can emit substantial amounts of the greenhouse gas methane (CH₄) via different emission pathways. In some reservoirs, reservoir flushing is employed as a sediment management strategy to counteract growing sediment deposits that threaten reservoir capacity. Reservoir flushing utilizes the eroding force of water currents during water level drawdown to mobilize and transport sediment deposits through the dam outlet into the downstream river. During this process, CH₄ that is stored in the sediment can be released into the water and degas to the atmosphere resulting in CH₄ emissions. Here, we assess the significance of this CH₄ emission pathway and compare it to other CH₄ emission pathways from reservoirs. We measured seasonal and spatial CH₄ concentrations in the sediment of Schwarzenbach Reservoir, providing one of the largest datasets on CH₄ pore water concentrations in freshwater systems. Based on this dataset we determined CH₄ fluxes from the sediment and estimated potential CH₄ emissions due to reservoir flushing. CH₄ emissions due to one flushing operation can constitute 7–14 % of the typical annual CH₄ emissions from Schwarzenbach Reservoir, whereby the amount of released CH₄ depends on the timing of the flushing operation within the season. The larger the thickness of the sediment layer mobilized during the flushing operation the larger the average CH₄ concentration per unit volume of flushed sediment. This suggests that regular flushing of smaller sediment layers releases less CH₄ than removal of the same sediment volume in fewer flushing events of thicker sediment layers. In other reservoirs with higher sediment loadings than Schwarzenbach Reservoir, reservoir flushing could cause substantial CH₄ emissions, especially when flushing operations are conducted frequently. Therefore, CH₄ emissions due to reservoir flushing must be included in estimates of annual overall greenhouse gas emissions from reservoirs that are subject to regular flushing operations.

Reply on RC1

Abstract: Abstract. Reservoirs can emit substantial amounts of the greenhouse gas methane (CH₄) via different emission pathways. In some reservoirs, reservoir flushing is employed as a sediment management strategy to counteract growing sediment deposits that threaten reservoir capacity. Reservoir flushing utilizes the eroding force of water currents during water level drawdown to mobilize and transport sediment deposits through the dam outlet into the downstream river. During this process, CH₄ that is stored in the sediment can be released into the water and degas to the atmosphere resulting in CH₄ emissions. Here, we assess the significance of this CH₄ emission pathway and compare it to other CH₄ emission pathways from reservoirs. We measured seasonal and spatial CH₄ concentrations in the sediment of Schwarzenbach Reservoir, providing one of the largest datasets on CH₄ pore water concentrations in freshwater systems. Based on this dataset we determined CH₄ fluxes from the sediment and estimated potential CH₄ emissions due to reservoir flushing. CH₄ emissions due to one flushing operation can constitute 7–14 % of the typical annual CH₄ emissions from Schwarzenbach Reservoir, whereby the amount of released CH₄ depends on the timing of the flushing operation within the season. The larger the thickness of the sediment layer mobilized during the flushing operation the larger the average CH₄ concentration per unit volume of flushed sediment. This suggests that regular flushing of smaller sediment layers releases less CH₄ than removal of the same sediment volume in fewer flushing events of thicker sediment layers. In other reservoirs with higher sediment loadings than Schwarzenbach Reservoir, reservoir flushing could cause substantial CH₄ emissions, especially when flushing operations are conducted frequently. Therefore, CH₄ emissions due to reservoir flushing must be included in estimates of annual overall greenhouse gas emissions from reservoirs that are subject to regular flushing operations.

Do women evaluate their lower earnings still to be fair? Findings on the contented female worker paradox examining the role of occupational contexts in 27 European countries

Abstract: Abstract It is still a puzzling question which gender inequalities in the labour market are perceived as fair and which are not – in the eye of the beholder. This study focuses on gender differences in the perceptions of the fairness of one’s own wage and the role of the occupational context individuals are embedded in. Based on data collected from 27 European countries as part of the 2018 European Social Survey (Round 9), our study contributes to the growing field of wage fairness perceptions by analysing the role of the occupational context (measured as the share of women and the gender pay gap in the respondent’s occupation), and how it moderates gender differences in fairness perceptions. Results indicate that – overall – female workers across Europe perceive their wages more often as unfairly “too low” than their male counterparts within the same country context and occupation, and that this gender gap is more pronounced in occupations with a high proportion of women and higher levels of gender inequality. We interpret these results as an indicator of growing awareness among women regarding the persisting “unfair” gendered wage distributions.

High Homogeneity of Mesothelin Expression in Primary and Metastatic Ovarian Cancer

Abstract: To study the extent of heterogeneity of mesothelin overexpression in primary ovarian cancers and their peritoneal and lymph node metastases, a tissue microarray (TMA) was constructed from multiple sites of 220 ovarian cancers and analyzed by immunohistochemistry. One tissue core each was taken from up to 18 different tumor blocks per cancer, resulting in a total of 2460 tissue spots from 423 tumor sites (188 primary cancers, 162 peritoneal carcinosis, and 73 lymph node metastases). Positive mesothelin expression was found in 2041 of the 2342 (87%) arrayed tissue spots and in 372 of the 392 (95%) tumor sites that were interpretable for mesothelin immunohistochemistry. Intratumoral heterogeneity was found in 23% of 168 primary cancer sites interpretable for mesothelin and decreased to 12% in 154 peritoneal carcinosis and to 6% in 71 lymph node metastases (P<0.0001). Heterogeneity between the primary tumor and matched peritoneal carcinosis was found in 16% of 102 cancers with interpretable mesothelin results. In these cancers, the mesothelin status switched from positive in the primary tumor to negative in the peritoneal carcinosis (3 cancers) in or vice versa (2 cancers), or a mixture of positive and negative peritoneal carcinoses was found (11 cancers). No such switch was seen between the mesothelin-interpretable primary tumors and their nodal metastases of 59 cancers, and only 1 mesothelin-positive tumor had a mixture of positive and negative lymph node metastases. In conclusion, mesothelin expression is frequent and highly homogeneous in ovarian cancer.

Catalytic Biorefining of Natural Oils to Basic Olefinic Building Blocks of Proven Chemical Valorization Schemes

Abstract: Catalytic transformation of renewable plant oils including microalgae and waste oil into industrially relevant α-olefins in the C3 to C10 regime is demonstrated. The biorefinery concept is comprised of a catalytic sequence of ethenolysis, double bond isomerization, and a subsequent ethenolysis, thereby cutting and rearranging the fatty acid chains into valuable chemical building blocks. A benign extraction and reaction solvent, supercritical carbon dioxide (scCO2), is utilized.

Relevance of organic vs. inorganic nitrogen in intra- and interspecific competition of seven central European tree species

Abstract: Abstract Key message When competing for nitrogen with other tree species, organic N is more important than inorganic N for most species Abstract Competition for nitrogen (N) in the rhizosphere is a key process regulating a seedling´s chances for growth and survival. However, only few studies have investigated this at the individual species´ level when using a community approach. In this study, 15 N incubation experiments were conducted to quantify inorganic (i.e. ammonium and nitrate) and organic (i.e. glutamine-N and arginine-N) net N-uptake capacity of seven temperate woody species co-occurring on calcareous substrate and to investigate the consequences of intra- vs. interspecific competition in a woody seedling community. The results showed that short-term net inorganic and organic N uptake capacity was unrelated to a seedling´s fast or slow growth. Furthermore, competition with other tree species did not change a seedlings´ overall capacity to take up inorganic and organic N sources. Organic N was preferred over inorganic N for most species and the preferences for specific N source shifted with competition regime and tree species. Overall, this study indicates the importance of organic N sources for N uptake in woody seedlings.

Introduction

Abstract: Abstract This thesis addresses the issue of translating mathematical expressions from LATEX to the syntax of Computer Algebra Systems (CAS), which is typically a time-consuming and error-prone task in the modern life of many researchers. A reliable and comprehensive translation approach requires analyzing the textual context of mathematical formulae. In turn, research advances in translating LATEX contribute directly towards related tasks in the Mathematical Information Retrieval (MathIR) arena.

Patterns of parent screen use, child screen time, and child socio‐emotional problems at 5 years

Abstract: Digital media screens have become an essential part of our family life. However, we have insufficient knowledge about parental screen use patterns and how these affect children's socio-emotional development. In total, 867 Canadian parents of 5-year-old children from the TARGet Kids! Cohort (73.1% mothers, mean ± SD age = 38.88 ± 4.45 years) participated in this study from 2014 to the end of 2019. Parents reported parental and child time on television (TV) and handheld devices and completed the Strengths and Difficulties Questionnaire (SDQ). Latent profile analysis identified six latent profiles of parent screen use: low handheld users (P1, reference; n = 323), more TV than handheld (P2; n = 261), equal TV and handheld (P3; n = 177), more handheld than TV (P4; n = 57), high TV and handheld (P5; n = 38), and extremely high TV and handheld (P6; n = 11). Parents that were more likely to belong to P6 were also more likely to be living in single-parent households compared to P1 (estimate = −1.49 ± 0.70), p = .03). High membership probability for P2 (estimate = −0.67 ± 0.32, p = .04) and P4 (estimate = −1.42 ± 0.40, p < 0.001) was associated with lower household income compared to P1. Children of parents with higher P4 (χ2 = 12.32, p < 0.001) or P5 (χ2 = 9.54, p = .002) membership probability had higher total screen time compared to P1. Finally, a higher likelihood to belong to P6 (χ2 = 6.82, p = .009) was associated with a higher SDQ Total Difficulties Score compared to P1. Thus, patterns of parent screen use were associated with child screen use and child socio-emotional problems. The emerging link between parental screen use profiles and child behaviors suggests the need for more research on parent screen time.

Mass Euroscepticism revisited: The role of distributive justice

Abstract: This article advances research into mass Euroscepticism by investigating the role of distributive justice. Drawing on cross-national survey data from 23 countries, the study shows that perceived injustice of individual opportunities (i.e. educational and job opportunities) and outcomes (i.e. earnings) nourish Eurosceptic sentiments, independent of objective inequalities. However, the public response to distributive injustice varies across European Union (EU) member states, as high domestic corruption levels dampen the apparent link to EU accountability. Perceptions of injustice concerning earnings provide a potential breeding ground for Euroscepticism in member states with low levels of corruption, while EU scapegoating regarding earnings injustice does not manifest itself in member states with the highest levels of corruption. These results are supportive of a justice-based approach in understanding varieties of Euroscepticism across Europe.

Transversal Similarities: Philology Beyond Tradition, Influence and Interconnectedness

Abstract: The contribution is based on the experiences of a German scholar with the research interests of students of non-European origin, specifically from China. In the two exemplary works discussed, German-Chinese comparisons are made that go beyond national-philologically anchored notions of comparability. In one case, it is a matter of observed similarities between the idylls of Salomon Gessner from the eighteenth century on the one hand, and poems by Tao Yuanming from the fourth century B.C.E. on the other. In the other paper, a dissertation, the contemporary Chinese writer Mo Yan is compared with Jean Paul (1763–1825) on the basis of his humorous encyclopedic writing procedures. The works compared in each case are not linked by a common epochal context, nor by recourse to common traditions, nor by relations of influence or entanglement. Nevertheless, similarities cannot be dismissed out of hand. This raises the question of how such transversal similarities can be conceptualized and explained beyond the paradigm of cultural difference.

Qualitative and Quantitative Evaluations

Abstract: Abstract This chapter primarily contributes to the research task V , i.e., evaluating the effectiveness of the semantification and translation system LACAST . In Section 5.1, we also extend LACAST semantic LATEX translations to support more mathematical operators, including sums, products, integrals, and limit notations. Hence, this chapter secondarily also contributes to research task IV , i.e., implementing an extension of the semantification approach to provide translations to CAS. We evaluate LACAST on two different datasets: the DLMF and Wikipedia.

Population dynamics hide phenotypic changes driven by subtle chemical exposures: implications for risk assessments

Abstract: Ecological risk assessment of chemicals focuses on the response of different taxa in isolation not taking ecological and evolutionary interplay in communities into account. Its consideration would, however, allow for an improved assessment by testing for implications within and across trophic levels and changes in the phenotypic and genotypic diversity within populations. We present a simple experimental system that can be used to evaluate the ecological and evolutionary responses to chemical exposure at microbial community levels. We exposed a microbial model system of the ciliate Tetrahymena thermophila (predator) and the bacterium Pseudomonas fluorescens (prey) to iron released from Magnetic Particles (MP-Fedis), which are Phosphorus (P) adsorbents used in lake restoration. Our results show that while the responses of predator single population size differed across concentrations of MP-Fedis and the responses of prey from communities differed also across concentration of MP-Fedis, the community responses (species ratio) were similar for the different MP-Fedis concentrations. Looking further at an evolutionary change in the bacterial prey defence, we found that MP-Fedis drove different patterns and dynamics of defence evolution. Overall, our study shows how similar community dynamics mask changes at evolutionary levels what would be overlooked in the design of current risk assessment protocols where evolutionary approaches are not considered.

Reply on RC2

Abstract: Abstract. Reservoirs can emit substantial amounts of the greenhouse gas methane (CH₄) via different emission pathways. In some reservoirs, reservoir flushing is employed as a sediment management strategy to counteract growing sediment deposits that threaten reservoir capacity. Reservoir flushing utilizes the eroding force of water currents during water level drawdown to mobilize and transport sediment deposits through the dam outlet into the downstream river. During this process, CH₄ that is stored in the sediment can be released into the water and degas to the atmosphere resulting in CH₄ emissions. Here, we assess the significance of this CH₄ emission pathway and compare it to other CH₄ emission pathways from reservoirs. We measured seasonal and spatial CH₄ concentrations in the sediment of Schwarzenbach Reservoir, providing one of the largest datasets on CH₄ pore water concentrations in freshwater systems. Based on this dataset we determined CH₄ fluxes from the sediment and estimated potential CH₄ emissions due to reservoir flushing. CH₄ emissions due to one flushing operation can constitute 7–14 % of the typical annual CH₄ emissions from Schwarzenbach Reservoir, whereby the amount of released CH₄ depends on the timing of the flushing operation within the season. The larger the thickness of the sediment layer mobilized during the flushing operation the larger the average CH₄ concentration per unit volume of flushed sediment. This suggests that regular flushing of smaller sediment layers releases less CH₄ than removal of the same sediment volume in fewer flushing events of thicker sediment layers. In other reservoirs with higher sediment loadings than Schwarzenbach Reservoir, reservoir flushing could cause substantial CH₄ emissions, especially when flushing operations are conducted frequently. Therefore, CH₄ emissions due to reservoir flushing must be included in estimates of annual overall greenhouse gas emissions from reservoirs that are subject to regular flushing operations.