Eli Asikin-Garmager, Yu-Ming Liou, Caroline Myrick
et al.
Wikipedia administrators are vital to the platform's success, performing over a million administrative actions annually. This multi-method study systematically analyzes adminship across 284 Wikipedia languages since 2018, revealing a critical two-sided trend: while over half of all Wikipedias show a net increase in administrators, almost two-thirds of highly active Wikipedias face decline. Our analysis, drawing from large-scale adminship log analysis, over 3000 surveys, and 12 interviews, reveals this decline is primarily driven by insufficient recruitment, not unusual attrition. We identify key barriers for potential administrators, including limited awareness, ambiguous requirements, a demanding selection process, and low initial interest. Recognizing that current administrators remain highly motivated and engaged, we propose actionable recommendations to strengthen recruitment pipelines and fuel Wikipedia administrator growth, crucial for Wikipedia's long-term sustainability.
Machine-learned interatomic potentials (MLIPs) have rapidly progressed in accuracy, speed, and data efficiency in recent years. However, training robust MLIPs in multicomponent systems still remains a challenge. In this work, we train a MLIP to describe hydrated Nafion ionomers and platinum catalysts, which are important components of fuel cells, by constructing a diverse training set to describe the bulk polymer and interfacial catalyst-polymer interactions well. We find that active learning improves the initial dataset little in terms of reducing uncertainty and error, pointing towards a need for more effective methods to efficiently explore the relevant interactions in complex, multicomponent systems. We use our trained MLIP to study the properties of the platinum-Nafion system, including polymer structure, proton mobility in a bulk Nafion polymer and near a platinum-Nafion interface, and reactions near and far from the interface, finding excellent results for structure and reactions contained within our training set. Transport seems well described, with both vehicular transport and Grotthuss hopping captured, although converged calculations of diffusivities were not computed because they require calculations of tens of nanoseconds that are challenging with current state-of-the-art MLIPs. The combined insights that this model provides can be leveraged to optimize fuel cell performance, and the approach can be applied to other chemical processes and devices where structure, transport, and reactivity all contribute to overall observed performance.
Vivek P. Jani, Edwin J. Yoo, Aleksandra Binek
et al.
Background Heart failure with preserved ejection fraction (HFpEF) constitutes more than half of all HF but has few effective therapies. Recent human myocardial transcriptomics and metabolomics have identified major differences between HFpEF and controls. How this translates at the protein level is unknown. Methods and Results Myocardial tissue from patients with HFpEF and nonfailing donor controls was analyzed by data‐dependent acquisition (n=10 HFpEF, n=10 controls) and data‐independent acquisition (n=44 HFpEF, n=5 controls) mass spectrometry‐based proteomics. Differential protein expression analysis, pathway overrepresentation, weighted coexpression network analysis, and machine learning were integrated with clinical characteristics and previously reported transcriptomics. Principal component analysis (data‐dependent acquisition‐mass spectrometry) found HFpEF separated into 2 subgroups: one similar to controls and the other disparate. Downregulated proteins in HFpEF versus controls were enriched in mitochondrial transport/organization, translation, and metabolism including oxidative phosphorylation. Proteins upregulated in HFpEF were related to immune activation, reactive oxygen species, and inflammatory response. Ingenuity pathway analysis predicted downregulation of protein translation, mitochondrial function, and glucose and fat metabolism in HFpEF. Expression of oxidative phosphorylation and metabolism genes (higher) versus proteins (lower) was discordant in HFpEF versus controls. Data‐independent acquisition‐mass spectrometry proteomics also yielded 2 HFpEF subgroups; the one most different from controls had a higher proportion of patients with severe obesity and exhibited lower proteins related to fuel metabolism, oxidative phosphorylation, and protein translation. Three modules of correlated proteins in HFpEF that correlated with left ventricular hypertrophy and right ventricular load related to (1) proteasome; (2) fuel metabolism; and (3) protein translation, oxidative phosphorylation, and sarcomere organization. Conclusions Integrative proteomics, transcriptomics, and pathway analysis supports a defect in both metabolism and translation in HFpEF. Patients with HFpEF with more distinct proteomic signatures from control more often had severe obesity, supporting therapeutic efforts targeting metabolism and translation, particularly in this subgroup.
Diseases of the circulatory (Cardiovascular) system
Lis Corral-Gómez, Octavio Armas, Francisco Moya-Fernández
et al.
The evolution of the main macroscopic parameters that characterize spray formation for three different fuels is studied by means of the Schlieren visualization technique. The annalized fuels comprise a fossil diesel fuel, used as reference, and two neat low carbon liquid 100% paraffinic fuels: a gas-to-liquid (GtL) and a hydrotreated vegetable oil (HVO). Additionally, the paper exposes the behavior of fuels autoignition for different injection pressures and start of energizing (SoE), for prescribed thermodynamic variables inside the engine cylinder. The experimental results obtained at the beginning of the injection process are compared with results from known models of penetration and cone angle of the fuel spray under non-evaporative conditions. These conditions are chosen to match those of the diesel engines used in surveillance light aircraft such as small helicopters. This work presents two important novelties: (i) the application of an automatic image analysis procedure (previously published) to the fuel injection process and (ii) the comparison of different fuels, regarding their effect on the injection process and the start of combustion. This is done under complete replacement of fossil fuel by two 100% paraffinic fuels. The most important results are the following: i) Compared to GtL and Diesel fuels, the HVO fuel has shorter ignition delay. This result could be attributed to its higher cetane number. ii) However, in most of the tested cases, in addition to a slightly longer spray penetration of the HVO fuel, its cone angle is also slightly wider than that of the other two fuels. This result would be collaborating in the development of a wider spray surface during the evolution of the spray lift off and beyond. This leads to a better air entrainment, and, in consequence, to produce an additional shortening of the ignition delay compared to the other two fuels. These findings would facilitate the fine tuning of modern engine technology for a progressive introduction of mentioned low carbon fuels in light aircraft such as unmanned helicopters for surveillance.