bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Review of the Scope of Artisanal and Small‐Scale Mining Worldwide, Poverty, and the Associated Health Impacts
Authors: Schwartz Franklin W. , Lee Sangsuk , Darrah Thomas H. 
Published: January 2021

AbstractSome of the poorest people in the world's poorest countries eke out a living in artisanal and small‐scale mining (ASM). Equipped with primitive tools like picks, shovels, buckets, and gold pans, they work mining valuable resources, like gold, diamonds, tin, lithium, rare earth elements, tantalum, and cobalt, and any other usable commodity, for example, sand, coal, or mica. The mining and refining processes are labor intensive and associated with a variety of health problems due to accidents, overheating, overexertion, dust inhalation, exposure to toxic chemicals and gases, violence, and illicit and prescription drug and alcohol addiction. Evident disadvantages with ASM are counterbalanced by the immense economic benefits. For many, the true scope and scale of ASM activities are unappreciated, along with the unknown health and societal impacts. Here, we set out to elucidate the scope of ASM beyond the recovery of familiar commodities, such as gold and diamonds. We adopt a holistic perspective toward health impacts of ASM, which includes unique occupational, environmental, and human/social drivers. A particular focus is poverty as a health risk with artisanal miners. They are commonly poverty‐stricken people in poor countries, ensnared by a variety of poverty traps, which take a toll on the health and well‐being of individuals and communities. ASM sometimes provides an opportunity to diversify income in the face of a decline in subsistence agriculture. However, ASM often trades one kind of generational poverty for another, coming along with serious health risks and turmoil associated with work in an informal “cash‐rich” business.
Gap Formation Around 0.5Ωe of Whistler‐Mode Waves Excited by Electron Temperature Anisotropy
Authors: Chen Huayue , Gao Xinliang , Lu Quanming , Sauer Konrad , Chen Rui , Yao Jiansheng , Wang Shui 
Published: January 2021

AbstractWith a one‐dimensional particle‐in‐cell simulation model, we have investigated the gap formation around 0.5 of the quasi‐parallel whistler‐mode waves excited by an electron temperature anisotropy. When the frequencies of excited waves in the linear stage cross 0.5, or when they are slightly larger than 0.5 but then drift to lower values, the Landau resonance can make the electron distribution form a beam‐like/plateau population. Such an electron distribution only slightly changes the dispersion relation of whistler‐mode waves, but can cause severe damping around 0.5 via cyclotron resonance. At last, the wave spectrum is separated into two bands with a power gap around 0.5. The condition under different electron temperature anisotropy and plasma beta is also surveyed for such kind of power gap. Besides, when only the waves with frequencies lower than 0.5 are excited in the linear stage, a power gap can also be formed due to the wave‐wave interactions, i.e., lower band cascade. Our study provides a clue to reveal the well‐known 0.5 power gap of whistler‐mode waves ubiquitously observed in the inner magnetosphere.
Structure and Coalescence of Magnetopause Flux Ropes and Their Dependence on IMF Clock Angle: Three‐Dimensional Global Hybrid Simulations
Authors: Guo Jin , Lu San , Lu Quanming , Lin Yu , Wang Xueyi , Huang Kai , Wang Rongsheng , Wang Shui 
Published: January 2021

AbstractFlux ropes are ubiquitous at Earth's magnetopause and play important roles in energy transport between the solar wind and Earth's magnetosphere. In this study, structure and coalescence of the magnetopause flux ropes formed by multiple X line reconnection in cases with different southward interplanetary magnetic field (IMF) clock angles are investigated by using three‐dimensional global hybrid simulations. As the IMF clock angle decreases from 180°, the axial direction of the flux ropes becomes tilted relative to the equatorial plane, the length of the flux ropes gradually increases, and core field within flux ropes is formed by the increase in the guide field. The flux ropes are formed mostly near the subsolar point and then move poleward toward cusps. The flux ropes can eventually enter the cusps, during which their helical structure collapses, their core field weakens gradually, and their axial length decreases. When the IMF clock angle is large (i.e., the IMF is predominantly southward), the flux ropes can coalesce and form new ones with larger diameter. The coalescence between flux ropes can occur both near the subsolar point when they are newly formed and away from the subsolar point (e.g., in the southern hemisphere) when they move toward cusps. However, when the IMF clock angle is small (≤135°), we do not find coalescence between flux ropes.
Observations and Simulations of the Peak Response Time of Thermospheric Mass Density to the 27‐Day Solar EUV Flux Variation
Authors: Ren Dexin , Lei Jiuhou , Wang Wenbin , Burns Alan , Luan Xiaoli 
Published: January 2021

AbstractIn this study, the mass densities from Challenging Minisatellite Payload and Gravity Recovery and Climate Experiment satellites and the simulation results from the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) have been used to systematically explore the peak response time (or time delay hereafter) of thermospheric mass density to the 27‐day solar extreme ultraviolet (EUV) flux variation. The TIEGCM can generally reproduce the observed time delay of thermospheric mass density to the 27‐day solar EUV flux changes. The simulation results suggest that the delay of the peak of thermospheric mass density to that of the 27‐day solar EUV flux variation is about 0.9 days. However, geomagnetic activity can significantly affect the derivation of the time delay of thermospheric mass density from the pure solar EUV flux impact. Additionally, the delay of thermospheric mass density to the 27‐day solar EUV flux changes with altitude, latitude, and local time.
The Wave Origins of Longitudinal Structures in ExoMars Trace Gas Orbiter (TGO) Aerobraking Densities
Authors: Forbes Jeffrey M. , Bruinsma Sean , Zhang Xiaoli , Forget Francois , Marty Jean‐Charles , Millour Ehouarn , González‐Galindo Francisco 
Published: January 2021

AbstractThe nature and origins of longitudinal density structures in Mars’ thermosphere between 100 and 120 km altitude, and −30° and −75° latitude around winter solstice (Ls = 70–122°), as measured by the accelerometer on the ExoMars Trace Gas Orbiter (TGO) Mission, are investigated. The methodology consists of deducing the responsible waves by comparing the observed longitude versus local time phase progressions of the structures with those of probable candidate waves in the Mars Climate Database (MCD) climatology. The observed wave‐1, wave‐2, and wave‐3 structures are interpreted as originating mainly from SPW1; (SPW2, S0, DE1); and (SPW3, DE2), respectively, where SPWm denotes a stationary planetary wave with zonal wavenumber s = m, S0 is the zonally symmetric semidiurnal tide, and DE1(DE2) are the eastward‐propagating diurnal tides with s = −1(−2). All of these waves exist in the MCD with amplitudes as large as those observed, although not wholly in the narrow height‐latitude regime accessed by TGO. This disparity between the MCD and TGO amplitude structures is hypothesized to result from the extreme intrusion of the polar‐region eastward winter jet into the thermosphere in the MCD. The winter polar jet blocks poleward expansion of DE1 and DE2 beyond −30° latitude, and also impacts the structures of SPW2, S0 and SPW3 that arise from in situ nonlinear interaction between DE1 and DE2, respectively, with the diurnal migrating tide (DW1).
Arctic Sea Ice Decline Preconditions Events of Anomalously Low Sea Ice Volume Export Through Fram Strait in the Early 21st Century
Authors: Wang Qiang , Ricker Robert , Mu Longjiang 
Published: January 2021

AbstractUnderstanding the changes of Fram Strait sea ice volume export and responsible processes is crucial due to their climate relevance. In this paper, we disentangled the processes driving the interannual variability and trends of the Fram Strait sea ice volume export in the early 21st century (2001–2019) by using dedicated numerical simulations with the support of observations. The significant decreasing trend in the sea ice volume export is caused by the persistent thinning trend of Arctic sea ice, while the interannual variability of the volume export is predominantly determined by winds. The interannual variability of the volume export can be mainly attributed to the variation in sea ice drift at Fram Strait, while the variation in Fram Strait sea ice thickness also plays an important role. As a result, the atmospheric mode that can better represent the wind variability driving the variability of both the sea ice drift and thickness at Fram Strait can better explain the variability of the sea ice volume export. The wintertime Arctic Oscillation (AO) and Fram Strait sea ice volume export continue to have a strong linkage in the early 21st century. The persistent thinning of Arctic sea ice preconditions events of anomalously low Fram Strait sea ice volume export. One of the extreme events in recent years occurred in 2017/2018. Variation in winds alone would not have caused such an extreme event without the persistent Arctic sea ice thinning.
Constraining the Decline of the Lunar Dynamo Field at ≈3.1 Ga Through Paleomagnetic Analyses of Apollo 12 Mare Basalts
Authors: Strauss B. E. , Tikoo S. M. , Gross J. , Setera J. B. , Turrin B. 
Published: January 2021

AbstractRecent paleomagnetic studies of lunar rocks have suggested that the magnetic field of the Moon reached peak intensities on the order of ≈77 μT between 3.85 billion and 3.56 billion years ago (Ga) and subsequently declined to surface intensities of ≈4 μT by 3.19 Ga. However, this decline in the intensity of the lunar field has only been shown in a small number of samples, presenting challenges for constraint of its timing and thus the dynamo generation mechanisms that could be responsible. We present microscopic and magnetic analyses of Apollo samples 12008, 12009, and 12015, three fine‐grained mare vitrophyre basalts with high magnetic fidelity, indicating that these samples were not magnetized in conditions consistent with a planetary magnetic field exceeding 4–7 μT during their formation. We further report updated radiometric ages for samples 12008 and 12009 and the first‐ever radiometric age for sample 12015, dating this lunar field intensity constraint to ≈3.1 Ga. These data are consistent with results of previous work on the initial decline of the Moon's magnetic field and confirm that the mechanism of lunar dynamo generation changed dramatically between 3.6 and 3.1 Ga.
Early Cretaceous (∼138–134 Ma) Forearc Ophiolite and Tectonomagmatic Patterns in Central Tibet: Subduction Termination and Re‐initiation of Meso‐Tethys Ocean Caused by Collision of an Oceanic Plateau at the Continental Margin?
Authors: Zeng Yun‐Chuan , Xu Ji‐Feng , Chen Jian‐Lin , Wang Bao‐Di , Huang Feng , Xia Xiao‐Ping , Li Ming‐Jian 
Published: January 2021

AbstractThe Bangong‐Nujiang Suture Zone (BNSZ) in central Tibet represents relics of the Meso‐Tethys Ocean that once separated the Lhasa and Qiangtang terranes. When and how this ocean closed has been a matter of debate, and the cause of the uncertainty stems primarily from a lack of consensus as to whether Early Cretaceous ophiolite exists within the BNSZ. New geochronological and geochemical data presented here identify ∼138–134 Ma MORB‐like and OIB‐type mafic rocks in the Kangqiong area of the western BNSZ. These data, together with the spatially associated peridotite and marine sediment, provide the first firm evidence for the presence of Early Cretaceous ophiolite within the BNSZ. Our integrated study of geological, mineralogical, and geochemical data suggests that the Kangqiong Ophiolite formed in a forearc setting related to the subduction re‐initiation of the Meso‐Tethys Ocean. By combining the present results with a synthesis of tectonomagmatism in central Tibet, including the existence of an Early Jurassic oceanic plateau within the Meso‐Tethys Ocean, the magmatic lull (∼145–130 Ma) in the Qiangtang Terrane, an angular unconformity between Lower Jurassic oceanic rocks and Upper Jurassic shallow‐marine strata, and the compositional differences and migration of magmatism before and after the magmatic lull, we propose a new model of the evolution of the Meso‐Tethys Ocean. This model proposes that the collision of an oceanic plateau with the Qiangtang continental margin caused the termination of Meso‐Tethyan subduction during the Late Jurassic and subsequent re‐initiation behind the oceanic plateau during the Early Cretaceous.
Bayesian Hierarchical Modeling of Nitrate Concentration in a Forest Stream Affected by Large‐Scale Forest Dieback
Authors: Jung Hoseung , Senf Cornelius , Beudert Burkhard , Krueger Tobias 
Published: January 2021

AbstractThe ecosystem function of vegetation to attenuate export of nutrients is of substantial importance for securing water quality. This ecosystem function is at risk of deterioration due to an increasing risk of large‐scale forest dieback under climate change. The present study explores the response of the nitrogen (N) cycle of a forest catchment in the Bavarian Forest National Park, Germany, in the face of a severe bark beetle (Ips typographus Linnaeus) outbreak and resulting large‐scale forest dieback using top‐down statistical‐mechanistic modeling. Outbreaks of bark beetle killed the dominant tree species Norway spruce (Picea abies (L.) H.Karst.) in stands accounting for 55% of the catchment area. A Bayesian hierarchical model that predicts daily stream NO3 concentration (C) over three decades with discharge (Q) and temperature (T) (C‐Q‐T relationship) outperformed alternative statistical models. A catchment model was subsequently developed to explain the C‐Q‐T relationship in top‐down fashion. Annually varying parameter estimates provide mechanistic interpretations of the catchment processes. Release of NO3 from decaying litter after the dieback was tracked by an increase of the nutrient input parameter cs0. The slope of C‐T relation was near zero during this period, suggesting that the nutrient release was beyond the regulating capacity of the vegetation and soils. Within a decade after the dieback, the released N was flushed out and nutrient retention capacity was restored with the regrowth of the vegetation.
Deep‐Learning‐Based Adjoint State Method: Methodology and Preliminary Application to Inverse Modeling
Authors: Xiao Cong , Deng Ya , Wang Guangdong 
Published: January 2021

AbstractWe present an efficient adjoint model based on the deep‐learning surrogate to address high‐dimensional inverse modeling with an application to subsurface transport. The proposed method provides a completely code nonintrusive and computationally feasible way to approximate the model derivatives, which subsequently can be used to derive gradients for inverse modeling. This conceptual deep‐learning framework, that is, an architecture of deep convolutional neural network through combining autoencoder and autoregressive structure, efficiently produces an analogously analytical adjoint with the help of auto‐differentiation module in the popular deep‐learning packages. We intentionally retain training data at the specific time instances where the measurements are taken, the storage of the intermediate states and computation of their adjoint, therefore, are completely avoided. This proposed adjoint state method is tested on a synthetic two‐dimensional model for parameter estimations. The preliminary results reveal the feasibility of the proposed adjoint state method in term of computational efficiency and programming flexibility.
Assessing the Feasibility of Managed Aquifer Recharge in California
Authors: Ulibarri Nicola , Escobedo Garcia Nataly , Nelson Rebecca L. , Cravens Amanda E. , McCarty Ryan J. 
Published: January 2021

AbstractWith aquifers around the world stressed by over‐extraction, water managers are increasingly turning to managed aquifer recharge (MAR), directly replenishing groundwater resources through injection wells, recharge basins, or other approaches. While there has been progress in understanding the geological and infrastructure‐related considerations to make MAR more effective, critical evaluations of its institutional design and implementation are limited. This study assesses MAR projects, using a case study of projects proposed by groundwater sustainability agencies (GSAs) in California to comply with the state's Sustainable Groundwater Management Act of 2014; these projects will almost double the number of MAR projects in the United States. We draw on content analysis of groundwater sustainability plans that propose these projects. We first assess the types of recharge projects proposed and the stated aims of the projects, to assess when and why agencies are turning to MAR as a solution. We find that recharge basins are by far the most common approach, and that GSAs hope these basins will improve water table levels, reduce subsidence, and improve water quality. We then analyze potential barriers to project implementation and assess the projects' ability to achieve the stated goals. Primary concerns identified include a potential lack of available water, a potentially challenging legal framework, and minimal consideration of funding and cumulative land needs. To conclude, we discuss broader considerations for ensuring that MAR is an effective water management tool.
22(R)-hydroxycholesterol for dopaminergic neuronal specification of MSCs and amelioration of Parkinsonian symptoms in rats
Authors: Singh Manisha , Jain Manish , Bose Samrat , Halder Ashutosh , Nag Tapas Chandra , Dinda Amit Kumar , Mohanty Sujata 
Published: January 2021

AbstractOxysterols play vital roles in the human body, ranging from cell cycle regulation and progression to dopaminergic neurogenesis. While naïve human mesenchymal stem cells (hMSCs) have been explored to have neurogenic effect, there is still a grey area to explore their regenerative potential after in vitro differentiation. Hence, in the current study, we have investigated the neurogenic effect of 22(R)-hydroxycholesterol (22-HC) on hMSCs obtained from bone marrow, adipose tissue and dental pulp. Morphological and morphometric analysis revealed physical differentiation of stem cells into neuronal cells. Detailed characterization of differentiated cells affirmed generation of neuronal cells in culture. The percentage of generation of non-DA cells in the culture confirmed selective neurogenic potential of 22-HC. We substantiated the efficacy of these cells in neuro-regeneration by transplanting them into Parkinson’s disease Wistar rat model. MSCs from dental pulp had maximal regenerative effect (with 80.20 ± 1.5% in vitro differentiation efficiency) upon transplantation, as shown by various behavioural examinations and immunohistochemical tests. Subsequential analysis revealed that 22-HC yields a higher percentage of functional DA neurons and has differential effect on various tissue-specific primary human MSCs. 22-HC may be used for treating Parkinson’s disease in future with stem cells.
Filter-free color image sensor based on CsPbBr3−3nX3n (X = Cl, I) single crystals
Authors: Zhang Peng , Hua Yunqiu , Li Xiang , Zhang Longzhen , Liu Lin , Li Rongzhen , Zhang Guodong , Tao Xutang 
Published: January 2021

Centimeter-sized CsPbBr3−3nX3n single crystals were grown using the modified Bridgman method. Eight filter-free narrowband photodetectors were fabricated based on the CsPbBr3−3nX3n crystals utilizing the concept of charge collection narrowing. A filter-free color image sensor was constructed using these eight CsPbBr3−3nX3n narrowband photodetectors.
Long‐time coherent integration based on intra‐partition range‐Doppler processing for passive bistatic radar
Authors: Zuo Luo , Wang Jun , Sui Jinxin 
Published: January 2021

AbstractThe Doppler mismatch, range migration and Doppler frequency migration (DFM) correction problem for realizing the long‐time coherent integration of space moving target with high‐speed manoeuvring performance in passive bistatic radar is considered. A novel method based on intra‐partition range‐Doppler (RD) processing is proposed, where the intra‐partition RD processing is first performed to achieve the pre‐accumulation of target’s energy in each partition and eliminate the Doppler mismatch. Then, the generalized keystone transform is employed to correct the range curvature. After that, the residual range walk is removed with the centre frequency of the coarse Doppler filter related to the target velocity. Furthermore, matched filtering process is carried out to compensate the DFM. The advantage of the method is that it can obtain superior coherent integration and detection performance in comparison with the existing algorithms. Numerical simulations are presented to demonstrate the coherent integration and the detection performance for a high‐speed target.
The OTELO survey as a morphological probe. Last ten Gyr of galaxy evolution
Authors: Nadolny Jakub , Bongiovanni Ángel , Cepa Jordi , Cerviño Miguel , Pérez García Ana María , Pović Mirjana , Pérez Martínez Ricardo , Sánchez-Portal Miguel , de Diego José A. , Pintos-Castro Irene , Alfaro Emilio , Castañeda Héctor O. , Gallego Jesús , Jesús González J. , Ignacio González-Serrano J. , Lara-López Maritza A. , Padilla Torres Carmen P. 
Published: January 2021

Context. The morphology of galaxies provide us with a unique tool for relating and understanding other physical properties and their changes over the course of cosmic time. It is only recently that we have been afforded access to a wealth of data for an unprecedented number galaxies thanks to large and deep surveys.
Aims. We present the morphological catalogue of the OTELO survey galaxies detected with the Hubble Space Telescope (HST)-ACS F814W images. We explore various methods applied in previous works to separate early-type (ET) and late-type (LT) galaxies classified via spectral energy distribution (SED) fittings using galaxy templates. Together with this article, we are releasing a catalogue containing the main morphological parameters in the F606W and F814W bands derived for more than 8000 sources.
Methods. The morphological analysis is based on the single-Sérsic profile fit. We used the GALAPAGOS2 software to provide multi-wavelength morphological parameters fitted simultaneously in two HST-ACS bands. The GALAPAGOS2 software detects, prepares guess values for GALFIT-M, and provides the best-fitting single-Sérsic model in both bands for each source. Stellar masses were estimated using synthetic rest-frame magnitudes recovered from SED fittings of galaxy templates. The morphological catalogue is complemented with concentration indexes from a separate SExtractor dual, high dynamical range mode.
Results. A total of 8812 sources were successfully fitted with single-Sérsic profiles. The analysis of a carefully selected sample of ∼3000 sources up to zphot = 2 is presented in this work, of which 873 sources were not detected in previous studies. We found no statistical evidence for the evolution of the low-mass end of mass–size relation for ET and LT since z = 2. Furthermore, we found a good agreement for the median size evolution for ET and LT galaxies, for a given stellar mass, with the data from the literature. Compared to previous works on faint field galaxies, we found similarities regarding their rest-frame colours as well as the Sérsic and concentration indices.