bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of MODIS and Himawari‐8 Low Clouds Retrievals Over the Southern Ocean With In Situ Measurements From the SOCRATES Campaign
Authors: Kang Litai , Marchand Roger , Smith William 
Published: January 2021

AbstractAircraft observations collected during the Southern Ocean Cloud Radiation Aerosol Transport Experimental Study in January‐February of 2018 are used to evaluate cloud properties from three satellite‐imager datasets: (1) the Moderate Resolution Imaging Spectroradiometer level 2 (collection 6.1) cloud product, (2) the CERES‐MODIS Edition 4 cloud product, and (3) the NASA SatCORPS Himawari‐8 cloud product. Overall the satellite retrievals compare well with the in situ observations, with little bias and modest to good correlation coefficients when considering all aircraft profiles for which there are coincident MODIS observations. The Himawari‐8 product does, however, show a statistically significant mean bias of about 1.2 μm for effective radius (re) and 2.6 for optical depth (τ) when applied to a larger set of profiles with coincident Himawari‐8 observations. The low overall mean‐bias in the re retrievals is due in part to compensating errors between cases that are non‐ or lightly precipitating, with cases that have heavier precipitation. re is slightly biased high (by about 0.5–1.0 μm) for non‐ and lightly precipitating cases and biased low by about 3–4 μm for heavily precipitating cases when precipitation exits near cloud top. The bias in non‐ and lightly precipitating conditions is due to (at least in part) having assumed a drop size distribution in the retrieval that is too broad. These biases in the re ultimately propagate into the retrieved liquid water path and number concentration.
A Thermo‐Compositional Model of the Cratonic Lithosphere of South America
Authors: Finger N.‐P. , Kaban M. K. , Tesauro M. , Haeger C. , Mooney W. D. , Thomas M. 
Published: January 2021

AbstractNew seismic data on the crust and upper mantle of South America have recently become available and describe its deep structure with unprecedented resolution. Here, seismic data are combined with gravity data and mineral physics constraints to develop self‐consistent models of the temperature, composition, and density of the South American lithospheric and sub‐lithospheric upper mantle. A new model of the crustal structure was developed, including sediment and average crustal density and depth to the Moho. This crustal model was used to correct the gravity field and obtain the residual topography. Then, an initial temperature model, derived from seismic tomography and mineral physics, was improved through an iterative process based on the joint inversion of gravity and residual topography. The results reveal deep cratonic roots present under wide parts of the Amazon, São Francisco, and Paranapanema Cratons, but not under the Rio de la Plata and Parnaíba Cratons. These cratons probably never developed lithospheric roots or were rejuvenated during subsequent tectonic events. We hypothesize that the root of the northwestern Amazon craton was removed by upwelling of hot mantle material under the Guyana highlands. Temperature and density anomalies evident beneath the São Francisco Craton appear to be connected with those of the Paranapanema Craton, which could indicate a westward shift of its root. Depletion south of the Paranapanema Craton probably denotes remnants of a previously larger craton that was rejuvenated by the upwelling of hot mantle material leading to emplacement of the Paraná Flood Basalts.
Source‐to‐Sink Terrestrial Analogs for the Paleoenvironment of Gale Crater, Mars
Authors: Thorpe Michael T. , Hurowitz Joel A. , Siebach Kirsten L. 
Published: January 2021

AbstractIn the Late Noachian to Early Hesperian period, rivers transported detritus from igneous source terrains to a downstream lake within Gale crater, creating a stratified stack of fluviolacustrine rocks that is currently exposed along the slopes of Mount Sharp. Controversy exists regarding the paleoclimate that supported overland flow of liquid water at Gale crater, in large part because little is known about how chemical and mineralogical paleoclimate indicators from mafic‐rock dominated source‐to‐sink systems are translated into the rock record. Here, we compile data from basaltic terrains with varying climates on Earth in order to provide a reference frame for the conditions that may have prevailed during the formation of the sedimentary strata in Gale crater, particularly focusing on the Sheepbed and Pahrump Hills members. We calculate the chemical index of alteration for weathering profiles and fluvial sediments to better constrain the relationship between climate and chemical weathering in mafic terrains, a method that best estimates the cooler limit of climate conditions averaged over time. We also compare X‐ray diffraction patterns and mineral abundances from fluvial sediments in varying terrestrial climates and martian mudstones to better understand the influence of climate on secondary mineral assemblages in basaltic terrains. We show that the geochemistry and mineralogy of most of the fine‐grained sedimentary rocks in Gale crater display first‐order similarities with sediments generated in climates that resemble those of present‐day Iceland, while other parts of the stratigraphy indicate even colder baseline climate conditions. None of the lithologies examined at Gale crater resemble fluvial sediments or weathering profiles from warm (temperate to tropical) terrestrial climates.
Variations in Mid‐ to Late Holocene Nitrogen Supply to Northern Great Barrier Reef Halimeda Macroalgal Bioherms
Authors: McNeil Mardi , Nothdurft Luke , Erler Dirk , Hua Quan , Webster Jody M. 
Published: January 2021

AbstractThe northern Great Barrier Reef (GBR) Halimeda bioherms have accumulated on the outer continental shelf from calcium carbonate algal sediments over the past ∼10,000 years and cover >6,000 km2 of shelf area. As such, Halimeda bioherms play a key role in the shallow marine carbon cycle over millennial timescales. The main source of nitrogen (N) to these bioherms is thought to be westward transport of upwelled NO3‐‐rich water from the Coral Sea. However, the primary N source has not been traced geochemically, and we have no understanding of any temporal variation. Here, we reconstruct patterns of N supply to Halimeda bioherms in the GBR since the mid‐Holocene using the 15N/14N ratio of skeletal‐bound organic N (δ15N‐skeletal organic material [SOM]) in modern and fossil Halimeda sediment cores. Average Halimeda skeletal δ15N‐SOM was 6.28 ± 0.26‰, consistent with δ15N‐NO3‐ from western tropical South Pacific (WTSP) thermocline waters. Thus, geochemically validating shelf‐break upwelling of an oceanic N source that regulates bioherm spatial distribution. Halimeda δ15N‐SOM decreased by 1‰–2‰ from 5,000 to 2,000 cal. yr BP, reaching a minima of 5.5‰ that persisted for almost 1,000 years. The Halimeda δ15N‐SOM variation reflects mid‐ to late Holocene changes in regional climate and intensified El Niño activity that likely facilitated elevated N2 fixation in the WTSP, thereby lowering thermocline δ15N‐NO3‐. Thus, Halimeda skeletal material provides a valuable high‐resolution geochemical archive of past oceanographic and climatic processes over centennial to millennial timescales, complementing existing paleoclimate proxy records.
Holocene Moisture Variability and Its Lagged Response to Summer Insolation Revealed by Eolian Deposits in the Lake Qinghai Basin, NE Tibetan Plateau
Authors: Ding Zhiyong , Lu Ruijie , Wang Lindong 
Published: January 2021

AbstractThe evolution of the East Asian Summer Monsoon (EASM) and its mechanism since the Holocene remains controversial. Here, we investigate four eolian sediment sequences in the Lake Qinghai Basin (LQB), Northeastern Tibetan Plateau (NETP), in the marginal zone of the modern EASM. The results indicate that paleoclimatological interpretation of the color parameters and CaCO3 in eolian sand‐paleosol sequence from LQB region are different from the loess‐paleosol sequence in Loess Plateau, and a comprehensive analysis that combines lithostratigraphic and other proxy data is required. Changes in the EASM dominated climate change in the NETP, with a gradual increase in moisture from the beginning of the early‐Holocene, however the environment was relatively cold and dry with strong regional eolian sand activity. During 8.5–3.3 ka, the intensity of the EASM and effective moisture levels in the LQB reached a peak. Eolian activity was weak and dunes were effectively fixed in place, while pedogenesis processes were enhanced and paleosols developed widely across the region. Moisture levels decreased after 3.3 ka and the dunes were reactivated, eolian activity was enhanced, and there was extensive accumulation of eolian sand and sandy loess. These records show that moisture variability has been controlled by the EASM system in east Asia since at least the Holocene, and has generally responded to changes in northern hemisphere summer insolation with a lag of 3–5 ka, through mechanisms that are modulated by high‐latitude ice‐volume forcing and large‐scale ocean‐atmospheric circulation patterns.
Characterizing the Source of the Eastern Galicia Magnetic Anomaly (NW Spain): The Role of Extension in the Origin of Magnetization at the Central Iberian Arc
Authors: Ayarza Puy , Villalaín Juan José , Martínez Catalán José Ramón , Álvarez Lobato Fernando , Durán Oreja Manuela , Calvín Pablo , Recio Clemente , Suárez Barrios Mercedes , Gómez Martín Elena 
Published: January 2021

AbstractThe Eastern Galicia Magnetic Anomaly is the best studied anomaly of the Central Iberian Arc. This is due to its location, on the Lugo‐Sanabria gneiss dome, and to the fact that its source rocks crop out in the Xistral Tectonic Window. Multiple studies of this anomaly have been carried out, but still, new results keep on shedding light on its understanding. This paper presents the first results on rock magnetic analyses, natural remanent magnetization, anisotropy of the magnetic susceptibility, X‐ray diffraction, and stable isotopes geochemistry carried out on the source rocks of this anomaly. Results suggest that magnetization responds to the increase in oxygen fugacity underwent by rocks affected by late Variscan (330‐300 Ma) extensional tectonics. Extensional detachments were the pathways that allowed the entrance of fluids that led to syntectonic crystallization of magnetite and hematite in metasediments and inhomogeneous S‐Type granitoids derived from their partial melting. Accordingly, magnetization is not linked to lithologies, but to extensional structures developed in the late Carboniferous/earliest Permian, during the Kiaman reverse superchron. Systematic reverse magnetic remanence exhibited by hematite‐bearing samples confirms the age of the magnetization and adds complexity to the interpretation of the anomaly. Understanding the EGMA contributes to the interpretation of other anomalies existing in the CIA, also located on thermal domes. The observed extension‐related magnetization probably affected most of the NW Iberian Massif, thus hindering the study of previous tectonics by paleomagnetic techniques. This work aims to provide new hints to interpret magnetic anomalies located in extensional tectonic contexts worldwide.
East Tacheng (Qoqek) Fault Zone: Late Quaternary Tectonics and Slip Rate of a Left‐Lateral Strike‐Slip Fault Zone North of the Tian Shan
Authors: Yu Jingxing , Walker R. T. , Rhodes E. J. , Zhang Peizhen , Li Chaopeng , Wang Siyu , Wang Yizhou , Liu Fangbin , Hao Yuqi 
Published: January 2021

AbstractAlthough the Tacheng Basin may play an important role in accommodating crustal shortening north of the Tian Shan and west of the Junggar Basin based on observations of several conspicuous surface ruptures in satellite imagery, little is known about its late Quaternary tectonic activity. We analyze the tectonic geomorphology of the East Tacheng fault zone, including the subparallel NE‐SW trending East Tacheng and Wuerkashier faults, using field observations, interpretations of satellite imagery, and construction of decimeter‐scale digital elevation models from unmanned aerial vehicle surveys. Geomorphological features such as displaced stream channels and terrace risers, negligible vertical offset, opposite facing directions of a single fault scarp, and linear fault traces suggest that the East Tacheng fault is a nearly pure left‐lateral subvertical strike‐slip fault. The late Quaternary horizontal slip rate is estimated to be 0.4–2.0 mm/year, likely ∼0.7 mm/year. Paleoearthquake studies in trenches reveal that the most recent earthquake occurred between 3.1 and 0.5 ka. The Wuerkashier fault, which shows pristine surface ruptures along a total length of ∼67 km, is also a nearly pure left‐lateral strike‐slip fault. The most recent earthquake along this fault is dated to be 7.9–0.5 ka. Combining GPS velocity and active fault kinematics in the northern Tian Shan and western Junggar, we suggest that the western Junggar is controlled by regional N‐S crustal shortening related to the India‐Eurasia collision, and the reactivated Paleozoic fault zones in the western Junggar play a key role in transferring deformation northeastward into the Altai and Mongolia.
Sequential Data Assimilation for Streamflow Forecasting: Assessing the Sensitivity to Uncertainties and Updated Variables of a Conceptual Hydrological Model at Basin Scale
Authors: Piazzi G. , Thirel G. , Perrin C. , Delaigue O. 
Published: January 2021

AbstractSkillful streamflow forecasts provide key support to several water‐related applications. Because of the critical impact of initial conditions (ICs) on forecast accuracy, ever‐growing interest is focused on improving their estimates via data assimilation (DA). This study aims to assess the sensitivity of the DA‐based estimation of forecast ICs to several sources of uncertainty and the update of different model states and parameters of a lumped conceptual rainfall–runoff model over 232 watersheds in France. The performance of two sequential ensemble‐based techniques, namely, the ensemble Kalman filter (EnKF) and the particle filter (PF), is compared in terms of efficiency and temporal persistence (up to 10 days) of the updating effect through the assimilation of observed discharges. Several experiments specifically address the impact of the meteorological, state, and parameter uncertainties. Results show that an accurate estimate of the initial level of the routing store of the conceptual model ensures the most benefit to the DA‐based estimation of forecast ICs. While EnKF‐based forecasts outperform PF‐based ones when accounting for meteorological uncertainty, the more comprehensive representation of the state uncertainty makes it possible to greatly improve the accuracy of PF‐based predictions, with a longer‐lasting updating effect. Conversely, forecasting skill is undermined when accounting for parameter uncertainty, owing to the change in hydrological responsiveness. This study extensively addresses several sensitivity analyses in order to provide useful recommendations for designing DA‐based streamflow forecasting systems and for diagnosing possible deficiencies in existing systems.
Estimating and reporting treatment effects in clinical trials for weight management: using estimands to interpret effects of intercurrent events and missing data
Authors: Wharton Sean , Astrup Arne , Endahl Lars , Lean Michael E. J. , Satylganova Altynai , Skovgaard Dorthe , Wadden Thomas A. , Wilding John P. H. 
Published: January 2021

AbstractIn the approval process for new weight management therapies, regulators typically require estimates of effect size. Usually, as with other drug evaluations, the placebo-adjusted treatment effect (i.e., the difference between weight losses with pharmacotherapy and placebo, when given as an adjunct to lifestyle intervention) is provided from data in randomized clinical trials (RCTs). At first glance, this may seem appropriate and straightforward. However, weight loss is not a simple direct drug effect, but is also mediated by other factors such as changes in diet and physical activity. Interpreting observed differences between treatment arms in weight management RCTs can be challenging; intercurrent events that occur after treatment initiation may affect the interpretation of results at the end of treatment. Utilizing estimands helps to address these uncertainties and improve transparency in clinical trial reporting by better matching the treatment-effect estimates to the scientific and/or clinical questions of interest. Estimands aim to provide an indication of trial outcomes that might be expected in the same patients under different conditions. This article reviews how intercurrent events during weight management trials can influence placebo-adjusted treatment effects, depending on how they are accounted for and how missing data are handled. The most appropriate method for statistical analysis is also discussed, including assessment of the last observation carried forward approach, and more recent methods, such as multiple imputation and mixed models for repeated measures. The use of each of these approaches, and that of estimands, is discussed in the context of the SCALE phase 3a and 3b RCTs evaluating the effect of liraglutide 3.0 mg for the treatment of obesity.
Self-powered ammonia synthesis under ambient conditions via N2 discharge driven by Tesla turbine triboelectric nanogenerators
Authors: Han Kai , Luo Jianjun , Chen Jian , Chen Baodong , Xu Liang , Feng Yawei , Tang Wei , Wang Zhong Lin 
Published: January 2021

AbstractAmmonia synthesis using low-power consumption and eco-friendly methods has attracted increasing attention. Here, based on the Tesla turbine triboelectric nanogenerator (TENG), we designed a simple and effective self-powered ammonia synthesis system by N2 discharge. Under the driving of the simulated waste gas, the Tesla turbine TENG showed high rotation speed and high output. In addition, the performance of two Tesla turbine TENGs with different gas path connections was systematically investigated and discussed. A controllable series-parallel connection with the control of gas supply time was also proposed. Taking advantage of the intrinsic high voltage, corona discharge in a N2 atmosphere was simply realized by a Tesla turbine TENG. With the flow of N2, the generated high-energy plasma can immediately react with water molecules to directly produce ammonia. The self-powered system achieved a yield of 2.14 μg h−1 (0.126 μmol h−1) under ambient conditions, showing great potential for large-scale synthesis.
Acoustic radiation-free surface phononic crystal resonator for in-liquid low-noise gravimetric detection
Authors: Gao Feng , Bermak Amine , Benchabane Sarah , Robert Laurent , Khelif Abdelkrim 
Published: January 2021

AbstractAcoustic wave resonators are promising candidates for gravimetric biosensing. However, they generally suffer from strong acoustic radiation in liquid, which limits their quality factor and increases their frequency noise. This article presents an acoustic radiation-free gravimetric biosensor based on a locally resonant surface phononic crystal (SPC) consisting of periodic high aspect ratio electrodes to address the above issue. The acoustic wave generated in the SPC is slower than the sound wave in water, hence it prevents acoustic propagation in the fluid and results in energy confinement near the electrode surface. This energy confinement results in a significant quality factor improvement and reduces frequency noise. The proposed SPC resonator is numerically studied by finite element analysis and experimentally implemented by an electroplating-based fabrication process. Experimental results show that the SPC resonator exhibits an in-liquid quality factor 15 times higher than a conventional Rayleigh wave resonator at a similar operating frequency. The proposed radiation suppression method using SPC can also be applied in other types of acoustic wave resonators. Thus, this method can serve as a general technique for boosting the in-liquid quality factor and sensing performance of many acoustic biosensors.
Novel therapeutic evaluation biomarkers of lipid metabolism targets in uncomplicated pulmonary tuberculosis patients
Authors: Chen Jia-Xi , Han Yu-Shuai , Zhang Shan-Qiang , Li Zhi-Bin , Chen Jing , Yi Wen-Jing , Huang Huai , Jiang Ting-Ting , Li Ji-Cheng 
Published: January 2021

AbstractCurrently, the management of pulmonary tuberculosis (TB) lacks potent medications and accurate efficacy evaluation biomarkers. In view of the fact that the host lipids are the important energy source of Mycobacterium tuberculosis (Mtb), UPLC-MS/MS based on lipid metabolism was used to monitor the plasma lipid spectrum of TB patients from the initial diagnosis to cured. The analysis showed that TB patients presented aberrant metabolism of phospholipids, glycerides, and sphingolipids. Upon the treatment, the abnormal expression of Cer (d18:1/24:0), CerP (d18:1/20:3), LPE (0:0/22:0), LPA (0:0/16:0), and LPA (0:0/18:0) in TB patients were gradually normalized, indicating that the intervention of lipid metabolism could block energy metabolism and inhibit the cell wall synthesis of Mtb. Furthermore, the increase in ceramide (Cer) levels could promote autophagosome–lysosome fusion. LPA (0:0/16:0) and LPA (0:0/18:0) had a great potential in the early diagnosis (both sensitivity and specificity were 100%) and efficacy evaluation (both sensitivity and specificity were 100%) of TB, indicating that the above lipid metabolites could be used as potential biomarkers for TB.
DNA methylome signatures of prenatal exposure to synthetic glucocorticoids in hippocampus and peripheral whole blood of female guinea pigs in early life
Authors: Sasaki Aya , Eng Margaret E. , Lee Abigail H. , Kostaki Alisa , Matthews Stephen G. 
Published: January 2021

AbstractSynthetic glucocorticoids (sGC) are administered to women at risk of preterm delivery, approximately 10% of all pregnancies. In animal models, offspring exposed to elevated glucocorticoids, either by administration of sGC or endogenous glucocorticoids as a result of maternal stress, show increased risk of developing behavioral, endocrine, and metabolic dysregulation. DNA methylation may play a critical role in long-lasting programming of gene regulation underlying these phenotypes. However, peripheral tissues such as blood are often the only accessible source of DNA for epigenetic analyses in humans. Here, we examined the hypothesis that prenatal sGC administration alters DNA methylation signatures in guinea pig offspring hippocampus and whole blood. We compared these signatures across the two tissue types to assess epigenetic biomarkers of common molecular pathways affected by sGC exposure. Guinea pigs were treated with sGC or saline in late gestation. Genome-wide modifications of DNA methylation were analyzed at single nucleotide resolution using reduced representation bisulfite sequencing in juvenile female offspring. Results indicate that there are tissue-specific as well as common methylation signatures of prenatal sGC exposure. Over 90% of the common methylation signatures associated with sGC exposure showed the same directionality of change in methylation. Among differentially methylated genes, 134 were modified in both hippocampus and blood, of which 61 showed methylation changes at identical CpG sites. Gene pathway analyses indicated that prenatal sGC exposure alters the methylation status of gene clusters involved in brain development. These data indicate concordance across tissues of epigenetic programming in response to alterations in glucocorticoid signaling.