bluuebunny/crossref_metadata_2025_split huggingface dataset:
Patterns and Distributions of Urban Expansion in Global Watersheds
Authors: Huang Qingxu , Zhang Han , van Vliet Jasper , Ren Qiang , Wang Raymond Yu , Du Shiqiang , Liu Zhifeng , He Chunyang 
Published: July 2021

AbstractUnderstanding urban expansion at the watershed scale is important because watersheds are important carriers of ecological and environmental impacts. However, current analyses are mainly restricted to administrative units only. Here, we used a long‐term multitemporal data set of urban land to quantify the spatiotemporal trends in the extent and form of urban expansion from 1992 to 2016 in endorheic and exoreic watersheds, globally. Overall, urban expansion in 70% of watersheds (154/220) showed a decelerating trend. The average urban expansion speed of these watersheds in the last 6 years was approximately half of that in the last 24 years. Urban expansion speed in endorheic watersheds lagged behind the counterparts in exoreic watersheds, with the former approximately 1/4 of the latter. More importantly, the pattern of urban expansion in endorheic watersheds was following the low‐density and sprawling trend in exoreic watersheds, which could exert far‐reaching impacts on the sustainability of endorheic watersheds located in arid lands. These findings suggest the need to look beyond administrative city boundaries for land use planning and policies in the context of watershed management.
Air Pollution From Forest and Vegetation Fires in Southeast Asia Disproportionately Impacts the Poor
Authors: Reddington Carly L. , Conibear Luke , Robinson Suzanne , Knote Christoph , Arnold Stephen R. , Spracklen Dominick V. 
Published: July 2021

AbstractForest and vegetation fires, used as tools for agriculture and deforestation, are a major source of air pollutants and can cause serious air quality issues in many parts of Asia. Actions to reduce fire may offer considerable, yet largely unrecognized, options for rapid improvements in air quality. In this study, we used a combination of regional and global air quality models and observations to examine the impact of forest and vegetation fires on air quality degradation and public health in Southeast Asia (including Mainland Southeast Asia and south‐eastern China). We found that eliminating fire could substantially improve regional air quality across Southeast Asia by reducing the population exposure to fine particulate matter (PM2.5) concentrations by 7% and surface ozone concentrations by 5%. These reductions in PM2.5 exposures would yield a considerable public health benefit across the region; averting 59,000 (95% uncertainty interval (95UI): 55,200–62,900) premature deaths annually. Analysis of subnational infant mortality rate data and PM2.5 exposure suggested that PM2.5 from fires disproportionately impacts poorer populations across Southeast Asia. We identified two key regions in northern Laos and western Myanmar where particularly high levels of poverty coincide with exposure to relatively high levels of PM2.5 from fires. Our results show that reducing forest and vegetation fires should be a public health priority for the Southeast Asia region.
Stable Atlantic Deep Water Mass Sourcing on Glacial‐Interglacial Timescales
Authors: Pöppelmeier Frerk , Gutjahr Marcus , Blaser Patrick , Schulz Hartmut , Süfke Finn , Lippold Jörg 
Published: July 2021

AbstractIncreased deep ocean carbon storage is often invoked as the major sink for lower atmospheric CO2 concentrations during past ice ages. In order to improve the understanding of the changes in ocean dynamics facilitating such increased oceanic carbon storage, we assess the variability of deep water provenance in the Atlantic by reconstructing authigenic Nd isotopes from North Atlantic site U1313 over the past ∼100 kyr. Under consideration of these new constraints for the northern Nd isotope end‐member, we find only limited long‐term variations in the meridional and intra‐basin water‐mass gradients suggesting a prevalence of northern‐sourced water (NSW) throughout the past 100 kyr. Tentative results suggest that during the glacial period of Marine Isotope Stage 4 NSW proportions even increased by additional ∼15% in the equatorial and Northeast Atlantic, calling into question the notion that cold climates promote the expansion of southern‐sourced water.
Upper‐Hybrid Waves Driven by Meandering Electrons Around Magnetic Reconnection X Line
Authors: Li W.‐Y. , Khotyaintsev Yu V. , Tang B.‐B. , Graham D. B. , Norgren C. , Vaivads A. , André M. , Le A. , Egedal J. , Dokgo K. , Fujimoto K. , He J.‐S. , Burch J. L. , Lindqvist P.‐A. , Ergun R. E. , Torbert R. B. , Le Contel O. , Gershman D. J. , Giles B. L. , Lavraud B. , Fuselier S. , Plaschke F. , Russell C. T. , Guo X.‐C. , Lu Q.‐M. , Wang C. 
Published: July 2021

AbstractMagnetic reconnection is a fundamental process in collisionless space plasma environment, and plasma waves relevant to the kinetic interactions can have a significant impact on the multiscale behavior of reconnection. Here, we present Magnetospheric Multiscale (MMS) observations during an encounter of an X line of symmetric magnetic reconnection in the magnetotail. The X line is characterized by reversals of ion and electron jets and electromagnetic fields, agyrotropic electron velocity distribution functions (VDFs), and an electron‐scale current sheet. MMS observe large‐amplitude nonlinear upper‐hybrid (UH) waves on both sides of the neutral line, and the wave amplitudes have highly localized distribution along the normal direction. The inbound meandering electrons drive the UH waves, releasing the free energy stored from the reconnection electric field along the meandering trajectories. The interaction between the meandering electrons and the UH waves may modify the balance of the reconnection electric field around the X line.
Examining the Role of Cloud Radiative Interactions in Tropical Cyclone Development Using Satellite Measurements and WRF Simulations
Authors: Wu S.‐N. , Soden B. J. , Nolan D. S. 
Published: July 2021

AbstractThis study examines the role of cloud‐radiative interactions in the development of tropical cyclones using satellite measurements and model simulations. Previous modeling studies have found that the enhanced cloud radiative heating from longwave radiation in the convective region plays a key role in promoting the development of tropical convective systems. Here, we use satellite measurements and Weather Research and Forecasting Model (WRF) simulations to further investigate how critical cloud radiative interactions are to the development of tropical cyclones (TCs). Clouds and the Earth's Radiant Energy System measurements show that intensifying TCs have greater radiative heating from clouds within the TC area than weakening ones. Based on this result, idealized WRF simulations are performed to examine the importance of the enhanced radiative heating to TC intensification. Sensitivity experiments demonstrate that removing cloud‐radiative interactions often inhibits tropical cyclogenesis, suggesting that cloud‐radiative interactions play a critical role.
Enigmatic Mid‐Proterozoic Orogens: Hot, Thin, and Low
Authors: Spencer Christopher J. , Mitchell Ross N. , Brown Michael 
Published: July 2021

AbstractSince the Archean, secular change in orogenic style is demonstrated through evolution of metamorphic conditions and geochemical proxies. Linked to orogenic style is the amount of crustal thickening and elevation, whereas orogenic vigor is related to the supercontinent cycle. An array of Proterozoic orogens spanned the assembly of supercontinents Columbia and Rodinia, but the vigor of orogenesis is debated, with proposals for both Mesoproterozoic quiescence and climax. We show mid‐Proterozoic orogenesis occurred globally and was broadly continuous; furthermore, orogens exhibit elevated metamorphic thermobaric ratios with large volumes of high‐temperature felsic magmatic rocks. These features reflect higher mantle heat flux leading to increased mid‐crustal flow and lower elevation. In this context, proposals that geochemical proxies for crustal thickness record orogenic quiescence are inconsistent with the geological record. Alternatively, secular change in crustal thickness is attributed to orogenic style, namely the prevalence of hot, thin, and low orogens in the mid‐Proterozoic.
Linear Response Function Reveals the Most Effective Remote Forcing in Causing September Arctic Sea Ice Melting in CESM
Authors: Wu Yutian , Lu Jian , Ding Qinghua , Liu Fukai 
Published: July 2021

AbstractWe apply the linear response function to investigate the most excitable mode of the September Arctic sea ice in the Community Earth System Model. We find that this sea ice mode preferentially takes place over the Pacific side of the Arctic and its remote forcing corresponds to a dipole pattern of precipitation anomaly in the tropics with an increase of precipitation over the western and central tropical Pacific ocean while a decrease over the Maritime Continent. The tropical precipitation anomaly likely drives a Rossby wave train propagating toward the higher latitudes and leads to a ridge anomaly over the Pacific side of the Arctic, resulting in poleward atmospheric heat transport, enhanced downward longwave radiation and thus melting of the sea ice. In addition, a good agreement is found with the leading tropical‐Arctic teleconnection mode in a pre‐industrial simulation, supporting the usefulness and robustness of the linear response function method.
The Footprint Characteristics of Cosmic Ray Thermal Neutrons
Authors: Jakobi J. , Huisman J. A. , Köhli M. , Rasche D. , Vereecken H. , Bogena H. R. 
Published: July 2021

AbstractThe advance of the cosmic ray neutron (CRN) sensing method for estimating field scale soil moisture relied largely on simulations of the footprint properties of epithermal neutrons (∼0.5 eV–100 keV). Commercially available CRN probes are usually additionally equipped with a thermal neutron (<0.5 eV) detector. The potential of these measurements is rarely explored because relevant features of thermal neutrons, such as the footprint and the sensitivity to soil moisture are unknown. Here, we used neutron transport modeling and a river crossing experiment to assess the thermal neutron footprint. We found that the horizontal thermal neutron footprint ranges between 43 and 48 m distance from the probe and that the vertical footprint extends to soil depths between 10 and 65 cm depending on soil moisture. Furthermore, we derived weighting functions that quantify the footprint characteristics of thermal neutrons. These results will enable new applications of thermal neutrons.
Shallowing Glacial Antarctic Intermediate Water by Changes in Sea Ice and Hydrological Cycle
Authors: Li Lingwei , Liu Zhengyu , Zhu Chenyu , He Chengfei , Otto‐Bliesner Bette 
Published: July 2021

AbstractThe Antarctic Intermediate Water (AAIW) is an essential global ocean water mass at intermediate depths. Coupled climate models in isotope‐enabled (δ18O, δD), fully coupled Community Earth System Model and Paleoclimate Model Intercomparison Project Phase 3 consistently show shallower AAIW depth at the Last Glacial Maximum (LGM) due to the northward shift of AAIW. More importantly, modeling results suggest that the northward shift of AAIW can be caused by sea ice expansion and the weakened hydrological cycle under the glacial climate. On the contrary, the AAIW under global warming tends to shift poleward compared to the pre‐industrial period driven by the retreating sea ice and strengthened hydrological cycle. However, the AAIW depth will shallow in response to the ongoing warming, likely due to the overwhelming effects of enhanced stratification and shallowing mixed layer.
Spring‐Fall Asymmetry in VLF Amplitudes Recorded in the North Atlantic Region: The Fall‐Effect
Authors: Macotela E. L. , Clilverd M. , Renkwitz T. , Chau J. , Manninen J. , Banyś D. 
Published: July 2021

AbstractA spring‐fall asymmetry is observed in daytime amplitude values of very low frequency (VLF) radio wave signals propagating over the North Atlantic during 2011–2019. We explore the processes behind this asymmetry by comparing against mesospheric mean temperatures and the semidiurnal solar tide (S2) in mesospheric winds. The solar radiation influence on VLF subionospheric propagation was removed from the daytime VLF amplitude values, isolating the fall‐effect. Similarly, the symmetric background level was removed from mesospheric mean temperatures undertaking comparable analysis. During fall, all three analyzed parameters experience significant deviation from their background levels. The VLF amplitude variation during spring is explained by the seasonal variation in solar illumination conditions, while the fall‐effect can be interpreted as a mean zonal wind reversal associated with both a S2 enhancement, and temperature reductions. Decreases in temperature can produce decreases in collision frequency, reducing VLF signal absorption, driving the observed VLF asymmetry.
Natural Radiation Shielding on Mars Measured With the MSL/RAD Instrument
Authors: Ehresmann B. , Hassler D. M. , Zeitlin C. , Guo J. , Wimmer‐Schweingruber R. F. , Khaksari S. , Loeffler S. 
Published: July 2021

AbstractProtecting astronauts from the effects of space radiation remains one major stepping stone for the exploration of Mars. Long‐term exposure to radiation can lead to severe health effects and affects allowable mission duration. Mission designs for Mars include the use of radiation shelters that provide additional mass to surround the astronauts. This leads to incoming radiation losing energy through ionization processes. This is important during solar energetic particle events when solar protons can reach the surface with high intensities. Additionally, shelters provide a long‐term reduction of the exposure to galactic cosmic rays. As mass is an important time and cost factor in space travel, using natural sheltering already on Mars is a desirable option. One candidate is to use subterranean lava tubes that provide shelter from the radiation from above. Other options include craters, cliff walls, or rock overhangs. Here, we present the first in situ measurements of radiation sheltering by natural environments on the surface of Mars. The data were acquired with the Radiation Assessment Detector (RAD) on board the Curiosity rover in Gale crater on Mars. We show measurements from when Curiosity was parked close to Butte M12 in the Murray Buttes formation, which blocked out 19% of the surrounding sky view. During this time, from Mars Science Laboratory (MSL) sol 1456–1467, we find a decrease of 4% in the expected dose rate, and a decrease of 7.5% in the neutral particle environment. This proof of principle is an important step to validate plans to use natural sheltering on Mars.
New Detailed Modeling of GICs in the Spanish Power Transmission Grid
Authors: Torta J. M. , Marsal S. , Ledo J. , Queralt P. , Canillas‐Pérez V. , Piña‐Varas P. , Curto J. J. , Marcuello A. , Martí A. 
Published: July 2021

AbstractThe threat of Geomagnetically Induced Currents (GICs) driven by severe Space Weather looms over technological systems such as power grids. Assessing their vulnerability is thus vital to avoid damages or even disruption of the electrical power supply. This endeavor, however, entails an interdisciplinary approach, ranging from the characterization of the geoelectrical structure of the Earth beneath and around the area of interest, or the modeling of the power network from its parameters and topology, and including the validation of the modeling process by means of (direct or indirect) GIC flow measurements. In this paper, we summarize our current achievements focused on mainland Spain, concentrating on the improvements reached after going from a homogeneous Earth's resistivity to an alternative 3D electrical resistivity distribution approach to geoelectric field computation, which is still in progress because new empirical impedance tensors are needed, mainly at sites in the west of the Iberian Peninsula. The second major achievement has come from the addition of the 220 kV level to the network model. The overall improvement has been validated against real GIC data in one area of the country. The new vulnerability maps show that in some nodes the predicted GIC has been substantially reduced by the sum of both effects. The assessment has been carried out down to the level of the individual windings of each transformer, and examples of the estimated GIC flow are given for substations with numerous power transmission lines converging to them at diverse orientations.
Antibody responses after first and second Covid-19 vaccination in patients with chronic lymphocytic leukaemia
Authors: Parry H. , McIlroy G. , Bruton R. , Ali M. , Stephens C. , Damery S. , Otter A. , McSkeane T. , Rolfe H. , Faustini S. , Wall N. , Hillmen P. , Pratt G. , Paneesha S. , Zuo J. , Richter A. , Moss P. 
Published: July 2021

AbstractB-cell chronic lymphocytic leukaemia (CLL) is associated with immunosuppression and patients are at increased clinical risk following SARS-CoV-2 infection. Covid-19 vaccines offer the potential for protection against severe infection but relatively little is known regarding the profile of the antibody response following first or second vaccination. We studied spike-specific antibody responses following first and/or second Covid-19 vaccination in 299 patients with CLL compared with healthy donors. 286 patients underwent extended interval (10–12 week) vaccination. 154 patients received the BNT162b2 mRNA vaccine and 145 patients received ChAdOx1. Blood samples were taken either by venepuncture or as dried blood spots on filter paper. Spike-specific antibody responses were detectable in 34% of patients with CLL after one vaccine (n = 267) compared to 94% in healthy donors with antibody titres 104-fold lower in the patient group. Antibody responses increased to 75% after second vaccine (n = 55), compared to 100% in healthy donors, although titres remained lower. Multivariate analysis showed that current treatment with BTK inhibitors or IgA deficiency were independently associated with failure to generate an antibody response after the second vaccine. This work supports the need for optimisation of vaccination strategy in patients with CLL including the potential utility of booster vaccines.
Correlative multi-scale cryo-imaging unveils SARS-CoV-2 assembly and egress
Authors: Mendonça Luiza , Howe Andrew , Gilchrist James B. , Sheng Yuewen , Sun Dapeng , Knight Michael L. , Zanetti-Domingues Laura C. , Bateman Benji , Krebs Anna-Sophia , Chen Long , Radecke Julika , Li Vivian D. , Ni Tao , Kounatidis Ilias , Koronfel Mohamed A. , Szynkiewicz Marta , Harkiolaki Maria , Martin-Fernandez Marisa L. , James William , Zhang Peijun 
Published: July 2021

AbstractSince the outbreak of the SARS-CoV-2 pandemic, there have been intense structural studies on purified viral components and inactivated viruses. However, structural and ultrastructural evidence on how the SARS-CoV-2 infection progresses in the native cellular context is scarce, and there is a lack of comprehensive knowledge on the SARS-CoV-2 replicative cycle. To correlate cytopathic events induced by SARS-CoV-2 with virus replication processes in frozen-hydrated cells, we established a unique multi-modal, multi-scale cryo-correlative platform to image SARS-CoV-2 infection in Vero cells. This platform combines serial cryoFIB/SEM volume imaging and soft X-ray cryo-tomography with cell lamellae-based cryo-electron tomography (cryoET) and subtomogram averaging. Here we report critical SARS-CoV-2 structural events – e.g. viral RNA transport portals, virus assembly intermediates, virus egress pathway, and native virus spike structures, in the context of whole-cell volumes revealing drastic cytppathic changes. This integrated approach allows a holistic view of SARS-CoV-2 infection, from the whole cell to individual molecules.
Semiconductor thermionics for next generation solar cells: photon enhanced or pure thermionic?
Authors: Rahman Ehsanur , Nojeh Alireza 
Published: July 2021

AbstractSemiconductors have been used in solar energy conversion for decades based on the photovoltaic effect. An important challenge of photovoltaics is the undesired heat generated within the device. An alternative approach is thermionics, which uses the thermal excitation of electrons from an emitter to a collector across a vacuum gap. If the emitter is a p-type semiconductor, the photogeneration-induced quasi-Fermi level splitting can reduce the effective barrier for electron emission—a mechanism used by a photon enhanced thermionic emission device. Here, we evaluate the prospects of this alternative solar conversion technology considering different semiconductor materials and thermionic device configurations. We also reveal that whether such a device operates in the photon enhanced or purely thermionic mode, depends on the complex interplay among materials properties, device physics and solar concentration level.
Microglia modulate stable wakefulness via the thalamic reticular nucleus in mice
Authors: Liu Hanxiao , Wang Xinxing , Chen Lu , Chen Liang , Tsirka Stella E. , Ge Shaoyu , Xiong Qiaojie 
Published: July 2021

AbstractMicroglia are important for brain homeostasis and immunity, but their role in regulating vigilance remains unclear. We employed genetic, physiological, and metabolomic methods to examine microglial involvement in the regulation of wakefulness and sleep. Microglial depletion decreased stable nighttime wakefulness in mice by increasing transitions between wakefulness and non-rapid eye movement (NREM) sleep. Metabolomic analysis revealed that the sleep-wake behavior closely correlated with diurnal variation of the brain ceramide, which disappeared in microglia-depleted mice. Ceramide preferentially influenced microglia in the thalamic reticular nucleus (TRN), and local depletion of TRN microglia produced similar impaired wakefulness. Chemogenetic manipulations of anterior TRN neurons showed that they regulated transitions between wakefulness and NREM sleep. Their firing capacity was suppressed by both microglial depletion and added ceramide. In microglia-depleted mice, activating anterior TRN neurons or inhibiting ceramide production both restored stable wakefulness. These findings demonstrate that microglia can modulate stable wakefulness through anterior TRN neurons via ceramide signaling.
17O-EPR determination of the structure and dynamics of copper single-metal sites in zeolites
Authors: Bruzzese Paolo Cleto , Salvadori Enrico , Jäger Stefan , Hartmann Martin , Civalleri Bartolomeo , Pöppl Andreas , Chiesa Mario 
Published: July 2021

AbstractThe bonding of copper ions to lattice oxygens dictates the activity and selectivity of copper exchanged zeolites. By 17O isotopic labelling of the zeolite framework, in conjunction with advanced EPR methodologies and DFT modelling, we determine the local structure of single site CuII species, we quantify the covalency of the metal-framework bond and we assess how this scenario is modified by the presence of solvating H216O or H217O molecules. This enables to follow the migration of CuII species as a function of hydration conditions, providing evidence for a reversible transfer pathway within the zeolite cage as a function of the water pressure. The results presented in this paper establish 17O EPR as a versatile tool for characterizing metal-oxide interactions in open-shell systems.