Miracle-dz/UniFAR-FTUs huggingface dataset:
Temporal Variability of Fluvial Sand Composition: An Annual Time Series From Four Rivers in SW Germany

The sampling of fluvial sediment is subject to many sources of uncertainty, for example, time and location, and the number of samples collected. It is nevertheless commonly assumed that a sample taken at one time and location provides a somewhat averaged compositional signal. Any spatial or temporal variability of this signal is often neglected. This study investigates how the composition of bed load sand changes over an observation period of 1 year in four river basins with differing bedrock geology in southwestern Germany. Up to 12 bulk sediment samples were taken at the same locations using the same approach and analyzed for their granulometry and geochemistry. The results indicate that (a) different grain sizes yield different compositions due to source rock composition and hydraulic sorting effects, (b) bulk sediment composition changes temporally due to changing grain‐size distribution, and (c) compared to the bulk sample, the composition of narrow grain sizes is temporally more stable but nevertheless has an average variability of 15%. Because heavy mineral‐bound elements such as Zr have the highest variability, we relate a major component of compositional variability to temporally varying heavy mineral concentrations in response to hydrodynamic processes. Mixing modeling demonstrates that the fluvial sand faithfully reflects its catchment geology and that the sediment sources do not change substantially during the observation period, even during a flooding event. We conclude (a) that the causes for compositional variability may be disentangled using chemical and granulometric time series data and (b) that narrow grain sizes yield representative source rock contributions.
Classification of IR Images of Small Eruptions at the Erebus Volcano, Antarctica, With Zernike Moments and Support Vector Machine

To investigate the explosive nature of the Erebus volcano, Antarctica, millions of infrared images of the Ray lava lake were analyzed to identify time and position of non‐explosive small eruptions (NESEs). We developed a new technique based on two steps: (a) feature recognition using Zernike moments of the IR images and (b) classification using Support Vector Machine (SVM) applied to Zernike moments. Measures of the performance score were at least higher than 97% via different metrics for different categorization tasks. We observed distinctly different Zernike spectrums between NESEs and no‐eruption images. In the three months with the best quality images (December 2013, December 2014, and January 2015), out of about one million images per month, 654, 405, and 3,650 NESEs were detected, respectively. Using k‐means clustering three activity regimes emerged: low (≤4 NESEs per hour), intermediate (4
Cross‐Property Relationship Between Electrical Resistivity and Elastic Wave Velocity of Crustal Rocks From the Oman Drilling Project Hole GT3A: Implications for in Situ Geophysical Properties of Oceanic Crust

Geophysical properties of oceanic crust are strongly influenced by the presence of cracks. We studied the effects of cracks on the physical properties of oceanic crustal rocks collected from the ICDP Oman Drilling Project Hole GT3A. Electrical resistivity and P‐ and S‐wave velocities were measured under dry and brine‐water‐saturated conditions for each sample. The experimental results reveal that electrical resistivity and elastic wave velocities are differently correlated with porosity. We performed joint inversion of the measured electrical and elastic properties combining an effective medium model by Kachanov and a statistical crack fluid flow model by Guéguen and Dienes with percolation theory. As a result, the variations in electrical and elastic properties can be related to the crack microstructural parameters: crack density and aspect ratio, as well as connectivity of cracks evaluated from crack density. To understand the influence of in situ conditions of oceanic crust, the joint inversion using the proposed cross‐property relationship was performed for geophysical properties obtained by logging measurements at IODP Hole 1256D. Results show the depth variations of resistivity and sonic velocities can be successfully interpreted by decreasing crack porosity and connectivity. Our data and analysis can provide new insights into the interpretation of geophysical data from the oceanic crust at which pore‐fluid plays key roles in various geodynamic activities.
Reduction of Proinflammatory Effector Functions Through Remodeling of Fatty Acid Metabolism in CD8+ T Cells From Rheumatoid Arthritis Patients

Rheumatoid arthritis (RA) CD8+ T cells maintain their effector proinflammatory phenotype by changing their metabolism toward aerobic glycolysis. However, their massive energy and biosynthesis needs may require additional substrates other than glucose. Since systemic alterations in lipid metabolism have been reported in RA patients, we explored the role of fatty acid (FA) metabolism in CD8+ T cells to identify potential targets to curb their proinflammatory potential.
Cyanobacteria mitigation using low power ultrasound for gas vesicle collapse

The ability of a low‐power ultrasound system to alter the physiology of cyanobacteria cells in controlled field applications was evaluated. Serratia sp. , a model bacteria, and cyanobacteria collected from a bloom containing Microcystis sp. and Aphanizomenon sp. , were placed in sound transparent containers and exposed to ultrasound in field studies. No observed changes in Serratia sp. and cyanobacteria gas vesicles between unexposed controls and ultrasound exposed samples were found. Cell viability and phycocyanin concentration for both model bacteria and environmental samples were not significantly affected. At the highest acoustic pressure measured (3.5 kPa), 1 m from the transducer, the acoustic pressures were over 100× lower than gas vesicle critical collapse pressures. Moreover, the ultrasound frequencies emitted are significantly lower than gas vesicle resonance frequencies. Therefore, consistent with pressure and frequency measurements, we found no evidence that gas vesicle collapse is the mechanism of ultrasound as a cyanobacteria mitigation strategy.
Rheology of Hexagonal Close‐Packed (hcp) Iron

The viscosity of hexagonal close‐packed (hcp) Fe is a fundamental property controlling the dynamics of the Earth's inner core. We studied the rheology of hcp‐Fe using high‐pressure and ‐temperature deformation experiments with in situ stress and strain measurements. Experiments were conducted using D111‐type and deformation‐DIA apparatuses at pressures of 16.3–22.6 GPa, temperatures of 423–923 K, and uniaxial strain rates of 1.52 × 10−6 to 8.81 × 10−5 s−1 in conjunction with synchrotron radiation. Experimental results showed that power‐law dislocation creep with a stress exponent of n = 4.0 ± 0.3, activation energy of E* = 240 ± 20 kJ/mol, and activation volume of V* = 1.4 ± 0.2 cm3/mol is dominant deformation mechanism at >∼800 K, whereas a mechanism with power‐law breakdown prevails at lower temperatures. An extrapolation of the power‐law dislocation creep flow law based on homologous temperature scaling suggests the viscosity of hcp‐Fe under inner core conditions is ≥∼1019 Pa s. If this power‐law dislocation creep mechanism is assumed to be the dominant mechanism in the Earth's inner core, the equatorial growth or translation mode mechanism may be the dominant geodynamical mechanism causing the observed inner core structure.
Investigation of SLM Process in Terms of Temperature Distribution and Melting Pool Size: Modeling and Experimental Approaches

Selective laser melting (SLM) is an additive manufacturing (AM) technique that has the potential to produce almost any three-dimensional (3D) metallic part, even those with complicated shapes. Throughout the SLM process, the heat transfer characteristics of the metal powder plays a significant role in maintaining the product quality during 3D printing. Thus, it is crucial for 3D-printing manufacturers to determine the thermal behavior over the SLM process. However, it is a significant challenge to accurately determine the large temperature gradient and the melt pool size using only experiments. Therefore, the use of both experimental investigations and numerical analysis can assist in characterizing the temperature evaluation and the melt pool size in a more effective manner. In this study, 3D finite element analysis applying a moving volumetric Gaussian laser heat source was used to analyze the temperature profile on the powder bed and the resultant melt pool size throughout the SLM process. In the experiments, a TELOPS FAST-IR (M350) thermal imager was applied to determine the temperature profile of the melting pool and powder bed along the scanning direction during the SLM fabrication using Ti6Al4V powder. The numerically calculated results were compared with the experimentally determined temperature distribution. The comparison showed that the calculated peak temperature for single- and multi-track by the developed thermal model was in good agreement with the experiment results. Secondly, the developed model was verified by comparing the melting pool size for various laser powers and scanning speeds with the experimentally measured melting pool size from the published literature. The developed model could predict the melt pool width (with 2–5% error) and melt pool depth (with 5–6% error).
The Föllmer–Schweizer decomposition under incomplete information

In this paper we study the Föllmer–Schweizer decomposition of a square integrable random variable with respect to a given semimartingale S under restricted information. Thanks to the relationship between this decomposition and that of the projection of with respect to the given information flow, we characterize the integrand appearing in the Föllmer–Schweizer decomposition under partial information in the general case where is not necessarily adapted to the available information level. For partially observable Markovian models where the dynamics of S depends on an unobservable stochastic factor X, we show how to compute the decomposition by means of filtering problems involving functions defined on an infinite-dimensional space. Moreover, in the case of a partially observed jump-diffusion model where X is described by a pure jump process taking values in a finite dimensional space, we compute explicitly the integrand in the Föllmer–Schweizer decomposition by working with finite dimensional filters. Finally, we use our achievements in a financial application where we compute the optimal hedging strategy under restricted information for a European put option and provide a comparison with that under complete information.
Depth Moderates DOC Impact on Cold‐Water Refugia in Small, Northern Temperate Lakes

Widespread changes in dissolved organic carbon (DOC) concentrations in lakes of the Northern Hemisphere are well documented, and there is a need to understand the ecological implications for changes in cold‐water refugia. DOC controls thermal structure in small, wind‐sheltered lakes, thus influencing the volume and persistence of the hypolimnion and cold‐water habitat. We explored the relationship between the quantity and quality of DOC and the availability of cold‐water habitat over the course of summer stratification in small lakes of varying depths. The ratio of the hypolimnetic volume to total lake volume was calculated to assess the relative changes in cold‐water habitat availability in each lake over time. DOC concentration, maximum lake depth, and the interaction between DOC concentration and maximum lake depth explained 87% of the variability in percent change in hypolimnion volume ratio across studied lakes. Hypolimnion compression was greater in shallow, low DOC lakes, whereas deeper, intermediate DOC lakes had more persistent hypolimnion volumes over the course of summer stratification. These results demonstrate that depth moderates the effect of DOC on the volume and persistence of cold‐water refugia availability in north temperate lakes, advancing our understanding of differing lake sensitivity in a rapidly changing physical and chemical environment.
Processing and Validation of FORMOSAT‐7/COSMIC‐2 GLONASS Total Electron Content Observations

The Formosa Satellite‐7/Constellation Observing System for Meteorology, Ionosphere, and Climate‐2 (FORMOSAT‐7/COSMIC‐2, F7/C2) Tri‐GNSS Radio Occultation System observes both Global Positioning System (GPS) and GLObalnaya NAvigazionnaya Sputnikovaya Sistema (GLONASS) slant total electron content (TEC). Space‐based TEC observations have historically relied on GPS signals, and the processing methodologies and data quality of GLONASS absolute TEC observations are thus less well established. We present a description of the differences in the processing for the F7/C2 GLONASS absolute TEC observations. This primarily entails estimation of a paired receiver‐transmitter differential code bias, which is needed due to the GLONASS usage of frequency‐division multiple access. We additionally perform a validation of the F7/C2 GLONASS absolute TEC observations through comparison with colocated F7/C2 GPS absolute TEC observations. Based on this comparison, we estimate the GLONASS absolute TEC error to be ∼2.6 TEC units (TECU), which is similar to previous estimates of the F7/C2 GPS absolute TEC error (∼2.5 TECU). This demonstrates that the F7/C2 GLONASS absolute TEC observations are generally similar in quality to the F7/C2 GPS absolute TEC observations, and are suitable for use by the operational and scientific communities.
Long‐Term Observations of Levoglucosan in Arctic Aerosols Reveal Its Biomass Burning Source and Implication on Radiative Forcing

Biomass burning (BB) has a significant influence on the Arctic environment. Here, we determined the atmospheric levels of BB‐specific tracer compounds such as levoglucosan (Lev), galactosan (Gan), and mannosan (Man) in Arctic aerosols during 2010–2018. The average concentrations of Lev during the study period ranged between 0.43 and 4.15 ng m−3. Both Lev/Man (0–30) and Man/Gan (0–3) ratios further suggested their origin from softwood/hardwood burning. The North Atlantic Oscillation (NAO) was the main driver of the Lev variability during the study period and Lev could be advected to Arctic air during the NAO was in a positive phase. Based upon the levels of Lev, black carbon (BC) generated from BB was estimated, and the corresponding radiative forcing was then calculated by Santa Barbara DISORT Atmospheric Radiative Transfer. BC has a potential warming effect in the atmosphere (+4.28 W/m2) while shows a cooling effect on the surface, which is equivalent to a large volcanic eruption (−3 W/m2). Since climate change is expected to intensify BB around the Arctic, such BC aerosols should be considered in future climate model projections.
In Situ Estimation of Erosion Model Parameters Using an Advection‐Diffusion Model and Bayesian Inversion

We describe a framework for the simultaneous estimation of model parameters in a partial differential equation using sparse observations. Markov Chain Monte Carlo sampling is used in a Bayesian framework to estimate posterior probability distributions for each parameter. We describe the necessary components of this approach and its broad potential for application in models of unsteady processes. The framework is applied to three case studies, of increasing complexity, from the field of cohesive sediment transport. We demonstrate that the framework can be used to recover posterior distributions for all parameters of interest and the results agree well with independent estimates (where available). We also demonstrate how the framework can be used to compare different model parameterizations and provide information on the covariance between model parameters.
Observationally Constrained Modeling of Peroxy Radical During an Ozone Episode in the Pearl River Delta Region, China

Peroxy radicals (RO2* = HO2 + RO2) play key roles in forming secondary air pollutants such as ozone, yet model underprediction of RO2* is a challenging radical closure problem. In this study, RO2* were measured by a dual‐channel peroxy radical chemical amplification system during an ozone episode in October 2018 at an urban site in the Pearl River Delta region, China. The box model based on the Master Chemical Mechanism severely underpredicted RO2* levels, particularly at night and under high nitric oxide (NO) conditions. The observed‐to‐modeled ratio of RO2* increased from ∼3 under 1 ppbv NO to ∼46 under >10 ppbv NO with a missing RO2* source up to 5.8 ppbv hr−1. Observation data were used to constrain model predictions, and the results reveal that constraining nitrous acid (HONO) or glyoxal/methylglyoxal could not improve predictions, while constraining nitrate radicals (NO3) or other oxygenated volatile organic compounds (OVOCs), particularly phenolic compounds and improvements in their gas‐phase mechanisms, could more effectively increase model‐simulated RO2* concentrations. When OVOCs, NO3, and HONO were constrained, the simulated RO2* concentrations increased to the greatest extent with an observed‐to‐modeled RO2* ratio of 1.9 during the day and 1.3 at night, mainly due to the interaction between OVOCs and NO3 radicals. As the underestimated NO3 levels and the unmeasured reactive organic gases, as well as their unknown oxidation mechanisms, are among the major reasons for the underestimation of RO2*, upgraded atmospheric chemistry involving more OVOC species and more accurate NO3 would improve model‐simulated RO2* concentrations, especially during nighttime.
Ligand-Binding-Site Structure Shapes Allosteric Signal Transduction and the Evolution of Allostery in Protein Complexes

Abstract The structure of ligand-binding sites has been shown to profoundly influence the evolution of function in homomeric protein complexes. Complexes with multichain binding sites (MBSs) have more conserved quaternary structure, more similar binding sites and ligands between homologs, and evolve new functions slower than homomers with single-chain binding sites (SBSs). Here, using in silico analyses of protein dynamics, we investigate whether ligand-binding-site structure shapes allosteric signal transduction pathways, and whether the structural similarity of binding sites influences the evolution of allostery. Our analyses show that: 1) allostery is more frequent among MBS complexes than in SBS complexes, particularly in homomers; 2) in MBS homomers, semirigid communities and critical residues frequently connect interfaces and thus they are characterized by signal transduction pathways that cross protein–protein interfaces, whereas SBS homomers usually not; 3) ligand binding alters community structure differently in MBS and SBS homomers; and 4) except MBS homomers, allosteric proteins are more likely to have homologs with similar binding site than nonallosteric proteins, suggesting that binding site similarity is an important factor driving the evolution of allostery.
Flat rotation curves and a non-evolving Tully-Fisher relation from KMOS galaxies at z~1

The study of the evolution of star-forming galaxies requires the determination of accurate kinematics and scaling relations out to high redshift. In this paper, we select a sample of 18 galaxies at z~1, observed in the H-alpha emission-line with KMOS, to derive accurate kinematics using a novel 3D analysis technique. We use the new code 3D-Barolo, that models the galaxy emission directly in the 3D observational space, without the need to extract kinematic maps. This technique's major advantage is that it is not affected by beam smearing and thus it enables accurate determination of rotation velocity and internal velocity dispersion, even at low spatial resolution. We find that: 1) the rotation curves of these z~1 galaxies rise very steeply within few kiloparsecs and remain flat out to the outermost radius and 2) the H-alpha velocity dispersions are low, ranging from 15 to 40 km/s, which leads to V/sigma = 3-10. These characteristics are remarkably similar to those of disc galaxies in the local Universe. Finally, we also report no evolution of the Tully-Fisher relation, as our sample lies precisely on the same relation of local spiral galaxies. These findings are more robust than those obtained with previous methods because of our 3D approach. Two-dimensional techniques with partial or absent corrections for beam smearing can systematically lead to the overestimation of velocity dispersions and underestimation of rotation velocities, which result in the inaccurate placement of galaxies in the Tully-Fisher diagram. Our results show that disc galaxies are kinematically mature and rotation-dominated already at z~1.
Flagellar switch inverted repeat sequence variation impacts Clostridioides difficile RT027/MLST1 virulence

The impact of Clostridioides difficile strain diversity on the severity of intestinal infection and diarrhea remains unclear. The RT027/ST1 strain is highly prevalent and has been associated with more severe disease and increased toxin production. Previous studies using antibiotic-treated mice, however, have demonstrated that the severity of diarrhea and colonic inflammation caused by clinical RT027/ST1 C. difficile isolates cultured from different patients is isolate-specific and varies from avirulent to lethal. Herein we demonstrate that increased flagellar expression is associated with increased in vivo virulence. While sequencing the flagellar operon did not identify differences between high and low virulence isolates, high virulence was associated with strains encoding higher proportions of the phase variable flagellar switch in the ON mode. We found that the proportion of bacteria with the switch in the ON mode correlates with maximum weight loss, a readout for virulence in mice. Further analysis of flagellar switch sequences identified variant inverted repeat (IR) sequences, with 40% of isolates having lost one A or T in the IR compared to the genome of C. difficile R20291. The isolates with the R20291 IR sequence have increased virulence compared to those with variant IR (p = 3.2e-05) and these isolates have markedly reduced ability to invert the flagellar switch. Our results suggest that a restricted capacity to invert the flagellar switch during infection is associated with reduced virulence of C. difficile RT027/ST1 strains and may account for some of the inconsistent associations between C. difficile infection and disease severity in patients. IMPORTANCE C. difficile RT027/ST1 has been associated with high virulence. However, variable virulence among ST1 isolates has also been observed. Recent studies have shed light on the impacts of the gut microbiota and host immunity during Clostridioides difficile infection (CDI). Beyond that, determining the genetic factors of C. difficile regulating virulence is essential for a successful CDI diagnosis and treatment. Here, we report a strong association between the flexibility of the flagellar switch and the virulence of C. difficile. Specifically, the inverted repeats of the flagellar switch correlate with switch flexibility. Overall, our study explores variations in C. difficile virulence and highlights the potential of using flagellar switch inverted repeats as an easily accessible genetic trait to predict pathogen virulence.