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Vaccine diplomacy: The politics of COVID-19 vaccines in Zimbabwe
No full textCOVID-19 vaccines were unevenly distributed across the world, with fewer supplies in the Global South. The geopolitical powers who developed the vaccines started engaging in vaccine diplomacy, competing to donate or export their vaccines to other countries. A perspective neglected in this landscape is of those living in countries targeted by vaccine diplomacy. This study conducted a survey experiment in Zimbabwe to examine the influence of vaccine origins on vaccination intention. The results suggest that vaccine country origins and country image interact to influence vaccination intention toward American and Chinese vaccines. We also found that there was an interaction effect between vaccine country origins and partisanship in relation to Chinese vaccines. The findings suggest that the utility of vaccine diplomacy as a soft power strategy is affected by the heterogeneity of a country’s image fostered through international and local politics
Ginkgo: A Learned Index Enhanced Tiered Memory System
No full textCompute Express Link (CXL), as an emerging high-speed interconnect protocol, offers a promising approach to memory expansion. Organizing fast DDR DRAM and large CXL memory as a tiered memory system is preferred to obtain the large memory capacity while maintaining high memory performance. Additionally, such a tiered memory system also adopts huge pages to alleviate address translation overhead. However, due to memory bloating issues in huge pages, existing hardware-based tiered memory management systems suffer from severe cache conflicts and DDR DRAM underutilization, resulting in significant performance degradation. We introduce Ginkgo, a learned-index enhanced tiered memory system, which builds a distribution-aware cache index mechanism while leveraging the learned index to minimize metadata overhead. Evaluation reveals that Ginkgo reduces average memory access latency with an average of 3.1% and 13.5% compared to state-of-the-art Alloy Cache and Unison Cache, respectively
The Role of Calcium Phosphate Nanoparticles in Dental Materials: Properties, Applications, and Future Prospects
No full textCalcium phosphate nanoparticles (CaP NPs) have gained substantial attention in dental research due to their ability to mimic the natural mineral compo sition of teeth and bones. This manuscript explores the critical properties of CaP NPs, their applications in various dental materials, and the future prospects of these nanoparticles in dentistry. CaP NPs have been incorporated into restorative mate rials, dental adhesives, and protective coatings, where they enhance mechanical strength, promote remineralization, and offer improved biocompatibility. The study also discusses the challenges associated with integrating CaP NPs into dental prod ucts and outlines the future research directions needed to fully harness their potential in clinical dentistry
Specialized insectivores drive differences in avian community composition between primary and secondary forest in Central Africa
No full textThe human population of sub-Saharan Africa is projected to triple by 2100, drastically increasing anthropogenic pressure on biodiversity. When rainforest is disturbed by anthropogenic drivers, species respond heterogeneously; these patterns have rarely been quantified for Congo rainforest fauna. Our objective was to understand how community composition changed with human disturbance—with particular interest in the guilds and species that indicate primary rainforest. At a long-term bird banding site on mainland Equatorial Guinea, we captured over 3200 birds across 6 field seasons in selectively logged secondary forest and in largely undisturbed primary forest. Our multivariate ordination indicated a significant split between primary and secondary forest communities. We caught 47% fewer birds in secondary forest overall, with Dorylus ant-followers, mixed-species flockers and terrestrial insectivores showing at least two-fold reductions. We identified 12 species that were characteristic of primary forest. Of those, 10 were strict insectivores: terrestrial insectivores (Sheppardia cyornithopsis, Illadopsis cleaveri, I. fulvescens/rufipennis), mixed-flockers (Phyllastrephus icterinus/xavieri, Elminia nigromitrata, Terpsiphone rufiventer, Pardipicus nivosus, Deleornis fraseri), ant-followers (Alethe castanea, Chamaetylas poliocephala), White-bellied Kingfisher (Corythornis leucogaster), and Blue-headed Wood Dove (Turtur brehmeri). Only the kingfisher Ispidina lecontei was captured more in secondary forest. This contributes to a growing body of Pantropical literature suggesting that insectivores living on or near the forest floor are vulnerable to rainforest degradation. Notably, few species disappeared entirely in secondary forest (unlike patterns seen in the Neotropics); rather, capture rates of 12 of 30 species (40%) were significantly reduced relative to primary forest. By understanding disturbance-sensitive guilds and species, we might identify the proximate mechanisms responsible for the loss of Afrotropical birds, thus helping to manage communities as forest disturbance continues
Investigation of Isobaric Mixing as a Mechanism for Boundary-Layer Cloud Formation
Get PDFThis study investigates the potential role of isobaric mixing in the formation of marine boundary layer clouds. Cloud formation theory emphasizes uplift and adiabatic cooling, but recent observations support the existence of small clouds forming at various altitudes, even below the lifting condensation level. Isobaric mixing of air with different thermodynamic properties can generate localized supersaturation. A Gaussian mixing model is employed to simulate this process, considering the correlation between temperature and water vapor. Cloud droplet size distributions from aircraft measurements show a persistent and prominent mode of small droplets at 9 (Formula presented.) m, and the size of this mode compares favorably with predictions from the model. The results suggests that isobaric mixing plausibly contributes to the formation of clouds, particularly those observed at multiple altitudes with narrow droplet size distributions. This finding highlights the importance of considering isobaric mixing processes in understanding and modeling cloud formation
The PAX3-FOXO1 Fusion Gene Reduces cell-ECM Interactions and TGFβ Signaling in rhabdomyosarcoma
No full textWe identify downregulation of genes related to cell-ECM interactions and TGFβ signaling in FPRMS. We confirm that TGFβ signaling enhances cell-ECM interactions in FNRMS, utilizing confocal reflection microscopy to assess ECM remodeling, and a live-cell sensor to quantitatively assess TGFβ signaling. We also show that PAX3-FOXO1 increases NOS1 expression, stimulating nitric oxide synthesis, which inhibits TGFβ signaling and reduces cell-ECM interactions. We suggest that PAX3-FOXO1 reprograms ECM anchorage dependence by suppressing cell-ECM interactions. The fusion gene can determine sensitivity to growth inhibition via targeted disruption of cell-ECM interactions or TGFβ signaling. Reduced anchorage reliance by the gene may allow cells to survive in circulation and enhance FPRMS metastatic potential
On-Vehicle Optimum Route Selection for a Plug-In Hybrid Electric Vehicle
No full textThis paper presents a methodology to optimally select between routes proposed by mapping software. The objective of the optimization is to make the best trade-off between travel time and energy consumption when deciding between different routes. The method uses an Intelligent driver model to convert the data from the mapping software into a vehicle speed & torque profile, then uses a reduced order energy model to find the vehicle energy consumption for each route. Weightings are applied to the difference in energy and travel time for each route compared to the primary route. The vehicle used in this investigation is the Stellantis Pacifica PHEV. Results support energy savings of up to 20% compared to the primary route, which depends on the routes and initial battery State of Charge (SOC)
Superlattice-Induced Superfluorescence in Quasi-2D Metal Halide Perovskites
No full textThis paper reports the role of the superlattice (crystal) structure of the quasi-two-dimensional (2D) perovskite (PEA2(FAPbBr3)n-1PbBr4) in room-temperature superfluorescence. Through steady-state and time-resolved spectroscopy, we observe a narrow spectral width, a quadratic emission dependence on the excitation fluence, and a burst of emission after a time delay in quasi-2D perovskite, key indicators of superfluorescence. Notably, bulk three-dimensional (3D) perovskite (FAPbBr3) does not demonstrate these features, suggesting that the quasi-2D structure containing superlattices is a requirement for superfluorescence. The formation of superlattices in quasi-2D perovskite thin films was confirmed using scanning transmission electron microscopy (STEM). These results suggest that the search for new superfluorescent materials should prioritize exploring analogous materials with well-defined superlattice structures
Unlocking the potential of sepiolite: Designing high-performance energy storage materials
No full textSepiolite, with its unique microporous structure, high specific surface area, excellent thermal stability, and chemical stability, has significant potential for application in the field of energy storage. However, a systematic summary of its application in key components of secondary batteries, such as electrodes, separators, and solid electrolytes, is lacking. This review aims to provide a comprehensive overview of the applications of natural fibrous magnesium silicate mineral-sepiolite and its composites in energy storage and conversion, focusing particularly on lithium-ion batteries (LIBs), lithium-sulfur batteries (LSBs), zinc-ion batteries (ZIBs), and fuel cells. We have reviewed various preparation methods for sepiolite-based composite materials and discussed their applications in the field of energy storage. This review particularly emphasizes the impact of structural regulation on the electrochemical performance of sepiolite and explores the process requirements for the large-scale fabrication of sepiolite composite materials. Our work indicates that sepiolite itself possesses certain energy storage capabilities, and the preparation of composite nanomaterials through solid-phase methods can significantly enhance the electrochemical performance of sepiolite. By utilizing sepiolite\u27s morphological and structural characteristics, the composite materials not only inherit the form of sepiolite but also achieve a significant enhancement in electrochemical performance. Nevertheless, the regulatory mechanism of sepiolite\u27s electrochemical performance is not yet fully understood, which points the way for future research. Future studies should focus on the structural regulation of sepiolite and the development of large-scale preparation processes, in order to widely apply it in high-performance energy storage systems