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Towards a spatial measure of SDG 11.1.1:Open data for urban deprivation mapping
No full textUrban deprivation mapping is critical for addressing inequalities and achieving Sustainable Development Goal (SDG) 11.1.1, which focuses on ensuring access to adequate housing and services in urban areas. This study introduces a geospatial framework to operationalize previously conceptualized urban Domains of Deprivation related to unplanned urbanization, limited infrastructure, and limited services within city segments at the city-scale. Leveraging open, global datasets, including Google’s V3 building footprints and 2.5D building heights, the model assigns deprivation scores (ranging from 0 to 6) based on binary thresholds derived from median values. Validation against reference slum boundaries provided by the IDEAMAPS network achieved an F1- score of 0.45 for high-deprivation areas. The results highlight the spatial distribution of deprivation across Nairobi and demonstrate the reliability of dense building indicators for identifying informal settlements. The framework demonstrates computational efficiency, enabling citywide analysis using accessible resources, and highlights its potential to inform urban planning and targeted interventions through scalable geospatial methodologies aligned with SDG 11.1.1
A 1100-years paleovegetation and paleoclimate record from western Türkiye linked to the North Atlantic Oscillation variability
No full textThe North Atlantic Oscillation (NAO) plays a significant role on atmospheric circulation variability in the North Atlantic region, modulating the strength and the direction of the westerly winds belt and storm tracks, affecting the precipitation patterns in the Eastern Mediterranean Region. Studies indicate significant variations in the mode of the NAO over the last millennium, largely driven by changes in solar forcing. Here, we present a palynological record from Lake Marmara, western Türkiye and a quantitative reconstruction of paleoclimate variables based on the variations of pollen taxa over the last 1100 years. The palynological records and paleoclimate reconstruction from Lake Marmara indicate that the Medieval Warm Period (MWP) was marked by low arboreal pollen (AP), high seasonality, and drier conditions, whereas the Little Ice Age (LIA) between ∼ 300–100 cal. yr BP was characterized by high AP, low seasonality, and wetter conditions. The results demonstrate a stronger alignment with the NAO variability over the past millennium compared to the other proxy records in Türkiye
Particle dynamics and dune formation in Rayleigh-Bénard convection:a particle-resolved simulation study
No full textThis paper presents numerical results for Rayleigh-Bénard convection with suspended particles at Rayleigh numbers (Formula presented) and (Formula presented), and unit Prandtl number. Accounting for their finite size makes it possible to investigate in detail the mechanism by which the particles, which are 10 % heavier than the fluid, get resuspended after settling, thus maintaining a two-phase circulating flow. It is shown that an essential component of this mechanism is the formation of particle accumulations, or ‘dunes’, on the bottom of the Rayleigh-Bénard cell. Ascending plumes become localised on these dunes. Particles are dragged up the dune slopes, and when they reach the top, are entrained into the rising plumes. Direct resuspension of particles from the cell bottom, if it happens at all, is very rare. For (Formula presented), aspect ratios (width/height) (Formula presented) are considered. It is found that in these and in the other cases simulated, at steady state, a single dune evolves, the largest linear dimension of which is comparable to the cell size. A remarkable consequence is that even at the low volume fraction considered here, 3.27 %, the particles are able to structure the flow and to determine the size and position of the largest ascending plumes. Their effect on the Nusselt number, however, remains small. This and other results are explained on the basis of the ratio of the cell-bottom viscous boundary-layer thickness to the particle diameter.</p
Science-media relationships in times of crisis and transformation
No full textContemporary grand challenges, including climate change, pandemics, and technological disruptions, require coordinated responses from science and society. Science journalism plays a critical role in meeting the societal need for scientific information, yet relationships between researchers and journalists are undergoing profound changes. Therefore, this dissertation examines what challenges arise from contemporary changes in science-media relationships and what the implications are for the roles and responsibilities of researchers and journalists. Changing media landscapes result in declining funding and increasing competition and time pressure for science journalists. Simultaneously, due to medialisation of science, researchers and research institutes are increasingly communicating directly and strategically with non-expert audiences through press releases and (social) media. Together, these trends make journalists more dependent on the information that research organisations provide, raising concerns about the independence and critical nature of science journalism.These issues became especially visible during the COVID-19 pandemic, when there was an urgent need for accurate information, and scientists and journalists had to work closely together under pressure. Scientists struggled to balance their responsibilities to inform and advise, while journalists had to stay critical and avoid becoming too close to their sources. At the same time, both parties relied heavily on model-based visualisations, such as flatten-the-curve graphs, to predict and illustrate the course of the pandemic. These visualisations require special attention, because they are difficult to explain and interpret correctly. Similar dynamics emerge in coverage of generative artificial intelligence (AI), which acts both as a subject of reporting and as a disruptive force that transforms journalistic practices. AI can help journalists with routine tasks but also raises concerns about rigour, accuracy and transparency in science journalism. Overall, the findings show that closer cooperation between scientists and journalists can increase mutual understanding, while it can also reduce independent and critical journalistic reporting. Amid rising misinformation and growing use of pre-prints and AI, assessing the quality of scientific information becomes increasingly complex. Thus, this dissertation reconsiders the roles and responsibilities of both researchers and journalists to provide insight into how they can contribute to trustworthy science journalism in times of crisis and transformation
Secondary natural vegetation gains in the Atlantic Forest do not offset losses of carbon stocks and conservation of priority areas
No full textSince secondary natural vegetation cover (NVC) constitutes an important factor for the provision of ecosystem services (e.g., helping to tackle both the climate and biodiversity crises), understanding its dynamics is essential for effective forest restoration. Yet, this has seldom been evaluated in prior studies. We examined 37 years (1985–2021) of primary NVC loss, secondary NVC dynamics (persistent and ephemeral regeneration), and their impacts on carbon stocks and on the conservation of priority areas in Brazil's Atlantic Forest biome, a global biodiversity hotspot. We developed a new framework analyzing spatial landscape configurations over time, and found that Atlantic Forest NVC decreased by 4.2 Mha driven by a gross loss of 12.8 Mha of primary NVC (~1.4 Gt of carbon lost). Secondary NVC gained 8.6 Mha (~0.170 Gt of carbon, with potential for ~0.987 Gt in 80 years) but ephemeral regeneration (i.e., loss of secondary NVC) resulted in a loss of 3.8 Mha. Deforestation caused a net loss of 1.2 Mha in priority conservation areas. Results of this study demonstrate that understanding the dynamics of ephemeral regeneration is important for evaluating restoration efforts and ecosystem services in the Atlantic Forest. Our study also demonstrates that secondary forest regeneration plays an important role in reconnecting landscapes, although its instability threatens biodiversity and ecosystem services as it fails to offset the loss of primary vegetation. Thus, halting deforestation remains the single most urgent and vital action to prevent irreversible biodiversity loss and reduce carbon emissions.</p
Why are Lead Iodide‐Based Perovskite Precursor Inks Yellow?
No full textA challenge faced by metal halide perovskite (MHP) photovoltaics is scaling up solution deposition processes to realize rapid and inexpensive manufacturing. The challenge lies in completely understanding and controlling solution speciation, nucleation, and self-assembly of iodoplumbate complexes during solvent evaporation as the liquid transforms into gels and solids. An accurate description of solution species, at all points in the transformation, is a prerequisite to design robust and reliable processes. Here, the common assumption that initial monoplumbate solution species typically invoked (e.g., [PbI6]4−) are certainly not the origin of optical absorbance at >400 nm wavelengths is disproved, as are many large particles of common “intermediate” iodoplumbate phases with face- or edge-sharing connectivity. Instead, a new perspective is offered, involving (partially) corner-sharing iodo(poly)plumbates (>1 Pb2+ per complex) that experience highly dynamic chemical environments. It is outlined how the MHP field would benefit by elucidating these phenomena. Future work is required to determine the size and kinetic behavior of polyplumbate species, and contextualize these findings in relation to broader trends in materials chemistry beyond MHPs. Ultimately, a complete explanation for the solution speciation, optical absorbance signatures, and the color of MHP precursor inks remains an open challenge to the community
Embracing Load Imbalance for Energy Optimizations:A Case-Study
No full textScientific computing is a significant consumer of supercomputing resources, and, as a consequence, performance optimization has been a long-term goal of the high-performance computing (HPC) community. However, as the complexity and computational demands of modern scientific applications grow, optimizing energy efficiency becomes critical to balance computational throughput with power constraints.To address this challenge, we propose and evaluate a methodology to improve the energy efficiency of large-scale simulations running on multi-node computing systems. Our approach is based on a key observation: when load-imbalance during a large-scale simulation is difficult to avoid or fix, it can at least be exploited to reduce the energy consumption of the simulation. This can be achieved by reducing the CPU frequency of light-loaded nodes to reduce their energy consumption, while incurring minimal overhead and no overall increase in execution time.We demonstrate this approach in practice through a case-study based on HemoCell, a large-scale scientific framework for cell-resolved blood flow simulation. We show that reducing the node frequency to match the workload proportion per node does reduce the overall energy consumption of the simulation, while only causing a negligible increase in its execution time. For our case-study we observe energy reductions of up to 23% and minimal performance loss compared to the same workloads without frequency scaling.</p
A closer look at the role of caregivers in Co-designing everyday technology for autistic young adults:A scoping review
No full textAssistive technologies designed through co-design hold promise for enhancing independence and quality of life for autistic people. By actively involving stakeholders in the development process, co-design improves the relevance of assistive technologies and empowers stakeholders by providing them with a greater sense of control. Although stakeholders are increasingly involved in co-design, the involvement of caregivers in the co-design of everyday technology, representing their own needs rather than solely representing autistic end-users, is limited, despite caregivers frequently interacting with these technologies. It is essential to incorporate their preferences and wishes into the design process. The purpose of this scoping review is to explore the role of caregivers in co-designing everyday technologies with autistic young adults, as reflected in the current literature. This research provides insights into the extent and way caregivers contribute to the co-design of everyday technologies. We systematically queried seven databases, which returned 863 records after removing duplicates. Guided by the PRISMA-ScR approach, we selected 28 studies. The findings indicate that caregivers are minimally involved in the co-design of everyday technologies. If they are involved at all, it is mainly as proxies for autistic people. Future research should involve caregivers as key stakeholders when co-designing everyday technology
Tracing Vendors:A Middlebox-Centric Study of Network Interference
No full textMiddleboxes are intermediary network devices that facilitate traffic monitoring, filtering, and modification. They serve a broad spectrum of functions, ranging from benign tasks to highly controversial ones such as censorship. A solid body of work exists that describes methods to probe or identify middleboxes from remote including censorship middleboxes; similarly, much research has gone into fingerprinting network devices. However, there is comparatively little work that aims to understand which type of devices occurs in which networks. In this study, we choose to investigate middleboxes that reside in networks reported for network interference. We use yarrpbox, a scanning tool, to detect middleboxes and map them to vendors utilizing third-party datasets. Covering more than 500 Autonomous Systems reported for interference, we identify about 250 middleboxes, which we study in detail. We find that the location of middleboxes across countries does not correlate to the Internet Freedom Index, and we identify a distribution of vendors as well as a distribution across countries that differs markedly from previous reports. Most middleboxes in the reported networks are actually likely to serve multiple purposes, and this complexity calls for new measurement methodologies to determine whether the reported interference is a byproduct of some configuration or the primary purpose of a middlebox. We also identify a number of security issues in a number of devices, lending further support for the hypothesis that middleboxes can increase the attack surface of a network. We conclude with a discussion of directions to understand middlebox deployment with further measurements.</p
Prediction of diffuser noise footprint of a ducted wind turbine
No full textThe aerodynamic broadband noise generated by ducted configurations, such as ducted wind turbines or propellers, is of research interest due to its implications for noise pollution. Accurate prediction methods for such configurations remain unavailable for low-fidelity approaches. This paper applies the thin annulus and segmentation models, an Amiet's theory based analytical framework for predicting broadband noise from hollow cylinders, to two ducted configurations. The segmentation approach is further extended to account for the angle of attack in duct geometries. First, the thin annulus model is validated using an isolated duct, showing good agreement between predictions and experimental data. Then, the models are applied to predict the broadband trailing-edge noise of a diffuser-augmented wind turbine. The results highlight the dominance of the diffuser trailing-edge noise in this configuration and demonstrate the improved prediction accuracy of the segmentation model due to its ability to account for the angle of attack. This study provides a comprehensive framework for broadband noise prediction of ducted turbine applications, using inputs derived from RANS simulations, and demonstrates how low-fidelity approaches can be effectively utilized to address the noise prediction of a ducted turbine.</p