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Transitioning from hydrothermal carbonization to humification for producing artificial humic substances
Get PDFHydrothermal humification (HTH) is an emerging green route for converting biomass into artificial humic substances (A-HS), oxygen-rich macromolecules resembling natural humics and relevant for carbon sequestration and soil improvement. HTH represents the alkaline version of hydrothermal carbonization (HTC), acidic and yielding to insoluble hydrochars. Here, we investigate the pathways behind this transition by treating glucose, cellulose, and lignin at 220 °C for 4 h under controlled concentrations of alkali (KOH). Under HTH, carbohydrates undergo retro-aldol cleavage, yielding low solid yields and lactic acid and aldehydes that condense into phenolic/aromatic A-HS, as shown by solid-state NMR. In contrast, HTC mainly forms furanic hydrochars. Lignin under HTH undergoes near-complete depolymerization/defragmentation (<1.1 % residue), yielding oxygen-rich aromatic A-HS, whereas it remains unreacted under HTC. Overall, the resulting A-HS are aromatic, rich in oxygenated functionalities, and fluorescent, resembling natural HS and highlighting the potential of HTH for producing soil-relevant humics from biomass
Thermal stability of multi-fiber tungsten fiber-reinforced tungsten composites and their mechanical integrity after high temperature annealing
No full textExceptionally high carbon fixation and nitrogen assimilation rates in microbial mats of an alkaline soda lake
No full textAlkaline soda lakes, characterized by high pH and high concentrations of sodium and dissolved carbonates, support diverse alkaliphilic microbial communities. Using stable isotope probing with 13C-bicarbonate, 15N-ammonium, 15N-nitrate, and 15N-urea, we measured assimilation rates for carbon and nitrogen by microbial mats of alkaline Goodenough Lake, Canada. Our results showed extremely high carbon fixation rates averaging 24 g C/m2/day, equalling or exceeding rates measured fifty years ago in African alkaline soda lakes. Urea consumption occurred both during the day and during the night, but assimilation mainly occurred during the day. Ammonium assimilation was stable between day and night. Apparently, cyanobacteria preferred urea as a nitrogen source, whereas heterotrophs preferred ammonium. Two different cyanobacteria dominated the microbial mats, Nodosilinea and Sodalinema. Using Orbitrap mass spectrometry, we only observed assimilation of 13C bicarbonate by Sodalinema, but not by Nodosilinea. The latter might focus on different carbon sources, such as urea. Strong negative correlation between their abundances in proteomes also supported niche partitioning between these two cyanobacteria
The social sources adolescents consult for daily life choices: Variations in age and decision domains
No full textNeural network-based surrogate model for 3D edge-plasma transport in the standard configuration of W7-X
No full textConfidence-weighted integration of human and machine judgments for superior decision-making
No full textLarge language models (LLMs) can surpass humans in certain forecasting tasks. What role does this leave forhumans in the overall decision process? One possibility is that humans, despite performing worse than LLMs,can still add value when teamed with them. A human and machine team can surpass each individual teammate when team members’ confidence is well calibrated and team members diverge in which tasks they finddifficult (i.e., calibration and diversity are needed). We simplified and extended a Bayesian approach tocombining judgments using a logistic regression framework that integrates confidence-weighted judgmentsfor any number of team members. Using this straightforward method, we demonstrated its effectiveness inboth image classification and neuroscience forecasting tasks. Combining human judgments with one ormore machines consistently improved overall team performance. Our hope is that this simple and effectivestrategy for integrating the judgments of humans and machines will lead to productive collaborations.HIGHLIGHTS• Requirements for effective human-AI teaming, even when AI exceeds human capabilities• Scalable approach combining confidence-weighted judgments from humans and AI• Human-AI teaming surpassed individual AI systems in two different forecasting tasks• Adding a human to a team with one or more AI systems improved team performanceTHE BIGGER PICTUREArtificial intelligence (AI) systems, such as large language models (LLMs), have emerged as powerful tools in various domains. Recent studies have shown that LLMs can surpass humans in certain tasks, such as predicting the outcomes of neuroscience studies. This raises a critical question: as AI systems achieve superhuman performance in specific domains, will they displace human judgment in critical decision-making processes? Our study shows that humans still have a lot to offer. Because humans tend to make different mistakes than machines and can express how confident they are in their decisions, human judgments can be combined with those of AI systems to form teams that are more effective than teams consisting of machines alone. At least in the near term, human judgments offer a valuable and complementary signal that can increase decision-making performance in human-machine teams or ensembles
A natural history of the global Habsburg empire: Indian mongooses and the production, circulation and management of animal knowledge in the adriatic periphery
No full textABSTRACT OF THE BOOKWithin the Habsburg Empire of the late nineteenth century, nature became a central focus of political, economic, and scientific attention. A source of valuable natural resources and a platform for consolidating wider, territorial rule, its management and control was subsumed into a broader system of imperial governance. In this exacting analysis of the correlation between the environment and power, Habsburg Natures explores how the natural world fundamentally shaped the political and economic landscape within the Austro-Hungarian Empire from 1850 to 1918. Ranging from forestry and coal-mining to river politics and natural disasters, this volume spotlights how deeply intertwined the histories of environmentalism and empire are
Functional characterization of pathogenic SATB2 missense variants identifies distinct effects on chromatin binding and transcriptional activity
No full textSATB2-associated syndrome is an autosomal dominant neurodevelopmental syndrome caused by genetic alterations in the transcription factor SATB2. The associated phenotype is variable, and genotype-phenotype correlation studies have not yet been able to explain differences in severity and symptoms across affected individuals. While haploinsufficiency is the most often described disease mechanism, with the majority of variants consisting of whole- or partial-gene deletions and protein truncating variants with predicted loss-of-function, approximately one-third of affected individuals carry a SATB2 missense variant with an unknown effect. In this study, we sought to functionally characterize these missense variants to uncover associated pathogenic mechanisms. We combined a set of human cell-based experiments to screen 31 etiological SATB2 missense variants for effects on nuclear localization, global chromatin binding, and transcriptional activity. Our data indicate partial loss-of-function effects for most of the studied missense variants, but identify at least eight variants with increased SATB2 function showing a combination (or subset) of features that include stronger co-localization with DNA, decreased nuclear protein mobility suggesting increased overall chromatin binding, and maintained or increased transcriptional activity. These results demonstrate that phenotypes associated with variants in SATB2 may have distinct underlying disease mechanisms, and the data could provide a resource for future studies investigating disease variability and potential therapies for this condition
Persulfidation alters gene regulatory programs and promotes endothelial specification
No full textEndogenously generated sulfides are conserved among species and tissues and exert multiple effects through diverse mechanisms. Although sulfides have been linked to cell fates, their role in pluripotent stem cell commitment remains unknown. Here we discovered that during directed differentiation of induced pluripotent stem cells, endogenous sulfide levels drop in all three germ layers, with the mesodermal lineage exhibiting the lowest capacity to generate these species at early specification events. Addition of a rapid releasing sulfide donor in iPSCs or mesodermal cells did not affect the redox surveillance mechanisms, however, it altered persulfidation and transcription of cell fate commitment pathways. In particular, sulfide supplementation in pluripotent stem cells reduced cell differentiation processes by preserving the activity of the stem cell transcription factors OCT4. In contrast, supplementation of sulfide during mesodermal lineage specification promoted persulfidation and activated the WNT signaling as well as enriched the activity of the ETS transcription factor family, resulting in increased transcription of angiogenic and vessel morphogenesis genes. Sulfide addition during the development of vascular organoids enhanced blood vessel morphogenesis. Taken together, these data position protein persulfidation as a timing-dependent regulator that preserves pluripotency prior to commitment but subsequently biases mesoderm toward endothelial specification, thereby emerging as a tractable redox modification for engineering stem cell fate and vascularization
Nanobubble nucleation dynamics in reacting microdroplets: Insights from confocal laser scanning microscopy and molecular dynamics simulations
No full textGas-evolving interfacial reactions in microdroplets underpin processes in catalysis, energy conversion, and microreactor technologies, yet the principles of nanobubble nucleation remain unclear. Here, we integrate confocal laser scanning microscopy with coarse-grained molecular dynamics simulations to elucidate hydrogen nanobubble formation during base-catalyzed reactions of liquid organic hydrogen carrier (LOHC) droplets with aqueous NaOH. We reveal a competition-controlled nucleation mechanism governed by gas production rate, asymmetric solubility in droplet and surrounding phases, and water-gas interfacial tension. Nucleation occurs only when local gas concentrations exceed a critical threshold that is largely independent of production rate but strongly influenced by gas solubility in two phases. High production rates shorten induction times and shift nucleation toward the LOHC-water boundary, whereas increased solubility in LOHC or water suppresses nucleation, raising the critical threshold or extracting gas from the droplet. Reduced interfacial tension lowers the nucleation barrier, accelerates onset, and favors interfacial nucleation. These findings establish principles for controlling gas evolution in reactive emulsions, offering design guidelines for interfacial microreactors and nanobubble-enabled catalytic systems