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Spatial analysis and risk mapping of Crimean-Congo hemorrhagic fever (CCHF) in Sub-saharan Africa
Get PDFCrimean Congo hemorrhagic fever (CCHF) is a re-emerging tick-borne zoonosis that is caused by CCHF virus (CCHFV). The geographical distribution of the disease and factors that influence its occurrence are poorly known. We analysed historical records on its outbreaks in various countries across the sub-Saharan Africa (SSA) to identify hotspots and determine socioecological and demographicfactors associated with these outbreaks. We used data from historical outbreaks that were reported between 1981 and 2022 in various countries in SSA. To develop a common framework for merging the outbreak data and potential explanatory variables, we generated a common shapefile that combined Level 2 administrative units in all the countries. Several climatic, environmental, socioecological data were obtained from on-line GIS databases and extracted using the shapefile. The data were analysed using an approximate Bayesian hierarchical model using the R-INLA package. The outcome was a Boolean variable which indicated whether an administrative unit in the shapefile was affected in a given year or not. A neighborhood structure was also generated and used to account for spatial autocorrelation in the analysis. The final model that was obtained from the analysis was used to build a CCHF risk map. A total of 54 CCHF outbreaks were compiled across 414 districts in nine SSA countries. Factors that were positively associated with CCHF outbreaks included human population density, land area under grassland, bare soil cover and shrub cover. Conversely, high precipitation during wet months, elevated mean temperature and slope had negative effects. The risk map generated shows that CCHF occurrence risk is higher in arid and semi-arid land (ASAL) of West Africa, the Sahelian region, Central Africa, and the Eastern and Southern Africa region. The analysis identified ecological and demographic factors that are associated with CCHF outbreaks in SSA. This finding suggests the need to improve surveillance for the disease especially in the grasslands where the human population is increasing
Ueber den Bau der Cotyledonen im Uterus von Bos in verschiedenen Schwangerschaftsperioden
No full textDigitalisat der Ausgabe von 1903, erschienen 202
Changing affective alignments between parties and voters
Get PDFPopulist parties are held to be the drivers of unprecedented emotionalisation in electoral politics. Advancing theories of realignment and detachment, this article studies the temporal development in the affective alignments between voters and parties. In particular, it analyses the relationship between social structure, voters’ affective orientations towards political parties, and vote choice over time by drawing on 625 representative population surveys from Germany over 44 years. The results show that voters’ affective orientations are indeed becoming more important to vote choice. However, this reflects a return to the close link that already existed at the heyday of the original cleavages rather than something novel. What seems to have changed is the degree to which affective orientations are rooted in social structure. This not only qualifies overly myopic interpretations of populist success but has more general implications for the contemporary linkages between parties and voters
Epistemic authority in the digital public sphere. An integrative conceptual framework and research agenda
Get PDFWe develop an integrative conceptual framework and research agenda for studying epistemic authorities in the digital age. Consulting epistemic authorities (e.g., professional experts, well-informed laypeople, technologies) can be an efficient fast-track to knowledge. To fulfill this functional role, those who claim epistemic authority need to be both subjectively recognized (have a perceived advantage in knowledge) and objectively justified (have an actual advantage in knowledge). In a digital media context, new and unconventional knowledge sources have emerged that can fulfill the functional role of epistemic authorities. But false authorities that disseminate misinformation have emerged as well while other sources with important knowledge remain unrecognized. We further analyze the functional role of epistemic intermediaries that can mitigate such problematic developments by correcting false authorities and by providing endorsement for unrecognized authorities. We conclude with a research agenda to study functional forms of epistemic authorities and epistemic intermediaries in the digital public sphere
Ethical memory and cinema: Confronting the past in Fatih Akın’s The Cut
Get PDFThis article aims to discuss the ethical–political responsibility of constructing a memory of 1915 through Fatih Akın’s The Cut (2014). The film explores the Armenian Genocide, which Turkey’s official historiography denies, and sparked heated debates on its release in Turkey. Based on the claim that constructing a memory of genocide is an ethical–political issue, I argue that The Cut’s aesthetic of remembrance fails to lead to an ethical questioning of historical denial and it thus leaves 1915 in the past. In order to discuss the film’s failure to fulfill its ethical responsibility, I explore the following questions: What is the ethical responsibility of remembering the devastating past? What does The Cut’s way of remembering 1915 accomplish and fail to accomplish in terms of ethical memory? By examining the limitations and possibilities of cinema in memory construction, this study seeks to contribute to discussions on the aesthetic and ethical dimensions of memory studies
Analyzing Atomic Interactions in Molecules as Learned by Neural Networks
Get PDFWhile machine learning (ML) models have been able to achieve unprecedented accuracies across various prediction tasks in quantum chemistry, it is now apparent that accuracy on a test set alone is not a guarantee for robust chemical modeling such as stable molecular dynamics (MD). To go beyond accuracy, we use explainable artificial intelligence (XAI) techniques to develop a general analysis framework for atomic interactions and apply it to the SchNet and PaiNN neural network models. We compare these interactions with a set of fundamental chemical principles to understand how well the models have learned the underlying physicochemical concepts from the data. We focus on the strength of the interactions for different atomic species, how predictions for intensive and extensive quantum molecular properties are made, and analyze the decay and many-body nature of the interactions with interatomic distance. Models that deviate too far from known physical principles produce unstable MD trajectories, even when they have very high energy and force prediction accuracy. We also suggest further improvements to the ML architectures to better account for the polynomial decay of atomic interactions
Quantitative Prediction of Protein–Polyelectrolyte Binding Thermodynamics: Adsorption of Heparin-Analog Polysulfates to the SARS-CoV-2 Spike Protein RBD
Get PDFInteractions of polyelectrolytes (PEs) with proteins play a crucial role in numerous biological processes, such as the internalization of virus particles into host cells. Although docking, machine learning methods, and molecular dynamics (MD) simulations are utilized to estimate binding poses and binding free energies of small-molecule drugs to proteins, quantitative prediction of the binding thermodynamics of PE-based drugs presents a significant obstacle in computer-aided drug design. This is due to the sluggish dynamics of PEs caused by their size and strong charge–charge correlations. In this paper, we introduce advanced sampling methods based on a force-spectroscopy setup and theoretical modeling to overcome this barrier. We exemplify our method with explicit solvent all-atom MD simulations of the interactions between anionic PEs that show antiviral properties, namely heparin and linear polyglycerol sulfate (LPGS), and the SARS-CoV-2 spike protein receptor binding domain (RBD). Our prediction for the binding free-energy of LPGS to the wild-type RBD matches experimentally measured dissociation constants within thermal energy, kBT, and correctly reproduces the experimental PE-length dependence. We find that LPGS binds to the Delta-variant RBD with an additional free-energy gain of 2.4 kBT, compared to the wild-type RBD, due to the additional presence of two mutated cationic residues contributing to the electrostatic energy gain. We show that the LPGS–RBD binding is solvent dominated and enthalpy driven, though with a large entropy–enthalpy compensation. Our method is applicable to general polymer adsorption phenomena and predicts precise binding free energies and reconfigurational friction as needed for drug and drug-delivery design
Upregulation of haematopoetic cell kinase (Hck) activity by a secreted parasite effector protein (Ta9) drives proliferation of Theileria annulata-transformed leukocytes
Get PDFReversible transformation of bovine leukocytes by the intracellular parasites Theileria annulata and Theileria parva is central to pathogenesis of the diseases they cause, tropical theileriosis and East Coast Fever, respectively. Parasite-dependent constitutive activation of major host transcription factors such as AP-1 (Activating Protein 1) and NF-κB (Nuclear Factor-Kappa B) sustains the transformed state. Although parasite interaction with host cell signaling pathways upstream of AP-1 have been studied, the precise contribution of Theileria encoded factors capable of modulating AP-1 transcriptional activity, and other infection-altered signaling pathways is not fully understood. We previously showed that the Ta9 protein from T. annulata (TA15705) is secreted into the host cell cytoplasm and contributes to infection-induced AP-1 transcriptional activity. The current study employed RNA-seq to investigate the ability of ectopically expressed Ta9 to modulate the gene transcription profile of a bovine macrophage cell line, BoMac. RNA-seq identified 560 (400 upregulated and 160 downregulated) differentially expressed genes. KEGG analysis predicted a high number of upregulated genes associated with carcinogenesis such as CCND1, CDKN1A, ETV4, ETV5, FLI1, FRA1, GLI2, GRO1, HCK, IL7R, MYBL1, MYCN, PIM1 and TAL1. Ta9 introduction also affected genes associated with proinflammatory processes such as cytokines, chemokines, growth factors and metalloproteinases. Enrichment analysis of differentially expressed genes revealed that Ta9 is potentially involved in activating other host cell signaling pathways in addition to those that lead to induction of AP-1. Comparing our data with data on differentially expressed BoMac genes modulated by the secreted TashAT2 factor of T. annulata identified the gene encoding the tyrosine protein kinase hematopoietic cell kinase (HCK) as common to both data sets. HCK is essential for the proliferation of T. parva-transformed B cells and herein, we demonstrate that enzymatic activity of HCK is also essential for T. annulata- and T. lestoquardi-transformed macrophage proliferation
“Open Sourcing” Workflow and Machine Learning Approaches for Attributing Obsidian Artifacts to Their Volcanic Origins: A Feasibility Study from the South Caucasus
Get PDFTraditionally, reliable obsidian sourcing requires expensive calibration standards and extensive geological reference collections as well as experience with statistical processing. In the South Caucasus — one of the most obsidian-rich regions on the planet — this combination of requirements has often restricted sourcing studies because few projects have geological reference collections that cover all known obsidian sources. To test an alternative approach, we conducted “open sourcing” using portable X-ray fluorescence (pXRF) analyses of geological specimens with three key changes to the conventional method: (1) commercially available calibration standards were replaced with a loanable Peabody-Yale Reference Obsidians (PYRO) set, (2) a comprehensive geological reference collection was replaced with a published dataset of consensus values (Frahm, 2023a, 2023b), and (3) processing in statistical packages was replaced with two semiautomated machine-learning workflows available online. For comparison, we used classification by-eye with JMP 17.2 statistical software. Furthermore, we propose a new method to evaluate calibrations, which streamlines comparisons and which we refer to as a symmetric difference ratio (SDR). The results of this feasibility study demonstrate that this “open sourcing” workflow is reliable, yet currently only in combination with classification by-eye. When the consensus values were combined with the machine-learning solutions, the classification results were unsatisfactory. The most encouraging aspect of our alternative “open sourcing” workflow is that it enables correct source identification without physically measuring reference collections, therefore surmounting an obstacle that, until now, has severely limited archaeological research. We anticipate that rapid developments in machine-learning will also soon improve the workflow
Coverages of HiRISE images by fan and blotch deposits
No full textThis dataset presents detailed coverage information derived from catalogs of CO₂ jet deposit features—fans and blotches—observed at the Martian South Pole. Generated using high-resolution HiRISE imagery from the Mars Reconnaissance Orbiter (MRO), the dataset quantifies the spatial extent and distribution of these seasonal deposits across multiple Martian years. The coverage data is crucial for understanding the dynamics of CO₂ sublimation and its interaction with surface and atmospheric processes.
The coverage metrics were calculated from annotated features compiled through contributions from the citizen science project Planet Four and advanced clustering algorithms. Each dataset entry includes coverage percentages, and the tile and image identifiers. The data spans several key regions of interest, providing insights into Martian polar processes.
This coverage dataset is a valuable resource for planetary scientists, climate modelers, and researchers focused on Martian seasonal dynamics and atmospheric coupling