bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pre‐Oxfordian (>163 Ma) Ophiolite Obduction in Central Tibet
Authors: Ma Anlin , Hu Xiumian , Kapp Paul , BouDagher‐Fadel Marcelle , Lai Wen 
Published: April 2020

AbstractThe timing of Bangong‐Nujiang suture ophiolite obduction between the Lhasa and Qiangtang terranes in central Tibet is important for understanding the closure history of the Meso‐Tethys but remains poorly constrained. We investigated subaerial to shallow marine strata of the Dongqiao Formation that sit unconformably on Bangong‐Nujiang suture ophiolites that crystallized in a supra‐subduction zone setting at 189–181 Ma. Based on foraminiferal and coral studies, the depositional age of the Dongqiao Formation is constrained to be Oxfordian and Kimmeridgian (Late Jurassic). Provenance analyses including detrital modes, geochemistry of detrital chromian spinels, and U‐Pb age populations of detrital zircons suggest the Dongqiao Formation was sourced from uplifted Bangong‐Nujiang suture ophiolites and sedimentary and metamorphic rocks of Lhasa terrane affinity to the south. We conclude that Bangong‐Nujiang suture ophiolites were obducted soon after crystallization (prior to Oxfordian time; >163 Ma) onto the Lhasa terrane or a microcontinent of Lhasa terrane affinity.
Aerosol Effects on Lightning Characteristics: A Comparison of Polluted and Clean Regimes
Authors: Liu Y. , Guha A. , Said R. , Williams E. , Lapierre J. , Stock M. , Heckman S. 
Published: April 2020

AbstractOceanic lightning can be a sensitive indicator of aerosol effects on lightning characteristics as thermodynamic contrast is indistinct over adjacent oceanic regions. The study presents discernable aerosol impacts on lightning characteristics by analyzing 2 years (2017–2018) of intracloud (IC) and cloud‐to‐ground (CG) lightning data from Earth Networks Total Lightning Network over two key regions in southern South China Sea. Mean stroke density, IC/CG ratio, +IC fraction, and +CG fraction in polluted conditions are respectively 3.7, 2, 1.2, and 5.8‐fold larger than unpolluted counterparts. Total stroke contrast is further confirmed with the GLD360 network. Thermodynamic parameters conversely support slightly stronger convection over clean ocean. Clear evidence shows cloud droplet size diminishes with added aerosol. Aerosol invigorates more frequent and robust mixed‐phase development, endowing maritime convection with continental characteristics. Modifications in the charge reversal temperature and lower and upper positive charge regions are speculated on as means for stimulating more positive ICs and CGs.
Magnetic Properties of Sedimentary Smythite (Fe9S11)
Authors: Horng Chorng‐Shern , Roberts Andrew P. , Chen Yen‐Hua , Shea Kai‐Shuan , Chen Kuo‐Hang , Lin Chun‐Hung , Zhao Xiang , Chang Chung‐Kai 
Published: April 2020

AbstractSmythite (Fe9S11) is an occasionally reported magnetic iron sulfide mineral that occurs in varied geological settings and co‐occurs commonly with other magnetic iron sulfide minerals. Determining the magnetic properties of smythite is important for understanding its geological distribution and paleomagnetic and environmental magnetic significance. We report sedimentary smythite occurrences from three locations in Taiwan (one terrestrial and two marine), which suggest that smythite forms in methanic diagenetic environments into which sulfide has been reintroduced. We report the magnetic properties of our purest smythite sample, which also contains greigite, and compare them with those of other magnetic iron sulfide minerals. The magnetization of smythite is controlled by multiaxial anisotropy, with magnetic easy axes that lie within the crystallographic basal plane. Smythite is magnetically stable with no low‐temperature magnetic transition. Hysteresis and coercivity properties of stable single domain smythite are similar to those of greigite at and below room temperature. The magnetic properties of smythite at elevated temperatures are dominated by thermal alteration, which precludes Curie temperature determination. In contrast to greigite and like pyrrhotite polytypes, smythite crystals occur as hexagonal plates. This morphological contrast facilitates discrimination of smythite from greigite in electron microscope observations, but it does not assist discrimination from pyrrhotite. Similar magnetic and morphological properties between smythite and other magnetic iron sulfides means that diagnostic mineralogical analyses (e.g., X‐ray diffraction) are needed to identify these minerals.
Critical Percolation Threshold Restricts Late‐Summer Arctic Sea Ice Melt Pond Coverage
Authors: Popović Predrag , Silber Mary C. , Abbot Dorian S. 
Published: April 2020

AbstractDuring the summer, vast regions of Arctic sea ice are covered by meltwater ponds that significantly lower the ice reflectivity and accelerate melting. Ponds develop over the melt season through an initial rapid growth stage followed by drainage through macroscopic holes. Recent analysis of melt pond photographs indicates that late‐summer ponds exist near the critical percolation threshold, a special pond coverage fraction below which the ponds are largely disconnected and above which they are highly connected. Here, we show that the percolation threshold, a statistical property of ice topography, constrains pond evolution due to pond drainage through macroscopic holes. We show that it sets the approximate upper limit and scales pond coverage throughout its evolution after the beginning of drainage. Furthermore, we show that the rescaled pond coverage during drainage is a universal function of a single non‐dimensional parameter, η, roughly interpreted as the number of drainage holes per characteristic area of the surface. This universal curve allows us to formulate an equation for pond coverage time‐evolution during and after pond drainage that captures the dependence on environmental parameters and is supported by observations on undeformed first‐year ice. This equation reveals that pond coverage is highly sensitive to environmental parameters, suggesting that modeling uncertainties could be reduced by more directly parameterizing the ponds' natural parameter, η. Our work uncovers previously unrecognized constraints on melt pond physics and places ponds within a broader context of phase transitions and critical phenomena. Therefore, it holds promise for improving ice‐albedo parameterizations in large‐scale models.
Disentangling the Microphysical Effects of Fire Particles on Convective Clouds Through A Case Study
Authors: Takeishi Azusa , Storelvmo Trude , Fierce Laura 
Published: April 2020

AbstractAerosol emissions from forest fires may impact cloud droplet activation through an increase in particle number concentrations (“the number effect”) and also through a decrease in the hygroscopicity κ of the entire aerosol population (“the hygroscopicity effect”) when fully internal mixing is assumed in models. This study investigated these effects of fire particles on the properties of simulated deep convective clouds (DCCs), using cloud‐resolving simulations with the Weather Research and Forecasting model coupled with Chemistry for a case study in a partly idealized setting. We found that the magnitude of the hygroscopicity effect was in some cases strong enough to entirely offset the number/size effect, in terms of its influence on modeled droplet and ice crystal concentrations. More specifically, in the case studied here, the droplet number concentration was reduced by about 37% or more due solely to the hygroscopicity effect. In the atmosphere, by contrast, fire particles likely have a much weaker impact on the hygroscopicity of the pre‐existing background aerosol, as such a strong impact would occur only if the fire particles mixed immediately and uniformly with the background. We also show that the differences in the number of activated droplets eventually led to differences in the optical thickness of the clouds aloft, though this finding is limited to only a few hours of the initial development stage of the DCCs. These results suggest that accurately and rigorously representing aerosol mixing and κ in models is an important step toward accurately simulating aerosol‐cloud interactions under the influence of fires.
Albedo of Black Carbon‐Contaminated Snow Across Northwestern China and the Validation With Model Simulation
Authors: Shi Tenglong , Pu Wei , Zhou Yue , Cui Jiecan , Zhang Daizhou , Wang Xin 
Published: April 2020

AbstractLight‐absorbing particles in snow can significantly reduce the snow albedo. Quantification of the influence of black carbon (BC), one of the most important light‐absorbing particles, on snow albedo is essential for understanding the budgets of solar radiation on snow‐covered areas. We measured BC concentration in snow at 28 sites and snow albedo at 18 sites in a vast region across northwestern China in January 2018. The BC concentration was in a wide range of 40–1,850 ng g−1. The presence of the BC reduced the snow albedo by 0.01–0.20 at the visible wavelength band (400–750 nm). The reduction differed from sites to sites with large values close to industrial areas that are characterized by high pollutants emission. Albedos simulated with a Snow, Ice, and Aerosol Radiation model based on the measured BC agreed well with the measured albedos, with the deviation within ±0.03 and the average underestimation of <0.002. It worth noting that the retrieved optical effective snow grain radius was the key factor in snow albedo calculation. The BC‐induced radiative forcing was estimated to be 0.2–6.9 W m−2, indicating strong acceleration of snowmelt due to BC in northwestern China. All obtained data are extremely valuable for climate model validation associated with the albedo of BC‐contaminated snow cover.
Development of Future Heatwaves for Different Hazard Thresholds
Authors: Vogel Martha M. , Zscheischler Jakob , Fischer Erich M. , Seneviratne S. I. 
Published: April 2020

AbstractIn 2018 and 2019, heatwaves set all‐time temperature records around the world and caused adverse effects on human health, agriculture, natural ecosystems, and infrastructure. Often, severe impacts relate to the joint spatial and temporal extent of the heatwaves, but most research so far focuses either on spatial or temporal attributes of heatwaves. Furthermore, sensitivity of heatwaves characteristics to the choice of the heatwave thresholds in a warming climate are rarely discussed. Here, we analyze the largest spatiotemporal moderate heatwaves—that is, three‐dimensional (space‐time) clusters of hot days—in simulations of global climate models. We use three different hazard thresholds to define a hot day: fixed thresholds (time‐invariant climatological thresholds), seasonally moving thresholds based on changes in the summer means, and fully moving thresholds (hot days defined relative to the future climatology). We find a substantial increase of spatiotemporally contiguous moderate heatwaves with global warming using fixed thresholds, whereas changes for the other two hazard thresholds are much less pronounced. In particular, no or very little changes in the overall magnitude, spatial extent, and duration are detected when heatwaves are defined relative to the future climatology using a temporally fully moving threshold. This suggests a dominant contribution of thermodynamic compared to dynamic effects in global climate model simulations. The similarity between seasonally moving and fully moving thresholds indicates that seasonal mean warming alone can explain large parts of the warming of extremes. The strong sensitivity of simulated future heatwaves to hazard thresholds should be considered in the projections of potential future heat‐related impacts.
Trends in AOD, Clouds, and Cloud Radiative Effects in Satellite Data and CMIP5 and CMIP6 Model Simulations Over Aerosol Source Regions
Authors: Cherian Ribu , Quaas Johannes 
Published: April 2020

AbstractSeveral regions worldwide have seen significant trends in anthropogenic aerosol emissions during the period of detailed satellite observations since 2001. Over Europe (EUR) and North America (NAM) there were strong declines, over China increases then declines and over India, strong increases. Regional trends in model‐simulated aerosol optical depth (AOD) and cloud radiative effects in both the Fifth and Sixth Coupled Model Intercomparison Projects (CMIP5 and CMIP6) are broadly consistent with the ones from satellite retrievals in most parts of EUR, NAM and India. CMIP6 models better match satellite‐derived AOD trend in western NAM (increasing) and eastern China (decreasing), where CMIP5 models failed, pointing to improved anthropogenic aerosol emissions. Drop concentration trends in both observations and models qualitatively match AOD trends. The result for solar cloud radiative effect in models, however, is due to compensating errors: Models fail to reproduce observed liquid water path trends and show, in turn, opposite trends in cloud fraction.
The Mantle Transition Zone Hosts the Missing HIMU Reservoir Beneath Eastern China
Authors: Qian Sheng‐Ping , Nichols Alexander R. L. , Zhang Le , Xu Yi‐Gang , Li Jie , Guo Yu‐Long , Ren Zhong‐Yuan 
Published: April 2020

AbstractThe Earth's mantle shows large‐scale geochemical heterogeneities bounded by several identifiable end‐member compositions. However, the origin of extreme mantle reservoirs, for example, high 238U/204Pb (HIMU), and their location in the Earth's interior remains poorly constrained. Clinopyroxenes from late Cenozoic Wudi lavas in eastern China have heterogeneous Pb isotopic compositions, even though the erupted lavas are isotopically homogeneous. Our new results provide, to our knowledge, the first evidence for the existence of a HIMU‐like component in the sources of late Cenozoic lavas. Analyses of olivines and their host lavas indicate that the basaltic melts are derived from partial melting of carbonated peridotite. The HIMU source is likely to be younger than 700 Ma old and related to subduction events of the Paleo‐Asian ocean. In addition to deep and ancient recycling, storage of a metasomatically produced mantle reservoir in the mantle transition zone may be an important mechanism for developing extreme isotopic signatures.
A Framework for Understanding and Quantifying the Loss and Acceleration of Relativistic Electrons in the Outer Radiation Belt During Geomagnetic Storms
Authors: Murphy Kyle R. , Mann Ian R. , Sibeck David G. , Rae I. Jonathan , Watt C.E.J. , Ozeke Louis G. , Kanekal Shri G. , Baker Daniel N. 
Published: April 2020

AbstractWe present detailed analysis of the global relativistic electron dynamics as measured by total radiation belt content (RBC) during coronal mass ejection (CME) and corotating interaction region (CIR)‐driven geomagnetic storms. Recent work has demonstrated that the response of the outer radiation belt is consistent and repeatable during geomagnetic storms. Here we build on this work to show that radiation belt dynamics can be divided into two sequential phases, which have different solar wind dependencies and which when analyzed separately reveal that the radiation belt responds more predictably than if the overall storm response is analyzed as a whole. In terms of RBC, in every storm we analyzed, a phase dominated by loss is followed by a phase dominated by acceleration. Analysis of the RBC during each of these phases demonstrates that they both respond coherently to solar wind and magnetospheric driving. However, the response is independent of whether the storm response is associated with either a CME or CIR. Our analysis shows that during the initial phase, radiation belt loss is organized by the location of the magnetopause and the strength of Dst and ultralow frequency wave power. During the second phase, radiation belt enhancements are well organized by the amplitude of ultralow frequency waves, the auroral electroject index, and solar wind energy input. Overall, our results demonstrate that storm time dynamics of the RBC is repeatable and well characterized by solar wind and geomagnetic driving, albeit with different dependencies during the two phases of a storm.
Biallelic mutations in WRAP53 result in dysfunctional telomeres, Cajal bodies and DNA repair, thereby causing Hoyeraal–Hreidarsson syndrome
Authors: Bergstrand Sofie , Böhm Stefanie , Malmgren Helena , Norberg Anna , Sundin Mikael , Nordgren Ann , Farnebo Marianne 
Published: April 2020

AbstractApproximately half of all cases of Hoyeraal–Hreidarsson syndrome (HHS), a multisystem disorder characterized by bone marrow failure, developmental defects and very short telomeres, are caused by germline mutations in genes related to telomere biology. However, the varying symptoms and severity of the disease indicate that additional mechanisms are involved. Here, a 3-year-old boy with HHS was found to carry biallelic germline mutations in WRAP53 (WD40 encoding RNA antisense to p53), that altered two highly conserved amino acids (L283F and R398W) in the WD40 scaffold domain of the protein encoded. WRAP53β (also known as TCAB1 or WDR79) is involved in intracellular trafficking of telomerase, Cajal body functions and DNA repair. We found that both mutations cause destabilization, mislocalization and faulty interactions of WRAP53β, defects linked to misfolding by the TRiC chaperonin complex. Consequently, WRAP53β HHS mutants cannot elongate telomeres, maintain Cajal bodies or repair DNA double-strand breaks. These findings provide a molecular explanation for the pathogenesis underlying WRAP53β-associated HHS and highlight the potential contribution of DNA damage and/or defects in Cajal bodies to the early onset and/or severity of this disease.
The cellular prion protein is a stress protein secreted by renal tubular cells and a urinary marker of kidney injury
Authors: Bignon Yohan , Poindessous Virginie , Lazareth Hélène , Passet Bruno , Vilotte Jean-Luc , Djouadi Fatima , Mouillet-Richard Sophie , Pallet Nicolas 
Published: April 2020

AbstractEndoplasmic Reticulum (ER) stress underlies the pathogenesis of numerous kidney diseases. A better care of patients with kidney disease involves the identification and validation of ER stress biomarkers in the early stages of kidney disease. For the first time to our knowledge, we demonstrate that the prion protein PrPC is secreted in a conventional manner by ER-stressed renal epithelial cell under the control of the transcription factor x-box binding protein 1 (XBP1) and can serve as a sensitive urinary biomarker for detecting tubular ER stress. Urinary PrPC elevation occurs in patients with chronic kidney disease. In addition, in patients undergoing cardiac surgery, detectable urine levels of PrPC significantly increase after cardiopulmonary bypass, a condition associated with activation of the IRE1-XBP1 pathway in the kidney. In conclusion, our study has identified PrPC as a novel urinary ER stress biomarker with potential utility in early diagnosis of ongoing acute or chronic kidney injury.
Age related retinal Ganglion cell susceptibility in context of autophagy deficiency
Authors: Bell Katharina , Rosignol Ines , Sierra-Filardi Elena , Rodriguez-Muela Natalia , Schmelter Carsten , Cecconi Francesco , Grus Franz , Boya Patricia 
Published: April 2020

AbstractGlaucoma is a common age-related disease leading to progressive retinal ganglion cell (RGC) death, visual field defects and vision loss and is the second leading cause of blindness in the elderly worldwide. Mitochondrial dysfunction and impaired autophagy have been linked to glaucoma and induction of autophagy shows neuroprotective effects in glaucoma animal models. We have shown that autophagy decreases with aging in the retina and that autophagy can be neuroprotective for RGCs, but it is currently unknown how aging and autophagy deficiency impact RGCs susceptibility and survival. Using the optic nerve crush model in young and olWelcome@1234d Ambra1+/gt (autophagy/beclin-1 regulator 1+/gt) mice we analysed the contribution of autophagy deficiency on retinal ganglion cell survival in an age dependent context. Interestingly, old Ambra1+/gt mice showed decreased RGC survival after optic nerve crush in comparison to old Ambra1+/+, an effect that was not observed in the young animals. Proteomics and mRNA expression data point towards altered oxidative stress response and mitochondrial alterations in old Ambra1+/gt animals. This effect is intensified after RGC axonal damage, resulting in reduced oxidative stress response showing decreased levels of Nqo1, as well as failure of Nrf2 induction in the old Ambra1+/gt. Old Ambra1+/gt also failed to show increase in Bnip3l and Bnip3 expression after optic nerve crush, a response that is found in the Ambra1+/+ controls. Primary RGCs derived from Ambra1+/gt mice show decreased neurite projection and increased levels of apoptosis in comparison to Ambra1+/+ animals. Our results lead to the conclusion that oxidative stress response pathways are altered in old Ambra1+/gt mice leading to impaired damage responses upon additional external stress factors.
Corded Ware cultural complexity uncovered using genomic and isotopic analysis from south-eastern Poland
Authors: Linderholm Anna , Kılınç Gülşah Merve , Szczepanek Anita , Włodarczak Piotr , Jarosz Paweł , Belka Zdzislaw , Dopieralska Jolanta , Werens Karolina , Górski Jacek , Mazurek Mirosław , Hozer Monika , Rybicka Małgorzata , Ostrowski Mikołaj , Bagińska Jolanta , Koman Wiesław , Rodríguez-Varela Ricardo , Storå Jan , Götherström Anders , Krzewińska Maja 
Published: April 2020

AbstractDuring the Final Eneolithic the Corded Ware Complex (CWC) emerges, chiefly identified by its specific burial rites. This complex spanned most of central Europe and exhibits demographic and cultural associations to the Yamnaya culture. To study the genetic structure and kin relations in CWC communities, we sequenced the genomes of 19 individuals located in the heartland of the CWC complex region, south-eastern Poland. Whole genome sequence and strontium isotope data allowed us to investigate genetic ancestry, admixture, kinship and mobility. The analysis showed a unique pattern, not detected in other parts of Poland; maternally the individuals are linked to earlier Neolithic lineages, whereas on the paternal side a Steppe ancestry is clearly visible. We identified three cases of kinship. Of these two were between individuals buried in double graves. Interestingly, we identified kinship between a local and a non-local individual thus discovering a novel, previously unknown burial custom.
Simultaneous enhancement of thermoelectric and mechanical performance for SnTe by nano SiC compositing
Authors: Wang Teng , Wang Hongchao , Su Wenbin , Zhai Jinze , Yakovleva Galina , Wang Xue , Chen Tingting , Romanenko Anatoly , Wang Chunlei 
Published: April 2020

SiC is firstly introduced into SnTe. The created lattice mismatch and interfaces via hand milling are responsible for the enhanced zT, which is comparable with doped samples. Besides, the hardness of samples is got improved with SiC compositing.