bluuebunny/crossref_metadata_2025 huggingface dataset:
Tellurium in Late Permian‐Early Triassic Sediments as a Proxy for Siberian Flood Basalt Volcanism
Authors: Regelous Marcel , Regelous Anette , Grasby Stephen E. , Bond David P. G. , Haase Karsten M. , Gleißner Stefan , Wignall Paul B.
Published: October 2020

We measured the concentrations of trace elements in Late Permian to Early Triassic sediments from Spitsbergen. High mercury concentrations in sediments from the level of the Permo‐Triassic Mass Extinction (PTME) at this location were previously attributed to the emplacement of the Siberian Traps Large Igneous Province and used to link the timing of volcanism with the record of environmental change and extinction in these sediments. We investigated the use of the moderately to highly volatile, siderophile elements Ni, Zn, Cd, Sb, Te, Re, and Tl as proxies for the intensity of Siberian volcanism. These trace elements, like Hg, have high concentrations in volcanic gas compared to crustal rocks. Tellurium is highly enriched at the PTME, and Te/Th ratios increase by a factor of ∼20 across the PTME, similar to the variation in Hg/total organic carbon (TOC) in the same samples. Te/Th and Hg/TOC values imply that Siberian volcanism initiated at the onset of the PTME, coincident with the start of the δ13Corganic excursion and abrupt warming. Based on Te and Hg, most Siberian volcanism occurred between the two phases of the PTME boundary (a period of less than 100 ky), but also continued into the Early Triassic. The duration of Siberian volcanism inferred from Te/Th and Hg/TOC is shorter than that indicated by recent high‐precision U‐Pb ages of Siberian intrusive and extrusive rocks. Te concentrations and Te/Th ratios in sediments represent a useful new proxy for volcanism, which can be used to link the marine sedimentary record with large volcanic events on land.
Investigating Recent Changes in MJO Precipitation and Circulation in Multiple Reanalyses
Authors: Hsiao Wei‐Ting , Maloney Eric D. , Barnes Elizabeth A.
Published: October 2020

Recent work using CMIP5 models under RCP8.5 suggests that individual multimodel mean changes in precipitation and wind variability associated with the Madden‐Julian oscillation (MJO) are not detectable until the end of the 21st century. However, a decrease in the ratio of MJO circulation to precipitation anomaly amplitude is detectable as early as 2021–2040, consistent with an increase in dry static stability as predicted by weak temperature gradient balance. Here, we examine MJO activity in multiple reanalyses (ERA5, MERRA‐2, and ERA‐20C) and find that MJO wind and precipitation anomaly amplitudes have a complicated time evolution over the record. However, a decrease in the ratio of MJO circulation to precipitation anomaly amplitude is detected over the observational period, consistent with the change in dry static stability. These results suggest that weak temperature gradient theory may be able to help explain changes in MJO activity in recent decades.
Origins of Major Element, Trace Element, and Isotope Garnet Signatures in Mid‐Ocean Ridge Basalts
Authors: Krein Stephanie Brown , Behn Mark Dietrich , Grove Timothy Lynn
Published: October 2020

To investigate whether the source of the globally occurring garnet signature in mid‐ocean ridge basalt (MORB) is “true” (imparted by melting a garnet‐bearing source) or “apparent” (produced without the involvement of garnet), we present the basalt petrogenesis model Petrogen. Petrogen is built on Kinzler and Grove (1992a, https://doi.org/10.1029/91JB02841) and Behn and Grove (2015, https://doi.org/10.1002/2015JB011885) and calculates the major element, trace element, and isotopic compositions of primary lherzolite‐saturated mantle melts and their subsequent evolution to eruption. This model is experimentally calibrated for melting in the plagioclase, spinel, and garnet fields with and without small amounts of water. Petrogen predicts that garnet‐lherzolite melting requires small mantle porosity (ϕ = ∼0.1%) and enriched (NaK# > 0.1), hot (>1400–1450°C), and damp mantle (>350–700 ppm water) sources. When garnet‐lherzolite melting does occur, the fraction of melting that takes place in the garnet field is not sufficient to impart a recognizable true garnet signature in the major and trace element composition of pooled melts except at ultraslow‐spreading rates (half rate ≤ 0.5 cm/yr). Therefore, for ambiguous garnet trace element signatures in MORB to be “true” would require that they are near‐fractional garnet‐lherzolite melts or garnet‐pyroxenite melts diluted by mixing in random proportions. While we do not test the process of random mixing, we find that near‐fractional and pooled melts of variable major and trace element mantle peridotite compositions at different mantle potential temperatures can explain the range of garnet signatures in MORB. For spinel‐peridotite melting to support garnet signatures requires mantle porosities ϕ = ∼0.1%; however, plagioclase‐peridotite melting, under specific circumstances, can explain MORB garnet signatures with ϕ = ∼1%.
P Wave Tomography Beneath Greenland and Surrounding Regions: 1. Crust and Upper Mantle
Authors: Toyokuni Genti , Matsuno Takaya , Zhao Dapeng
Published: October 2020

We study the 3‐D P wave velocity (Vp) structure of the crust and upper mantle beneath Greenland and surrounding regions using the latest P wave arrival time data. The Greenland Ice Sheet Monitoring Network (GLISN), initiated in 2009, is an international project for seismic observation in these regions using 34 stations. We use a regional seismic tomography method to simultaneously invert P wave arrival times of local earthquakes and P wave relative traveltime residuals of teleseismic events. These data are extracted from the ISC‐EHB catalog; however, for the teleseismic data, we picked new arrival times from seismograms using a cross‐correlation method. Our tomographic results clearly reveal the Iceland plume, the Jan Mayen plume, and a newly discovered “Svalbard plume,” which merge together in the mantle transition zone. A high‐Vp body exists beneath the Greenland Sea, which might act as an obstacle against the rising Svalbard plume. Furthermore, our results reveal a remarkable low‐Vp anomaly elongated in the NW‐SE direction at depths ≤250 km beneath central Greenland, which is connected with the Iceland and Jan Mayen hotspots. Although previous studies have suggested a similar feature, our result is the first to show the low‐Vp zone existing at all depths in the Greenland lithosphere, and its spatial distribution coincides with a high heat flux region. These characteristics indicate that the low‐Vp zone reflects residual heat from the Iceland plume when the Greenland lithosphere passed over this plume at ~80–20 Ma. Our results also indicate the possible existence of residual heat from the Jan Mayen plume.
Temporal Variations of the Marine Geoid
Authors: Siegismund F. , Köhl A. , Rummel R. , Stammer D.
Published: October 2020

The effects of temporal changes in the marine geoid on estimates of the ocean dynamic topography are being investigated. Influences from mass redistribution due to changes of land hydrology, ice sheets, glacial isostatic adjustment (GIA), and ocean and atmospheric dynamics are considered, and the associated crustal deformation is included. The strongest signals are associated with the seasonal cycle caused by changes in terrestrial water storage and ice sheets as well as the redistribution of atmospheric mass. Second to this is the importance of an overall trend caused by GIA and decreasing ice sheets over Greenland and Antarctica. On long spatial scales, the amplitude of regional trends estimated for the geoid height has a sizable fraction of those from sea level anomaly (SLA) for the period 1993–2016, also after subtraction of steric height of the upper 1,000 m to analyze trends in deep ocean geostrophic currents. The estimated strong negative geoid height trend south of Greenland for the period 1993–2016 opposes changes in dynamic sea level for the same period thereby affecting past studies on changes of both the strength of the subpolar gyre based on SLA and the meridional overturning circulation on a section between Cape Farewell and Portugal applying ocean dynamic topography and hydrography. We conclude that temporal geoid height trends should be considered in studies of (multi)decadal trends in sea level and circulation on large spatial scales based on altimetry data referenced to a geoid field.
Weak Response of Biological Productivity and Community Structure of Phytoplankton to Mesoscale Eddies in the Oligotrophic Philippine Sea
Authors: Yun Mi Sun , Kim Yejin , Jeong Yubeen , Joo Hui Tae , Jo Young‐Heon , Lee Chang Hwa , Bae Hyeonji , Lee Dabin , Bhavya P. S. , Kim Dongseon , Sun Jun , Lee Sang H.
Published: October 2020

In the Philippine Sea, mesoscale eddies have been frequently observed, but little is known about their contributions to the biological productivity and community structure of phytoplankton in the region. In situ carbon and nitrogen uptake rates and phytoplankton community structure were investigated in the Philippine Sea based on the 13C‐15N dual‐tracer technique and photosynthetic pigment analysis from late August to September 2018. Based on the comparison of the phytoplankton community structure among the cold eddy, warm eddy, and outer area, we found that the phytoplankton composition was different in the warm eddy with relatively lower contributions of large phytoplankton. However, a distinct enhancement in phytoplankton biomass over the euphotic zone was not detected even in eddy occurrence. In terms of community, the picoplankton Prochlorococcus was persistently dominant, which was attributed to a low supply and chemical composition of nutrients. The average integrated primary productions (IPP) were 80.4, 75.9, and 76.3 mg C m−2d−1 for the cold eddy, warm eddy, and outer area, respectively. The IPP under the eddy condition was not largely different from that in reference sites, even though the vertical distribution of productivity maximum was found to be different depending on eddy condition. These weak biological responses to mesoscale eddies might be attributed to the sustaining picoplankton‐dominant community structure and no substantial upward inputs of nutrients to the euphotic zone. Our findings represent an important contribution to understanding the biological response of mesoscale eddies in the oligotrophic Philippine Sea.
Inherent Optical Properties‐Reflectance Relationships Revisited
Authors: Lo Prejato Marilisa , McKee David , Mitchell Catherine
Published: October 2020

Understanding the relationship between remote sensing reflectance, Rrs(λ) and the inherent optical properties (IOPs) of natural waters is potentially a key to improving our ability to determine biogeochemical constituents from radiometric measurements. These relationships are usually described as a function of absorption, a(λ), and backscattering, bb(λ), coefficients, with the literature providing various forms of equation operating on either bb(λ)/a(λ) or bb(λ)/[a(λ)+bb(λ)] to represent the impact of variations in light field geometries and changes in sea‐water composition. The performance of several IOP‐reflectance relationships is assessed using HydroLight radiative transfer simulations covering a broad range of Case 1 and Case 2 water conditions. While early versions of IOP‐reflectance relationships assigned variability to associated proportionality factors (e.g., f/Q) or low‐order polynomial functions, recent studies have demonstrated relationships between Rrs(λ) and bb(λ)/[a(λ)+bb(λ)] are well‐characterized by nonlinear (high‐order polynomial), monotonic functions. This study demonstrates that this approach is also valid for relationships operating on bb(λ)/a(λ) and that there is no intrinsic benefit to functions operating on bb(λ)/[a(λ)+bb(λ)] compared to bb(λ)/a(λ) for Case 2 waters, contrary to recent suggestions in the literature. In all cases it is necessary to carefully consider the performance of best fit relationships across the full range of variability of IOPs and Rrs(λ), with higher order polynomials required to enable equivalent performance across the range of natural variability. The analysis further demonstrates insignificant wavelength sensitivity across the visible region, limited sensitivity to changes in solar zenith angle and extends to relationships for below surface remote sensing reflectance, rrs(λ).
Parameterizations of Entrainment‐Mixing Mechanisms and Their Effects on Cloud Droplet Spectral Width Based on Numerical Simulations
Authors: Luo Shi , Lu Chunsong , Liu Yangang , Bian Jianchun , Gao Wenhua , Li Junjun , Xu Xiaoqi , Gao Sinan , Yang Suying , Guo Xiaohao
Published: October 2020

Entrainment‐mixing mechanisms significantly affect cloud droplet number concentration, radius, and spectral shape. Quantitative examination of entrainment‐mixing effects on cloud droplet spectral width is lacking. This study examines the effects of entrainment‐mixing processes on cloud microphysics by 12,218 different setups, each simulated 10 times using the Explicit Mixing Parcel Model (EMPM) driven by the observational data from the Third Tibetan Plateau Atmospheric Scientific Experiment (TIPEX‐III) campaign. Parameterizations of entrainment‐mixing mechanisms are developed by relating homogeneous mixing degree to transition scale number that depends on the dissipation rate and droplet evaporation time scale. The correlation between relative dispersion of cloud droplet size distribution and homogeneous mixing degree changes from negative to positive with the decreasing homogeneous mixing degree. The different relationships are closely related to the competition between complete and partial droplet evaporation and the number concentration of small droplets, which are quantitatively described by two newly introduced dimensionless numbers. The competition is significantly affected by relative humidity and mixing fraction of entrained air as well as turbulence dissipation rate, but not much by cloud droplet number concentration. Especially, when relative humidity and dissipation rate are high, there is only a negative correlation. This study sheds new light on generalizing the homogeneous/inhomogeneous concept by considering relative dispersion and also provides parameterizations of entrainment‐mixing processes and relative dispersion for atmospheric models.
Identification of Sea Breeze Recirculation and Its Effects on Ozone in Houston, TX, During DISCOVER‐AQ 2013
Authors: Li Wei , Wang Yuxuan , Bernier Claudia , Estes Mark
Published: October 2020

In coastal environments, sea breeze recirculation has been found to be an important mesoscale meteorological phenomenon that causes high ozone episodes, yet the identification of this small‐scale circulation pattern remains difficult. In this study, a new method was developed to automatically identify sea breeze recirculation in Houston, TX, by applying K‐Means clustering algorithm to surface winds measurements at near‐coast sites during the DISCOVER‐AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaign period from August to October 2013. The key to the clustering algorithm is seven features derived from site‐based surface winds on each day, including zonal (U) and meridional (V) winds in the morning and afternoon, 24‐hr transport direction (θ) and the recirculation factor, which is the ratio of net transport distance (L) to wind run distance (S). For comparison, the same clustering was applied to San Antonio, TX, a noncoastal city yet within the synoptic‐scale distance from Houston. Four clusters were obtained for each region, including three synoptic patterns common to both regions and one mesoscale pattern that differs by region, classified as Stagnation and Sea Breeze Cluster for San Antonio and Houston, respectively. The clustering outputs were verified by wind profiler data in Houston. By linking the wind clusters with surface and aircraft ozone measurements, we revealed a clear connection between circulation patterns and daily ozone variability showing that maximum daily average 8‐hr (MDA8) ozone levels and spatial distributions differed by cluster type (e.g., the highest ozone found in the Stagnation/Sea Breeze Cluster and the lowest ozone in the Southerly Cluster). This automatable method of sea breeze identification we developed can be potentially applied to other coastal cities because it has low data requirement and no ad hoc location‐specific adjustments.
Impacts of Greenland Block Location on Clouds and Surface Energy Fluxes Over the Greenland Ice Sheet
Authors: Ward Jamie L. , Flanner Mark G. , Dunn‐Sigouin Etienne
Published: October 2020

Clouds and blocking activity have been implicated as causes of increased Greenland Ice Sheet (GrIS) melt in the 21st century. Although Greenland blocks (i.e., long‐lasting, mostly stationary anticyclones) generally reduce cloud cover and move warm air over Greenland, the elevated GrIS perturbs air and moisture transport in complex ways, implying a need to better understand how blocks affect cloud and surface energy flux anomaly patterns. In this study, we use a combination of daily MODIS cloud data and meteorological and energy flux data from MERRA‐2 reanalysis to better understand how Greenland block location, separated into four equal‐area quadrants, affects regional cloud and surface energy flux spatial patterns in the summer months of 2002–2018. Overall, cloud fraction and cloud water path reductions are approximately four times greater during northern block days than southern block days. Net cloud radiative forcing anomalies are negative for all Greenland block locations because negative longwave cloud radiative forcing anomalies exceed positive shortwave cloud radiative forcing changes. However, greater cloud cover reductions during northern block days produce more negative net cloud radiative forcing anomalies than southern block days. Greenland‐average (i.e., latitude‐weighted average of all GrIS grids) net surface energy flux anomalies range from +7 to +12W/m2 for all block quadrants. While net shortwave energy anomalies dominate the total surface energy response during western Greenland block days, sensible heating is responsible for approximately half of positive total surface energy change during eastern Greenland block days.
Atmospheric Water Vapor Budget and Its Long‐Term Trend Over the Tibetan Plateau
Authors: Yan Hongru , Huang Jianping , He Yongli , Liu Yuzhi , Wang Tianhe , Li Jiming
Published: October 2020

The rapid warming and consequent retreat of glaciers across the Tibetan Plateau (TP) have given rise to the debate on the ability of the atmospheric water supply to alleviate the depletion of surface water storage. We investigate long‐term changes in atmospheric water vapor balance across the TP using 40‐year fifth generation European Centre for Medium‐Range Weather Forecasts (ECMWF) (ERA5) reanalysis. Precipitation, water vapor convergence, and evaporation generally maintain an equilibrium but with different long‐term variation trends: 0.68, −0.18, and 0.69 mm/a, respectively. Results suggest the inability of the water vapor arriving from outside the TP to effectively replenish the surface water storage. Despite of huge changes in atmospheric water vapor balance during summer, the risk of water storage depletion is brought by other three seasons, especially the autumn. The climatology and long‐term trends of water vapor balance exhibit strong variation across the regions of TP. The surrounding areas of Yarlung Zangbo Grand Canyon experience sharp decrease in water vapor convergence, thus reducing precipitation. Moreover, increasing evaporation is expected to severely loss of surface water storage. For the Three Rivers Source Region with no significant changes in total precipitations, decrease in water transported from outside of TP overlaps increase in evaporation results in the possible depletion of surface water storage. Brahmaputra basin, inner TP, and Qilian Mountain exhibit significant wetting trends due to increases in both convergence of water vapor flux and evaporation. Above regional and seasonal characteristics of water vapor, balances across the TP are attributed by inhomogeneous variation of atmospheric heat source and complex changes of atmospheric circulations.
Analytical Investigation of the Reaction‐Diffusion Waves in the Mesopause Photochemistry
Authors: Kulikov M. Yu. , Belikovich M. V. , Feigin A. M.
Published: October 2020

The mechanism of the generation of reaction‐diffusion waves in the mesopause region (80–90 km) has been studied analytically. These waves are the propagating phase fronts arising in the oscillations of O, O3, H, OH, and HO2 concentrations. They appear in the presence of horizontal eddy diffusion in zonal direction when mesospheric photochemistry responds subharmonically (with a period of 2 days) to diurnal variations of solar radiation. The photochemical system in the mesopause region is a nonlinear oscillator which can be roughly described by a system of two differential nonautonomous equations with power law nonlinearity which was derived in our earlier papers. To model the wave propagation, we have considered a continuous chain of oscillators with diffusion coupling and with the phase of external periodic forcing depending linearly on spatial coordinates. It was found that the reaction‐diffusion waves are caused by specific “wind” type transport appearing in the equations for the amplitudes of 2‐day photochemical oscillations of O and H concentrations due to the zonal inhomogeneity of the external forcing. The obtained expression for the wave propagation velocity fully confirmed the earlier numerical results that the magnitude of the velocity is proportional to the diffusion coefficient and the gradient of the external forcing phase. The wave propagation direction is determined by the definite phase relations specified by internal parameters of the system only.
Using Factor Separation to Elucidate the Respective Contributions of Desert Dust and Urban Pollution to the 4 January 2020 Tel Aviv Lightning and Flash Flood Disaster
Authors: Lynn Barry H. , Yair Yoav , Shpund Jacob , Levi Yoav , Qie Xiushu , Khain Alexander
Published: October 2020

A numerical investigation was conducted to assess the possible impact of desert dust and urban aerosols on a very intense and deadly thunderstorm that occurred within the Tel Aviv metropolitan area on 4 January 2020. For these purposes, the cloud drop nucleation scheme within the spectral (bin) microphysics scheme (SBM) in the Weather Research and Forecasting Model (WRF) was coupled with the GoCart (desert) dust model and with hourly surface observations of urban aerosols. Using SBM integrated mass contents and simulated vertical velocities, the dynamic lightning scheme was able to forecast lightning rates within thunderclouds developing in an environment of marine or marine/continental aerosols with dust and/or urban aerosol forcings. Of these aerosol forcings (or factors), the urban aerosols (pollution) intensified lightning rates in convective clouds forming at and just off the Israeli coastline (referred to as the Urban Aerosol Lightning Enhancement Effect; ULE). The inclusion of continental aerosols with dust and urban aerosol sources resulted in the simulation exhibiting the most intense lightning and precipitation storm (referred to as Large Aerosol Small Aerosol Invigoration Effect; LASI). Yet, a comparison of model results and observations suggests that it was the combination of desert dust and urban aerosols alone that focused storm development over western Tel Aviv. The result was that high lightning rates initially focused over western Tel Aviv were accompanied by and then succeeded by a period of heavy rain that led to deadly flooding.
Modeling Hydro‐Morphodynamic Processes During the Propagation of Fluvial Sediment Pulses: A Physics‐Based Framework
Authors: Castro‐Bolinaga Celso F. , Diplas Panayiotis , Bodnar Robert J.
Published: October 2020

Fluvial sediment pulses are associated with a sudden and major increase in sediment supply to riverine environments. Their occurrence can be triggered by natural or anthropogenic factors or processes, including landslides, debris flows from tributaries, volcanic eruptions, dam removals, and mining‐related activities. To predict their propagation, decoupled (clear‐water) models are commonly used, despite shortcomings identified when simulating the initial propagation phase and the existence of coupled (sediment‐laden) models. Herein, a framework for improving the accuracy of modeling efforts that simulate fluvial sediment pulse propagation dynamics is presented. The framework is centered on a physics‐based criterion formed by a dimensionless parameter ξ and its threshold condition ξcr. Comparison with laboratory and field studies shows that ξ indicates the relative importance of the terms neglected in decoupled models and that its threshold condition ξcr effectively sets an upper limit for their application. Results show that decoupled models are inaccurate when ξ > ξcr but become sufficient when ξ < ξcr. When applied to well‐monitored fluvial sediment pulses, the framework quantifies the two‐phase propagation dynamics observed in the field, showing an initial phase characterized by ξ > ξcr and a subsequent phase characterized by ξ ≤ ξcr. Overall, the framework provides a physics‐based quantitative approach that addresses the limitations of decoupled models by setting an upper limit for their range of validity.
In Situ and Step‐Heating 40Ar/39Ar Dating of White Mica in Low‐Temperature Shear Zones (Tenda Massif, Alpine Corsica, France)
Authors: Beaudoin Alexandre , Scaillet Stéphane , Mora Nicolas , Jolivet Laurent , Augier Romain
Published: October 2020

In order to clarify the link between 40Ar/39Ar record in white mica and deformation, we performed in situ and bulkwise 40Ar/39Ar dating over the East Tenda Shear Zone (Tenda massif, Alpine Corsica). White micas from 11 samples were selected and extensively analyzed using in situ techniques across nested scales of strain‐intensity gradients developed at the expense of a late‐Variscan protolith. 40Ar/39Ar systematics are unaffected by inherited Ar and directly linked to deformation with little or no Ar lattice (volume) diffusion. Extensive sampling allows constraining the end of deformation related to burial and exhumation, respectively, at ~34 and ~22 Ma, bracketing the duration of regional extensional shear to ~12 Myr. Results also highlight a regional strain localization toward the upper contact of the unit with smaller‐scale localization in specific lithologies, notably meta‐aplites. Second‐order complications exist, such as local ill‐defined correlations between ages and finite‐strain microstructures. Thus, the use of a strain gradient as a proxy for strain localization in time is regionally valid but sometimes locally too complex to track or resolve strain partitioning/localization trends at the meter (outcrop) scale and below. Age mixing and incomplete isotopic homogenization by dissolution/precipitation are identified as the main causes of local discrepancies that complicate the link between age and microstructure and the derivation of strain localization rates. Tracking temporal trends in shear distribution across regional‐scale deformation gradients in such settings is possible but requires a multi‐scale approach as implemented here to reveal younging patterns associated to strain localization.
Yanshanian Orogeny During North China's Drifting Away From the Trench: Implications of Numerical Models
Authors: Yang Ting , Liu Shaofeng , Guo Peng , Leng Wei , Yang An
Published: October 2020

Tectonics in North China and adjacent areas were dominated by the Pacific Plate subduction since the Jurassic. Although the extension‐dominated tectonics in North China since the Early Cretaceous can be well explained by the Pacific Plate subduction, it is still not well understood why North China and adjacent areas underwent intense compression (Yanshanian orogeny) during the Late Jurassic and why these regions rapidly switched to extension‐dominated tectonics during the Early Cretaceous. Plate reconstructions suggest that East Asia was moving rapidly in the direction opposite the trench during the Jurassic when North China was undergoing strong compressional deformation. This relationship between back‐arc deformation and overriding plate's motion seems to contradict previous compilations and geodynamic models. We suggest that large‐scale mantle convection and exotic terrane accretions along the East Asian margin have jointly contributed to the Yanshanian orogeny across North China during the Jurassic. We verify this hypothesis with numerical geodynamic models. Our numerical experiments also suggest that large‐scale downwelling mantle flow beneath Asia has promoted continued subduction beneath the Asian margin despite the subduction was often punctuated by collisional and accretionary events.
Silencing long non-coding RNA CASC9 inhibits colorectal cancer cell proliferation by acting as a competing endogenous RNA of miR-576-5p to regulate AKT3
Authors: Liu Hui-Zi , Shan Ti-Dong , Han Yue , Liu Xi-Shuang
Published: October 2020

Increasing studies have shown that long non-coding RNAs (lncRNAs) are regarded as important regulators in the occurrence and development of colorectal cancer (CRC). Although lncRNA CASC9 has been studied in CRC, the detailed regulatory mechanism of CASC9 in CRC is still unclear. In this study, we found that CASC9 was significantly upregulated in CRC tissues and cell lines compared to normal controls and that aberrant expression was associated with the tumor-node-metastasis (TNM) stage of CRC. Functionally, CASC9 depletion efficiently inhibited the proliferation of CRC cells and induced cell apoptosis in vitro. Mechanistically, CASC9 was mainly enriched in the cytoplasm of CRC cells and interacted directly with miR-576-5p. Downregulation of miR-576-5p reversed the inhibitory effect of CASC9 siRNA on CRC cell progression. Furthermore, AKT3 has been identified as a downstream target of miR-576-5p. Spearman’s correlation analysis revealed that AKT3 was negatively correlated with miR-576-5p but positively correlated with CASC9. Downregulation of miR-576-5p restored the effect of CASC9 silencing on AKT3 expression. Therefore, silencing CASC9 could downregulate the expression of AKT3 by reducing the competitive binding of CASC9 to miR-576-5p, thus suppressing CRC cell proliferation and promoting cell apoptosis. In summary, we identified CASC9 as an oncogenic lncRNA in CRC and defined the CASC9/miR-576-5p/AKT3 axis, which might be considered a potential therapeutic target for CRC patients, as a novel molecular mechanism implicated in the proliferation and apoptosis of CRC.
Effects of the agility boot camp with cognitive challenge (ABC-C) exercise program for Parkinson’s disease
Authors: Jung Se Hee , Hasegawa Naoya , Mancini Martina , King Laurie A. , Carlson-Kuhta Patricia , Smulders Katrijn , Peterson Daniel S. , Barlow Nancy , Harker Graham , Morris Rosie , Lapidus Jodi , Nutt John G. , Horak Fay B.
Published: November 2020

Few exercise interventions practice both gait and balance tasks with cognitive tasks to improve functional mobility in people with PD. We aimed to investigate whether the Agility Boot Camp with Cognitive Challenge (ABC-C), that simultaneously targets both mobility and cognitive function, improves dynamic balance and dual-task gait in individuals with Parkinson’s disease (PD). We used a cross-over, single-blind, randomized controlled trial to determine efficacy of the exercise intervention. Eighty-six people with idiopathic PD were randomized into either an exercise (ABC-C)-first or an active, placebo, education-first intervention and then crossed over to the other intervention. Both interventions were carried out in small groups led by a certified exercise trainer (90-min sessions, 3 times a week, for 6 weeks). Outcome measures were assessed Off levodopa at baseline and after the first and second interventions. A linear mixed-effects model tested the treatment effects on the Mini-BESTest for balance, dual-task cost on gait speed, SCOPA-COG, the UPDRS Parts II and III and the PDQ-39. Although no significant treatment effects were observed for the Mini-BESTest, SCOPA-COG or MDS-UPDRS Part III, the ABC-C intervention significantly improved the following outcomes: anticipatory postural adjustment sub-score of the Mini-BESTest (p = 0.004), dual-task cost on gait speed (p = 0.001), MDS-UPDRS Part II score (p = 0.01), PIGD sub-score of MDS-UPDRS Part III (p = 0.02), and the activities of daily living domain of the PDQ-39 (p = 0.003). Participants with more severe motor impairment or more severe cognitive dysfunction improved their total Mini-BESTest scores after exercise. The ABC-C exercise intervention can improve specific balance deficits, cognitive-gait interference, and perceived functional independence and quality of life, especially in participants with more severe PD, but a longer period of intervention may be required to improve global cognitive and motor function.
Application of a new adhesive elastomeric coating and hydrophilic–lipophilic-balanced sorbent for modified stir-bar sorptive extraction
Authors: Teixeira Natascha A. , Miyazaki Duanne M. S. , Grassi Marco T. , Zawadzki Sônia F. , Abate Gilberto
Published: October 2020

A new adhesive was employed to fix HLB sorbent in stir-bars, providing high chemical/mechanical resistance and appropriate performance.
An ROS-sensitive tegafur-PpIX-heterodimer-loaded in situ injectable thermosensitive hydrogel for photodynamic therapy combined with chemotherapy to enhance the tegafur-based treatment of breast cancer
Authors: Zhang Zhiqiang , Li Anning , Min Xingqi , Zhang Qunqun , Yang Jun , Chen Guo , Zou Meijuan , Sun Wei , Cheng Gang
Published: October 2020

A temperature-sensitive hydrogel encapsulating tegafur and protoporphyrin IX dimers could be delivered intratumorally for synergetic chemotherapy and photodynamic therapy.
Boosting the electrocatalysis of nitrate to nitrogen with iron nanoparticles embedded in carbon microspheres
Authors: Hong Wen , Su Li , Wang Jiancheng , Jiang Min , Ma Yuanyuan , Yang Jianping
Published: October 2020

Iron nanoparticles embedded in carbon microspheres (Fe@C) are facilely designed with excellent electrocatalytic denitrification performance.
Magnetism modulation and conductance quantization in a gadolinium oxide memristor
Authors: Xie Zhuolin , Gao Shuang , Ye Xiaoyu , Yang Huali , Gong Guodong , Lu Ying , Ye Junya , Liu Gang , Li Run-Wei
Published: October 2020

Magnetism modulation and conductance quantization are realized simultaneously in a single Gd2O3 memristor, which offers a powerful platform for the construction of multifunctional electronic and spintronic devices in the future.
Enhanced magnetic anisotropy and Curie temperature of the NiI2 monolayer by applying strain: a first-principles study
Authors: Han Hecheng , Zheng Huiling , Wang Qiushi , Yan Yu
Published: October 2020

Two-dimensional (2D) intrinsic ferromagnetic semiconductors with high magnetic anisotropy (MA) and Curie temperature (TC) are desirable for low-dimensional spintronic applications.
Electronic and geometrical parametrization of the role of organic/inorganic cations on the photovoltaic perovskite band gap
Authors: Kanani Mansour , Moaddeli Mohammad
Published: October 2020

Parameterizing the role of organic/inorganic A site cations on the perovskite band gap, to build a systematic bottom-up approach for comparing various A site cation candidates.
Rational design of a functionalized aluminum metal–organic framework as a turn-off fluorescence sensor for α-ketoglutaric acid
Authors: Das Aniruddha , Alam Masud , Gogoi Chiranjib , Dalapati Rana , Biswas Shyam
Published: October 2020

A hydrazinyl functionalized DUT-5 MOF is reported for the rapid and selective detection of α-ketoglutaric acid (α-KG).
Extreme condition high temperature and high pressure studies of the K–U–Mo–O system
Authors: Murphy Gabriel L. , Kegler Philip , Klinkenberg Martina , Wang Shuao , Alekseev Evgeny V.
Published: October 2020

The first examples of alkali earth uranyl molybdates synthesised using high temperature and high pressure methods, K2[UO2(Mo2O7)2], K2[(UO2)2(Mo(vi)4Mo(iv)(OH)2)O16], K3[(UO2)6(OH)2(MoO4)6(MoO3OH)] and K5[(UO2)10MoO5O11OH]·H2O, are described and characterized.
Facile cyclization of sodium aminodiboranate to construct a boron–nitrogen–hydrogen ring
Authors: Li Huizhen , Ju Mingyue , Kang Jiaxin , Zhou Ai-Ju , Guan Hong-Yu , Austin Douglas J. , Yue Yanfeng
Published: October 2020

One-step cyclization of aminodiboranate can be used to prepare aminodiborane efficiently, where the dihydrogen bond plays an important role.
Experimental and theoretical studies of the ternary thiophosphate PbPS3 featuring ethane-like [P2S6]4− units
Authors: Wang Peng , Abudoureheman Maierhaba , Chen Zhaohui
Published: October 2020

PbPS3 with isolated ethane-like [P2S6]4− units exhibits good optical properties and shows promising application as a birefringent material.
Tuning the spin polarization in monolayer MoS2 through (Y,Yb) co-doping
Authors: Niu Yong , Wang Pan , Zhang Mingzhe
Published: October 2020

Yb-Doped monolayer MoS2 is ferromagnetic at room temperature, and this ferromagnetic state can be stabilized by Y co-doping.
Broadband polarization-insensitive and wide-angle solar energy absorber based on tungsten ring-disc array
Authors: Yi Zao , Li Jiakun , Lin Jiangchuan , Qin Feng , Chen Xifang , Yao Weitang , Liu Zhimin , Cheng Shubo , Wu Pinghui , Li Hailiang
Published: October 2020

We find that the solar energy absorption efficiency is high under a solar spectrum at AM 1.5, and it also has polarization-independence and incidence insensitivity. Our absorber has the widest operating band compared with similar absorbers reported previously.
An aerobic and green C–H cyanation of terminal alkynes
Authors: Zhu Peng-Fei , Si Yi-Xin , Zhang Song-Lin
Published: October 2020

This study reports the C–H cyanation of terminal alkynes with α-cyanoacetates serving as a readily available and friendly cyano source under Cu/O2 conditions.
Single-atom Ru anchored in nitrogen-doped MXene (Ti3C2Tx) as an efficient catalyst for the hydrogen evolution reaction at all pH values
Authors: Liu Haigang , Hu Zhe , Liu Qinglei , Sun Peng , Wang Yongfei , Chou Shulei , Hu Zhizhi , Zhang Zhiqiang
Published: October 2020

A catalyst consisting of single-atom Ru sites supported on an N-MXene (Ti3C2Tx) was developed for pH-universal hydrogen generation based on theoretical predictions, whose performances are comparable to and better than those of Pt/C.
Target-directed enzyme-free dual-amplification DNA circuit for rapid signal amplification
Authors: Xing Chao , Chen Ziyi , Zhang Cheng , Wang Jun , Lu Chunhua
Published: October 2020

An enzyme-free, single-step and rapid signal amplification DNA circuit was developed by integrating target-directed entropy-driven catalysis and hybridization chain reaction for fluorescence analysis of nucleic acids and small molecules.
New developments in Huntington’s disease and other triplet repeat diseases: DNA repair turns to the dark side
Authors: Lahue Robert S.
Published: November 2020

Huntington’s disease (HD) is a fatal, inherited neurodegenerative disease that causes neuronal death, particularly in medium spiny neurons. HD leads to serious and progressive motor, cognitive and psychiatric symptoms. Its genetic basis is an expansion of the CAG triplet repeat in the HTT gene, leading to extra glutamines in the huntingtin protein. HD is one of nine genetic diseases in this polyglutamine (polyQ) category, that also includes a number of inherited spinocerebellar ataxias (SCAs). Traditionally it has been assumed that HD age of onset and disease progression were solely the outcome of age-dependent exposure of neurons to toxic effects of the inherited mutant huntingtin protein. However, recent genome-wide association studies (GWAS) have revealed significant effects of genetic variants outside of HTT. Surprisingly, these variants turn out to be mostly in genes encoding DNA repair factors, suggesting that at least some disease modulation occurs at the level of the HTT DNA itself. These DNA repair proteins are known from model systems to promote ongoing somatic CAG repeat expansions in tissues affected by HD. Thus, for triplet repeats, some DNA repair proteins seem to abandon their normal genoprotective roles and, instead, drive expansions and accelerate disease. One attractive hypothesis—still to be proven rigorously—is that somatic HTT expansions augment the disease burden of the inherited allele. If so, therapeutic approaches that lower levels of huntingtin protein may need blending with additional therapies that reduce levels of somatic CAG repeat expansions to achieve maximal effect.
DIBR‐synthesised video quality assessment by measuring geometric distortion and spatiotemporal inconsistency
Authors: Huang Yipo , Zhou Yu , Hu Bo , Tian Shishun , Yan Jiebin
Published: October 2020

Depth‐image‐based rendering (DIBR), as the most popular view synthesis method, is commonly used in the application of multi‐view and free‐viewpoint videos. However, the quality evaluation of DIBR‐synthesised videos remains largely unexplored, which may hinder the development of more advanced view synthesis technology. With this motivation, this Letter presents a new quality metric for DIBR‐synthesised videos. Specifically, the disoccluded regions are first detected based on an adaptive threshold to quantify geometric distortions. An energy‐based sequence mapping strategy is proposed to portray spatiotemporal inconsistency by calculating first‐order and second‐order similarities in the gradient magnitude domain and the Laplace‐of‐Gaussian domain, respectively. Finally, the overall quality score is generated by pooling the scores of geometric distortion and spatiotemporal inconsistency. Experimental results demonstrate that the proposed metric outperforms the state‐of‐the‐art metrics dedicated to DIBR‐synthesised images and videos.
Optimal transceiver design for energy harvesting two‐way relay networks
Authors: Jiang Xue , Zheng Baoyu , Zhu Wei‐Ping , Wang Lei , Zou Yulong
Published: October 2020

Simultaneous wireless information and power transfer (SWIPT) is a promising solution for future wireless networks as it provides convenient and perpetual energy supplies to wireless users. This study proposes three new transceiver design schemes in two‐way relay networks with SWIPT. Firstly, a transmit power minimisation solution is proposed with an aim to minimise the transmit power while meeting an energy harvesting requirement. Then, a harvested energy maximisation solution that has the same complexity as the first solution but provides a much better sum harvested energy is proposed. Finally, a signal‐to‐interference‐plus‐noise ratio maximisation solution is developed, which gives the best sum‐rate performance for the two‐way relay networks while ensuring a desired level of energy harvesting. Furthermore, the complexity of the three new transceiver solutions is discussed. Simulation results have demonstrated the effectiveness of the proposed transceiver design schemes in two‐way relay networks with SWIPT.
Metallic and dielectric hybrid 3D printed K‐band dielectric‐loaded antenna with reduced sidelobe
Authors: Zhang Bing , Zhou Lin , Chen Qian , Wu Li , Zhou Yanping , Zhu Huacheng , Zhang Yi , Cheng Fei , Lu Ping , Huang Kama , Yang Yang
Published: October 2020

A K‐band (18–27 GHz) dielectric‐loaded waveguide antenna is designed as the feed for a parabolic reflector. The antenna is composed of a waveguide launcher and a dielectric load. The waveguide launcher is fabricated by selective laser melting using aluminium alloy. The dielectric load is fabricated by stereolithography using resin. The aperture field distribution of the antenna is tuned by extending the E‐ and H‐walls of the waveguide launcher to radiate a sidelobe‐reduced main beam in the boresight from −90° to  + 90°. The agreement is achieved between the simulation and measurement. It has impedance bandwidth of |S11|<−10 from 18 to 27 GHz, the maximum gain of 11.8 dBi @ 19 GHz, and 3‐dB gain bandwidth from 18 to 25 GHz. For the sidelobe reduced, simple design and low cost, the proposed antenna features a good candidate as the feed for a parabolic reflector.
60 GHz wide‐band psi (Ψ)‐shaped long‐wire antenna for wireless on‐board chip‐to‐multi‐chip communication
Authors: Jang Tae Hwan , Park Chul Soon
Published: October 2020

A novel type of wide‐band long‐wire antenna is presented for 60 GHz wireless on‐board chip‐to‐multi‐chip applications using a vertically polarised electric field. The psi‐shaped structure is devised to match the antenna input impedance to 50 Ω and to increase the front‐to‐back ratio by placing two bent 0.5λeff lines parallel to the original long‐wire antenna, which resulted in improved realised gain and can be directivity compared to those of a conventional baseline structure. The psi‐shaped long‐wire antenna shows a peak gain of 10.2 dBi, an end‐fire gain of 7 dBi, a 22% impedance bandwidth (52–65.2 GHz), and a 25.8% 3 dB gain bandwidth (56–74 GHz) in an area of 3.1 × 105 mm2. This study presents the proposed antenna for an on‐board chip‐to‐multi‐chip communication scenario for a distance of 20 mm, with a peak transmission gain of −19.5 dB and a 3 dB bandwidth of 11.8 GHz (=19.6%), which ranges from 55.4 to 67.2 GHz.
Extended view on the dust shells around two carbon stars
Authors: Mečina M. , Aringer B. , Nowotny W. , Groenewegen M. A. T. , Kerschbaum F. , Brunner M. , Gail H.-P.
Published: October 2020

Context. Stars on the asymptotic giant branch lose considerable amounts of matter through their dust-driven stellar winds. A number of such sources have been imaged by Herschel/PACS, revealing a diverse sample of different morphological types. Among them are a few examples which show geometrically thin, spherically symmetric shells which can be used to probe the mass loss history of their host stars.

Aims. We aim to determine the physical properties of the dust envelope around the two carbon stars U Hya and W Ori. With the much-improved spatial constraints from the new far-infrared maps, our primary goal is to measure the dust masses contained in the shells and see how they fit the proposed scenarios of shell formation.

Methods. We calculated the radiative transfer of the circumstellar dust envelope using the 1D code More of DUSTY (MoD). Adopting a parametrised density profile, we obtained a best-fit model in terms of the photometric and spectroscopic data, as well as a radial intensity profile based on Herschel/PACS data. For the case of U Hya, we also computed a grid of circumstellar envelopes by means of a stationary wind code and compare the results of the two modelling approaches.

Results. The Herschel/PACS maps show U Hya surrounded by a detached shell of 114′′ (0.12 pc) in radius, confirming the observations from previous space missions. The dust masses calculated for the shell by the two approaches are consistent with respect to the adopted dust grain properties. In addition, around W Ori, we detect for the first time a weak spherically symmetric structure with a radius of 92′′ (0.17 pc) and a dust mass of (3.5 ± 0.3) × 10−6 M⊙.
Le concept de démantèlement sensoriel dans l’autisme et la démarche scientifique
Authors: Barrer Laurence
Published: November 2020

L’objectif de l’article est de mettre en évidence la possible utilisation de la démarche scientifique (Bernard, 1865) pour quantifier un mécanisme psychique décrit par la psychanalyse. Le mécanisme de défense du moi dans l’autisme appelé démantèlement sensoriel y est pris comme exemple de recherche. À partir des travaux de D. Meltzer (1972, 1975, 1986) l’auteur a appliqué un protocole de méthodes mixtes, qualitative (phénoménologique) et quantitative (statistiques) pour le mettre en évidence chez l’enfant autiste en psychothérapie d’inspiration psychanalytique. La méthode qualitative est étayée sur une méthodologie où la description de critères de preuve sous-tend l’observation à partir de 43 vidéos de séance sur 127. Les résultats de cette recherche montrent que le processus de démantèlement est un mécanisme de défense du Moi observable et quantifiable signant l’évolution de l’intersubjectivité de l’enfant autiste avec le thérapeute.