bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pn Anisotropic Tomography of Northeast Asia: New Insight Into Subduction Dynamics and Volcanism
Authors: Du Mofei , Lei Jianshe , Zhao Dapeng , Lu Hongbin 
Published: January 2022

AbstractWe present a new high‐resolution model of P‐wave anisotropic tomography of the uppermost mantle beneath NE Asia obtained by inverting 88,303 high‐quality manually picked Pn arrival times. Our model reveals strong lateral heterogeneities in both isotropic velocity and azimuthal anisotropy. Distinct high Pn velocities are visible under the basins in NE China, and eastern and western Japan basins. Very high Pn velocities with trench‐normal fast Pn anisotropy are revealed near the Kurile‐Japan trench, representing the incoming Pacific plate. Prominent low Pn velocity anomalies are revealed under active intraplate volcanoes in NE China and arc volcanoes on the Japan Islands. Very low Pn velocities with trench‐parallel fast Pn anisotropy are observed along the volcanic front in Japan, reflecting compressed mantle flows. An NW‐SE oriented low‐velocity (low‐V) zone from the Wudalianchi volcano to the Changbaishan volcano meets the E‐W oriented low‐V zone around the Changbaishan volcano and the N‐S low‐V zone east of the Sanjiang basin, which converge to a broad N‐S low‐V zone. This zone passes through the central Japan basin to the junction of the Japan and Izu‐Bonin trenches, where it meets the nearly E‐W low‐V zone from the Changle volcano. These low‐V anomalies exhibit zone‐parallel fast Pn anisotropy and may indicate channels for material and energy exchanges among the volcanoes, driven by mantle flows in the big mantle wedge. These results provide new insights into interplate and intraplate volcanism and subduction dynamics in the study region.
Spatiotemporal Variability of Aragonite Saturation State in the Northern East China Sea
Authors: Choi Yujeong , Kim Tae‐Hoon , Kim Dongseon , Kang Dong‐Jin 
Published: January 2022

AbstractIn order to evaluate the spatiotemporal distribution of the carbonate system in the northern East China Sea (ECS), we first measured the seasonal dissolved inorganic carbon (DIC) and total alkalinity (TA), from which the aragonite saturation state (Ωarag) was calculated for the years 2015–2017. The DIC, TA, and Ωarag were 1,680.9–2,211.4 μmol kg−1, 2,145.1–2,312.8 μmol kg−1, and 1.2–6.0, respectively. The spatiotemporal variability of Ωarag in the northern ECS was mainly controlled by seasonal water mass, such as Yellow Sea Surface Water, Changjiang Dilute Water, and Yellow Sea Bottom Water (YSBW). The lowest Ωarag (∼1.4) in bottom layer was observed in high primary production areas caused by the extension of the Changjiang River plume with the higher Ωarag (up to 6) and was closely linked to the YSBW with low Ωarag expanded southward from Yellow Sea near bottom. Although this area was not a hypoxia zone unlike western shelf region (Chinese region) of the northern ECS, YSBW near bottom could enhance the suppression of bottom aragonite without hypoxia. In eastern region of northern ECS, higher production at surface, YSBW with lower Ωarag extension, and longer respiration product accumulations near bottom tend to lower Ωarag, as compared with western region where the summer hypoxia led to lower Ωarag. Therefore, this result indicates that the eastern region of the northern ECS is also susceptible to ocean acidification, along with the summer hypoxic zone of the western region.
Reduction in Anthropogenic Emissions Suppressed New Particle Formation and Growth: Insights From the COVID‐19 Lockdown
Authors: Kanawade V. P. , Sebastian M. , Dasari P. 
Published: January 2022

AbstractTo control the spread of the novel 2019 Coronavirus (COVID‐19), the Government of India enforced nationwide social and transportation restrictions (lockdown) in three phases from the evening of 24 March to 31 May 2020, which resulted in a significant reduction of primary emissions. Here, we performed the analyses of particle number size distribution measurements in the particle size range of 1.2–3 nm and 10–514 nm carried out from 15 April to 31 May 2020 (lockdown, LCD) and compared with measurements from the previous year during the same time period (15 April to 31 May 2019, business‐as‐usual, BAU) at University of Hyderabad in Hyderabad, India. The number concentrations of sub‐3 nm particles were comparable between LCD and BAU, but the number concentrations of particles greater than 10 nm diameter were lower by about 85% during LCD than BAU. It indicates that the reduction in primary anthropogenic emissions did not inhibit the formation of sub‐3 nm particles. But the frequency of occurrence of the new particle formation and growth (NPF&G) events was three‐fold lower during LCD than BAU. The ratio of formaldehyde to nitrogen dioxide indicated that India falls in a NOx‐limited regime, which reduces ambient ozone concentrations (lower condensable vapors via ozone oxidation of volatile organic compounds). Besides, the lower temperature (lower hydroxyl radical concentration) and lower wind speed during LCD may have contributed to the suppression of NPF&G events. Therefore, we emphasize the need to account for processes and interactions related to NPF&G in formulating particulate pollution mitigation policies in urban environments.
Multi‐Season Evaluation of CO2 Weather in OCO‐2 MIP Models
Authors: Zhang Li , Davis Kenneth J. , Schuh Andrew E. , Jacobson Andrew R. , Pal Sandip , Cui Yu Yan , Baker David , Crowell Sean , Chevallier Frederic , Remaud Marine , Liu Junjie , Weir Brad , Philip Sajeev , Johnson Matthew S. , Deng Feng , Basu Sourish 
Published: January 2022

AbstractThe ability of current global models to simulate the transport of CO2 by mid‐latitude, synoptic‐scale weather systems (i.e., CO2 weather) is important for inverse estimates of regional and global carbon budgets but remains unclear without comparisons to targeted measurements. Here, we evaluate ten models that participated in the Orbiting Carbon Observatory‐2 model intercomparison project (OCO‐2 MIP version 9) with intensive aircraft measurements collected from the Atmospheric Carbon Transport (ACT)‐America mission. We quantify model‐data differences in the spatial variability of CO2 mole fractions, mean winds, and boundary layer depths in 27 mid‐latitude cyclones spanning four seasons over the central and eastern United States. We find that the OCO‐2 MIP models are able to simulate observed CO2 frontal differences with varying degrees of success in summer and spring, and most underestimate frontal differences in winter and autumn. The models may underestimate the observed boundary layer‐to‐free troposphere CO2 differences in spring and autumn due to model errors in boundary layer height. Attribution of the causes of model biases in other seasons remains elusive. Transport errors, prior fluxes, and/or inversion algorithms appear to be the primary cause of these biases since model performance is not highly sensitive to the CO2 data used in the inversion. The metrics presented here provide new benchmarks regarding the ability of atmospheric inversion systems to reproduce the CO2 structure of mid‐latitude weather systems. Controlled experiments are needed to link these metrics more directly to the accuracy of regional or global flux estimates.
How Do Perceptions of Risk Communicator Attributes Affect Emergency Response? An Examination of a Water Contamination Emergency in Boston, USA
Authors: Hyman Amy , Arlikatti Sudha , Huang Shih‐Kai , Lindell Michael K. , Mumpower Jeryl , Prater Carla S. , Wu Hao‐Che 
Published: January 2022

AbstractA water main break that contaminated the Boston area's water distribution system prompted a four‐day “boil water” order. To understand risk communication during this incident, 600 randomly sampled residents were mailed questionnaires, yielding 110 valid responses. This article describes how perceptions of different social stakeholders influenced whether respondents complied with the Protective Action Recommendation—PAR (i.e., drank boiled water), took alternative protective actions (i.e., drank bottled water or/and self‐chlorinated water), or ignored the threat (i.e., continued to drink untreated tap water). Respondents perceived technical authorities (i.e., water utility, public health, and emergency management) to be higher on three social influence attributes (hazard expertize, trustworthiness, and protection responsibility) than public (i.e., news media, elected officials) and private (i.e., self/family, peers, and personal physicians) intermediate sources. Furthermore, respondents were most likely to comply with the PAR if they perceived authorities and public intermediates to be high on all three attributes and if they had larger households and lower income. Contrarily, they were more likely to take alternative actions if they were younger and had higher levels of income, risk perception, and emergency preparedness. These results underscore the need for technical authorities to develop credibility with their potential audiences before a crisis occurs.
Lasting Effects of Soil Compaction on Soil Water Regime Confirmed by Geoelectrical Monitoring
Authors: Romero‐Ruiz Alejandro , Linde Niklas , Baron Ludovic , Breitenstein Daniel , Keller Thomas , Or Dani 
Published: January 2022

AbstractDespite its importance for hydrological and ecological soil functioning, characterizing, and quantifying soil structure in the field remains a challenge. Traditional characterization of soil structure often relies on point measurements, more recently, we advanced the use of minimally invasive geophysical methods that operate at plot‐field scales and provide information under natural conditions. In this study, we expand the application using geoelectrical and time‐domain reflectometry (TDR) monitoring of soil water dynamics to infer impacts of compaction on soil structure and function. We developed a modeling scheme combining a new pedophysical model of soil electrical conductivity and a soil‐structure‐informed one‐dimensional water flow and heat‐transfer model. The model was used to interpret Direct Current (DC)‐resistivity and TDR monitoring data in compacted soils at the Soil Structure Observatory (SSO) located in the vicinity of Zürich, Switzerland. We find that (1) soil compaction leads to a persistent decrease in soil electrical resistivity and (2) that compacted soils are typically drier than non‐compacted soils during long drying events. The main decrease in electrical resistivity is attributed to decreasing macroporosity and increasing connectivity of soil aggregates due to compaction. Higher water losses in compacted soils are explained in terms of enhanced evaporation. Our work advances characterization of soil structure at the field scale with electrical methods by offering a physically based explanation of the impact of soil compaction on electrical properties and by interpreting DC‐resistivity data in terms of soil water dynamics.
Architecture engineering of nanostructured catalyst via layer-by-layer adornment of multiple nanocatalysts on silica nanorod arrays for hydrogenation of nitroarenes
Authors: Hong Kootak , Suh Jun Min , Lee Tae Hyung , Cho Sung Hwan , Ramakrishna Seeram , Varma Rajender S. , Jang Ho Won , Shokouhimehr Mohammadreza 
Published: January 2022

AbstractDirect consideration for both, the catalytically active species and the host materials provides highly efficient strategies for the architecture design of nanostructured catalysts. The conventional wet chemical methods have limitations in achieving such unique layer-by-layer design possessing one body framework with many catalyst parts. Herein, an innovative physical method is presented that allows the well-regulated architecture design for an array of functional nanocatalysts as exemplified by layer-by-layer adornment of Pd nanoparticles (NPs) on the highly arrayed silica nanorods. This spatially confined catalyst exhibits excellent efficiency for the hydrogenation of nitroarenes and widely deployed Suzuki cross-coupling reactions; their facile separation from the reaction mixtures is easily accomplished due to the monolithic structure. The generality of this method for the introduction of other metal source has also been demonstrated with Au NPs. This pioneering effort highlights the feasibility of physically controlled architecture design of nanostructured catalysts which may stimulate further studies in the general domain of the heterogeneous catalytic transformations.
Oxidative ornithine metabolism supports non-inflammatory C. difficile colonization
Authors: Pruss Kali M. , Enam Fatima , Battaglioli Eric , DeFeo Mary , Diaz Oscar R. , Higginbottom Steven K. , Fischer Curt R. , Hryckowian Andrew J. , Van Treuren William , Dodd Dylan , Kashyap Purna , Sonnenburg Justin L. 
Published: January 2022

AbstractThe enteric pathogen Clostridioides difficile (Cd) is responsible for a toxin-mediated infection that causes more than 200,000 recorded hospitalizations and 13,000 deaths in the United States every year1. However, Cd can colonize the gut in the absence of disease symptoms. Prevalence of asymptomatic colonization by toxigenic Cd in healthy populations is high; asymptomatic carriers are at increased risk of infection compared to noncolonized individuals and may be a reservoir for transmission of Cd infection2,3. Elucidating the molecular mechanisms by which Cd persists in the absence of disease is necessary for understanding pathogenesis and developing refined therapeutic strategies. Here, we show with gut microbiome metatranscriptomic analysis that mice recalcitrant to Cd infection and inflammation exhibit increased community-wide expression of arginine and ornithine metabolic pathways. To query Cd metabolism specifically, we leverage RNA sequencing in gnotobiotic mice infected with two wild-type strains (630 and R20291) and isogenic toxin-deficient mutants of these strains to differentiate inflammation-dependent versus -independent transcriptional states. A single operon encoding oxidative ornithine degradation is consistently upregulated across non-toxigenic Cd strains. Combining untargeted and targeted metabolomics with bacterial and host genetics, we demonstrate that both diet- and host-derived sources of ornithine provide a competitive advantage to Cd, suggesting a mechanism for Cd persistence within a non-inflammatory, healthy gut.
Circularity in animal production requires a change in the EAT-Lancet diet in Europe
Authors: van Selm Benjamin , Frehner Anita , de Boer Imke J. M. , van Hal Ollie , Hijbeek Renske , van Ittersum Martin K. , Talsma Elise F. , Lesschen Jan Peter , Hendriks Chantal M. J. , Herrero Mario , van Zanten Hannah H. E. 
Published: January 2022

AbstractIt is not known whether dietary guidelines proposing a limited intake of animal protein are compatible with the adoption of circular food systems. Using a resource-allocation model, we compared the effects of circularity on the supply of animal-source nutrients in Europe with the nutritional requirements of the EAT-Lancet reference diet. We found the two to be compatible in terms of total animal-source proteins but not specific animal-source foods; in particular, the EAT-Lancet guidelines recommend larger quantities of poultry meat over beef and pork, while a circular food system produces mainly milk, dairy-beef and pork. Compared with the EAT-Lancet reference diet, greenhouse gas emissions were reduced by up to 31% and arable land use reduced by up to 42%. Careful consideration of the feasible substitutability between animal-source foods is needed to define potential roles of animal products in circular human diets.
Responsibility of major emitters for country-level warming and extreme hot years
Authors: Beusch Lea , Nauels Alexander , Gudmundsson Lukas , Gütschow Johannes , Schleussner Carl-Friedrich , Seneviratne Sonia I. 
Published: January 2022

AbstractThe contributions of single greenhouse gas emitters to country-level climate change are generally not disentangled, despite their relevance for climate policy and litigation. Here, we quantify the contributions of the five largest emitters (China, US, EU-27, India, and Russia) to projected 2030 country-level warming and extreme hot years with respect to pre-industrial climate using an innovative suite of Earth System Model emulators. We find that under current pledges, their cumulated 1991–2030 emissions are expected to result in extreme hot years every second year by 2030 in twice as many countries (92%) as without their influence (46%). If all world nations shared the same fossil CO2 per capita emissions as projected for the US from 2016–2030, global warming in 2030 would be 0.4 °C higher than under actual current pledges, and 75% of all countries would exceed 2 °C of regional warming instead of 11%. Our results highlight the responsibility of individual emitters in driving regional climate change and provide additional angles for the climate policy discourse.
Cubic versus hexagonal – phase, size and morphology effects on the photoluminescence quantum yield of NaGdF4:Er3+/Yb3+ upconverting nanoparticles
Authors: Quintanilla Marta , Hemmer Eva , Marques-Hueso Jose , Rohani Shadi , Lucchini Giacomo , Wang Miao , Zamani Reza R. , Roddatis Vladimir , Speghini Adolfo , Richards Bryce S. , Vetrone Fiorenzo 
Published: January 2022

The photoluminescence quantum yield (PLQY) of NaGdF4:Er3+/Yb3+ upconverting nanoparticles (UCNPs) as a function of size and shape is studied. Sub-20 nm α-phase UCNPs showed a higher PLQY compared to similar size β-phase UCNPs.
A few upstream bifurcations drive the spatial distribution of red blood cells in model microfluidic networks
Authors: Merlo Adlan , Berg Maxime , Duru Paul , Risso Frédéric , Davit Yohan , Lorthois Sylvie 
Published: January 2022

We show how Red Blood Cell (RBC) transverse migration downstream the first bifurcation of the network has an outsized impact on the RBC distribution at large scale, depending on the network architecture, as illustrated here for a square network.
The resolved jet of 3C 273 at 150 MHz
Authors: Harwood J. J. , Mooney S. , Morabito L. K. , Quinn J. , Sweijen F. , Groeneveld C. , Bonnassieux E. , Kappes A. , Moldon J. 
Published: January 2022

Context.Since its discovery in 1963, 3C 273 has become one of the most widely studied quasars with investigations spanning the electromagnetic spectrum. While much has therefore been discovered about this historically notable source, its low-frequency emission is far less well understood. Observations in the megahertz (MHz) regime have traditionally lacked the resolution required to explore small-scale structures, such as knots and diffuse jet emission, that are crucial to understanding the processes that result in the observed emission. Advances in the processing of LOFAR international baseline data have now removed this limitation, providing the opportunity to explore this key area for the first time.Aims.In this paper we use the first sub-arcsecond images of 3C 273 at MHz frequencies to investigate the morphology of the compact jet structures and the processes that result in the observed spectrum. We determine the jet’s kinetic power, place constraints on the bulk speed and inclination angle of the jets, and look for evidence of the elusive counterjet at 150 MHz.Methods.Using the full complement of the LOFAR international stations (German, Poland, France, UK, Sweden), we produce 0.31 × 0.21 arcsec images of 3C 273 at 150 MHz. Using ancillary data at gigahertz frequencies, we fit free-free absorption (FFA) and synchrotron self-absorption (SSA) models to each region in order to determine their validity in explaining the observed spectra.Results.The images presented display for the first time that robust high-fidelity imaging of low-declination complex sources is now possible with the LOFAR international baselines. We show that the main small-scale structures of 3C 273 match those seen at higher frequencies, with a tenuous detection of an extension to the outer lobe. We find that FFA and SSA models are able to describe the spectrum of the knots and, while differentiating between model types requires further observations, we conclude that absorption is present in the observed emission. We determine the kinetic power of the jet to be in the range of 3.5 × 1043–1.5 × 1044erg s−1, which agrees with estimates made using higher frequency observations. We derive lower limits for the bulk speed and Lorentz factor ofβ≳ 0.55 and Γ ≥ 1.2, respectively. The counterjet remains undetected at 150 MHz, placing a limit on the peak brightness ofScj_150< 40 mJy beam−1.
The width of Herschel filaments varies with distance
Authors: Panopoulou G. V. , Clark S. E. , Hacar A. , Heitsch F. , Kainulainen J. , Ntormousi E. , Seifried D. , Smith R. J. 
Published: January 2022

Context. Filamentary structures in nearby molecular clouds have been found to exhibit a characteristic width of 0.1 pc, as observed in dust emission. Understanding the origin of this universal width has become a topic of central importance in the study of molecular cloud structure and the early stages of star formation.
Aims. We investigate how the recovered widths of filaments depend on the distance from the observer by using previously published results from the Herschel Gould Belt Survey.
Methods. We obtained updated estimates on the distances to nearby molecular clouds observed with Herschel by using recent results based on 3D dust extinction mapping and Gaia. We examined the widths of filaments from individual clouds separately, as opposed to treating them as a single population. We used these per-cloud filament widths to search for signs of variation amongst the clouds of the previously published study.
Results. We find a significant dependence of the mean per-cloud filament width with distance. The distribution of mean filament widths for nearby clouds is incompatible with that of farther away clouds. The mean per-cloud widths scale with distance approximately as 4−5 times the beam size. We examine the effects of resolution by performing a convergence study of a filament profile in the Herschel image of the Taurus Molecular Cloud. We find that resolution can severely affect the shapes of radial profiles over the observed range of distances.
Conclusions. We conclude that the data are inconsistent with 0.1 pc being the universal characteristic width of filaments.
Total reflection of a flare-driven quasi-periodic extreme ultraviolet wave train at a coronal hole boundary
Authors: Zhou Xinping , Shen Yuandeng , Tang Zehao , Zhou Chengrui , Duan Yadan , Tan Song 
Published: January 2022

Context. A flare-driven quasi-periodic extreme ultraviolet wave train totally reflected at a coronal hole boundary was well imaged on both temporal and spatial scales by AIA/SDO.
Aims. We aim to investigate the driving mechanisms of the quasi-periodic wave train and demonstrate the total reflection effect at the coronal hole boundary.
Methods. The speeds of the incident and reflected wave trains are studied. The periodic correlation of the wave trains with the related flare is probed. We compare the measured incidence angle and the estimated critical angle.
Results. We find that the periods of the incident and reflected wave trains are both about 100 s. The excitation of the quasi-periodic wave train was possibly due to the intermittent energy release in the associated flare since its period is similar to that of the quasi-periodic pulsations in the associated flare. Our observational results show that the reflection of the wave train at the boundary of the coronal hole was a total reflection because the measured incidence and critical angles satisfy the theory of total reflection: the incidence angle is smaller than the critical angle.