bluuebunny/crossref_metadata_2025 huggingface dataset:
Volume and surface effects on two-photonic and three-photonic processes in dry co-doped upconversion nanocrystals
Authors: Grauel Bettina , Würth Christian , Homann Christian , Krukewitt Lisa , Andresen Elina , Roik Janina , Recknagel Sebastian , Haase Markus , Resch-Genger Ute
Published: August 2021

Despite considerable advances in synthesizing high-quality core/shell upconversion (UC) nanocrystals (NC; UCNC) and UCNC photophysics, the application of near-infrared (NIR)-excitable lanthanide-doped UCNC in the life and material sciences is still hampered by the relatively low upconversion luminescence (UCL) of UCNC of small size or thin protecting shell. To obtain deeper insights into energy transfer and surface quenching processes involving Yb3+ and Er3+ ions, we examined energy loss processes in differently sized solid core NaYF4 nanocrystals doped with either Yb3+ (YbNC; 20% Yb3+) or Er3+ (ErNC; 2% Er3+) and co-doped with Yb3+ and Er3+ (YbErNC; 20% Yb3+ and 2% Er3+) without a surface protection shell and coated with a thin and a thick NaYF4 shell in comparison to single and co-doped bulk materials. Luminescence studies at 375 nm excitation demonstrate back-energy transfer (BET) from the 4G11/2 state of Er3+ to the 2F5/2 state of Yb3+, through which the red Er3+4F9/2 state is efficiently populated. Excitation power density (P)-dependent steady state and time-resolved photoluminescence measurements at different excitation and emission wavelengths enable to separate surface-related and volume-related effects for two-photonic and three-photonic processes involved in UCL and indicate a different influence of surface passivation on the green and red Er3+ emission. The intensity and lifetime of the latter respond particularly to an increase in volume of the active UCNC core. We provide a three-dimensional random walk model to describe these effects that can be used in the future to predict the UCL behavior of UCNC.
Formal design and verification of system task in intelligent transportation systems based on micro-kernel architecture
Authors: Qian Zhenjiang , Jin Yong , Sun Gaofei , Xing Xiaoshuang , Xia Kaijian
Published: August 2021

The accuracy of design and implementation of an operating system in intelligent transportation systems is difficult to describe and validate because of its complexity. In this paper, we describe an OS in intelligent transportation systems with automaton theory and establish an OS state model. Based on this model, we construct an isomorphic model in Isabelle/HOL, describe the work objects and operational semantics of the system, and verify the system at the assembly level. We use a micro-kernel OS prototype (VSOS) for intelligent transportation systems as an example to illustrate our method and verify the correctness of design and implementation in VSOS with Isabelle/HOL. Verification shows that the proposed method is feasible.
Verification of a chamberless HLFC design with an outer skin of variable porosity
Authors: Kilian T. , Horn M.
Published: August 2021

A chamberless HLFC leading edge segment featuring an outer skin with variable porosity has been designed, manufactured and wind tunnel tested under flight Reynolds-number conditions. The aerodynamic design involved the extention of current HLFC design routines to variable pressure loss characteristics of the outer skin. Advanced options for structural design and manufacturing solutions with focus on industrialization, arising from the avoidance of aerodynamically driven chambering, are explored. The leading edge segment has been installed on an existing vertical tail-plane model and tested at the large low-speed wind-tunnel facility DNW-LLF. The design process and some results of the successful verification of the chamberless design are presented herein.
Certain results on invariant submanifolds of an almost Kenmotsu $$(\kappa ,\mu ,\nu )$$-space
Authors: Atc̣eken Mehmet
Published: August 2021

In the present paper, we study invariant submanifolds of almost Kenmotsu structures whose Riemannian curvature tensor has $$(\kappa ,\mu ,\nu )$$

(
κ
,
μ
,
ν
)

-nullity distribution. Since the geometry of an invariant submanifold inherits almost all properties of the ambient manifold, we research how the functions $$\kappa ,\mu $$

κ
,
μ

and $$\nu $$
ν
behave on the submanifold. In this connection, necessary and sufficient conditions are investigated for an invariant submanifold of an almost Kenmotsu $$(\kappa ,\mu ,\nu )$$

(
κ
,
μ
,
ν
)

-space to be totally geodesic under some conditions.
Vector analysis of electric-field-induced antiparallel magnetic domain evolution in ferromagnetic/ferroelectric heterostructures
Authors: Zhao Xinger , Hu Zhongqiang , Wu Jingen , Fang Ting , Li Yaojin , Cheng Yuxin , Zhao Yifan , Guan Mengmeng , Xian Dan , Wang Chenying , Mao Qi , Peng Bin , Peng Ren-Ci , Zhou Ziyao , Wang Zhiguang , Jiang Zhuang-De , Liu Ming
Published: August 2021

Electric field (E-field) control of magnetism based on magnetoelectric coupling is one of the promising approaches for manipulating the magnetization with low power consumption. The evolution of magnetic domains under in-situ E-fields is significant for the practical applications in integrated micro/nano devices. Here, we report the vector analysis of the E-field-driven antiparallel magnetic domain evolution in FeCoSiB/PMN-PT(011) multiferroic heterostructures via in-situ quantitative magneto-optical Kerr microscope. It is demonstrated that the magnetic domains can be switched to both the 0° and 180° easy directions at the same time by E-fields, resulting in antiparallel magnetization distribution in ferromagnetic/ferroelectric heterostructures. This antiparallel magnetic domain evolution is attributed to energy minimization with the uniaxial strains by E-fields which can induce the rotation of domains no more than 90°. Moreover, domains can be driven along only one or both easy axis directions by reasonably selecting the initial magnetic domain distribution. The vector analysis of magnetic domain evolution can provide visual insights into the strain-mediated magnetoelectric effect, and promote the fundamental understanding of electrical regulation of magnetism.
Dyads, triads, and tetrads: a multivariate simulation approach to uncovering network motifs in social graphs
Authors: Felmlee Diane , McMillan Cassie , Whitaker Roger
Published: August 2021

Motifs represent local subgraphs that are overrepresented in networks. Several disciplines document multiple instances in which motifs appear in graphs and provide insight into the structure and processes of these networks. In the current paper, we focus on social networks and examine the prevalence of dyad, triad, and symmetric tetrad motifs among 24 networks that represent six types of social interactions: friendship, legislative co-sponsorship, Twitter messages, advice seeking, email communication, and terrorist collusion. Given that the correct control distribution for detecting motifs is a matter of continuous debate, we propose a novel approach that compares the local patterns of observed networks to random graphs simulated from exponential random graph models. Our proposed technique can produce conditional distributions that control for multiple, lower-level structural patterns simultaneously. We find evidence for five motifs using our approach, including the reciprocated dyad, three triads, and one symmetric tetrad. Results highlight the importance of mutuality, hierarchy, and clustering across multiple social interactions, and provide evidence of “structural signatures” within different genres of graph. Similarities also emerge between our findings and those in other disciplines, such as the preponderance of transitive triads.
Utility of TPP-manufactured biophysical restrictions to probe multiscale cellular dynamics
Authors: Fei Panyu , Ding Haibo , Duan Yu , Wang Xinyi , Hu Wei , Wu Peng , Wei Mengxiao , Peng Zhengchun , Gu Zhongze , Chen Wei
Published: August 2021

Biophysical restrictions regulate protein diffusion, nucleus deformation, and cell migration, which are all universal and important processes for cells to perform their biological functions. However, current technologies addressing these multiscale questions are extremely limited. Herein, through two-photon polymerization (TPP), we present the precise, low-cost, and multiscale microstructures (micro-fences) as a versatile investigating platform. With nanometer-scale printing resolution and multiscale scanning capacity, TPP is capable of generating micro-fences with sizes of 0.5–1000 μm. These micro-fences are utilized as biophysical restrictions to determine the fluidity of supported lipid bilayers (SLB), to investigate the restricted diffusion of Src family kinase protein Lck on SLB, and also to reveal the mechanical bending of cell nucleus and T cell climbing ability. Taken together, the proposed versatile and low-cost micro-fences have great potential in probing the restricted dynamics of molecules, organelles, and cells to understand the basics of physical biology.

Graphic abstract
Are acetic acid derivatives really negative to the iodoform test?
Authors: Nagata Daiki , Nishiwaki Nagatoshi
Published: August 2021

Acetic acid derivatives such as ethyl acetate have been considered to be negative to the iodoform test because of the predominant hydrolysis leading to acetic acid. We clarified the immiscible property of the ester was the actual reason for the negative result. When THF or 1-propanol was used as a solvent, even alkyl acetate underwent the iodoform reaction; however, it cannot be used as qualitative test because of high solubility of iodoform into these solvents. This problem was overcome by conducting the test in methanol. Indeed, not only alkyl acetates but also N,N-dimethylacetamide showed positive to the iodoform test producing a yellow precipitates.
Performance decline in a low‐stakes test at age 15 and educational attainment at age 25: Cross‐country longitudinal evidence
Authors: Borgonovi F. , Ferrara A. , Piacentini M.
Published: August 2021

Introduction

Educational attainment is associated with important life outcomes including labour market performance, health status, well‐being, civic and political participation. An important question is whether it is possible to identify early those students who lack the achievement motivation that is needed to complete a higher education degree.

Methods

Longitudinal follow‐ups of representative samples of participants in the 2000 and 2003 Programme for International Student Assessment (PISA) from Australia, Denmark and Switzerland (N = 3110; 1130; and 1962; age = 15 to 27; % females 51%, 51%, 49%; ethnicity/race unknown) were used to identify the association between a measure of effort on a cognitively demanding low‐stake task at age 15 – performance decline during the test – and educational attainment at age 25–27.

Results

A one SD difference in performance decline was associated with a 5–6 percentage point difference in the probability of obtaining tertiary‐level qualifications (r = −0.15 in Australia; −0.11 in Denmark and −0.11 in Switzerland). We find no evidence of differences in this relationship across genders, socio‐economic status and baseline levels of ability in the three countries. The association between performance decline and educational attainment is homogeneous across these groups. Self‐reported measures of achievement motivation were not predictive of educational attainment in the three countries.

Conclusions

Our work contributes new longitudinal evidence to the body of research in education employing behavioural measures of motivation and engagement. It can be used to understand the potential long‐term consequences of disparities in students' preparation to sustain effort over cognitively demanding tasks.
Application of XRF Scanning to Different Geological Archives
Authors: Guo Fei , Clemens Steven , Liu Xingxing , Long Yili , Li Dong , Tan Liangcheng , Liu Chengcheng , Yan Hong , Sun Youbin
Published: August 2021

High‐resolution XRF scanning is widely used on marine and lake sediment cores as a means of rapidly acquiring elemental concentrations from closely spaced intervals with no damage to the samples. Therefore, guidance on how to obtain reliable datasets and select suitable step sizes for different geological media are of great importance. Here we apply this efficient analytical method to loess, stalagmite, and tridacna samples. The results show that 11 elements (Al, Si, K, Ca, Ti, Mn, Fe, Rb, Sr, Zr, and Ba), eight elements (Ca, Si, K, Fe, Cu, Ni, Sc, and Sr) and seven elements (Ca, Sr, Cu, Fe, Sc, Ni, and Si) can be robustly detected by this method for loess, stalagmite and tridacna archives respectively, demonstrating the capacity to reconstruct high‐resolution paleoclimate changes. For loess cores, efficiency emission decay of the X‐ray tube, water content, matrix, and grain size effects are the main factors influencing elemental intensities. The efficiency emission decay of the X‐ray tube, scanning path, scanning interval, and radiation area have a significant effect on element intensities of stalagmite and tridacna samples. Based on our investigations, we suggest optimal resolutions for scanning these three archives for millennial to seasonal‐scale paleoclimatic reconstructions. We compare our analyses with existing results from traditional (discrete) analyses, demonstrating similar scales of variability. Our results suggest that geochemical proxies measured by XRF scanning, such as Rb/Sr, Zr/Rb, and Ca/Ti ratios of loess and the Sr/Ca ratio of speleothem and tridacna, can be effectively used to reconstruct high‐resolution paleoclimate changes.
Cellulose Oxygen Isotopes of Sphagnum and Vascular Plants in a Peat Core Reveal Climate Change in Northern Japan Over the Past 2,000 Years
Authors: Sakurai Hiromichi , Yamamoto Masanobu , Seki Osamu , Omori Takayuki , Sato Tomonori
Published: August 2021

The cellulose δ18O of plant tissues in peat is a potential climate proxy. However, understanding what is driving the shifts in δ18O of cellulose is required for its application. Here, we analyzed the δ18O values of Sphagnum and vascular plant cellulose, as well as the δ18O and δD values of pore water, in a 4‐m‐long peat core from the Bekanbeushi ombrotrophic bog to understand paleoclimatic changes in northern Japan over the past 2,000 years. The cellulose δ18O values of Sphagnum were lower than those of vascular plant tissues, although both draw water from the same layer. Whereas the cellulose δ18O values of Sphagnum more directly reflect those of precipitation, those of vascular plants become enriched through transpiration. Thus, the difference between vascular plants and Sphagnum (Δδ18Ovp–sp) is a potential proxy for relative humidity. Cellulose δ18O of Sphagnum revealed centennial variations with maxima around 800, 1300, and 1500 CE and minima around 500, 1000, 1700, and 1900 CE. The Δδ18Ovp–sp was inversely correlated with Sphagnum cellulose δ18O, indicating that the axis of summer westerlies was more frequently located to the north and the climate was moist in the former periods, whereas the axis of summer westerlies was generally located to the south and the climate was dry in the latter periods. These results suggest a warm and moist climate during the former periods due to frequent rainy summers driven by strong East Asian summer monsoon activity, and the opposite conditions in the latter periods.
Toward a Physics Based Model of Hypervelocity Dust Impacts
Authors: Kellogg Paul J. , Bale S. D. , Goetz Keith , Monson Steven J.
Published: August 2021

There has been important understanding of the process by which a hypersonic dust impact makes an electrical signal on a spacecraft sensor, leading to a fuller understanding of the physics. Zaslavsky (2015), https://doi.org/10.1002/2014ja020635 showed that the most important signal comes from the charging of the spacecraft, less from charging of an antenna. The present work is an extension of the work of Zaslavsky. An analytical treatment of the physics of a hypersonic dust impact and the mechanism for generating an electrical signal in a sensor, an antenna, is presented. The treatment is compared with observations from STEREO and Parker Solar Probe. A full treatment of this process by simulations seems beyond present computer capabilities, but some parts of the treatment must depend on simulations but other features can be better understood through analytical treatment. Evidence for a somewhat larger contribution from the antenna part of the signal than in previous publications is presented. Importance of electrostatic forces in forming the exiting plasma cloud is emphasized. Electrostatic forces lead to a rapid expansion of the escaping cloud, so that it expands more rapidly than it escapes, and sometimes surrounds one or more antennas. This accounts for the ability of dipole antennas to detect dust impacts. Some progress toward understanding occasional negative charging of an antenna is presented, together with direct evidence of such charging. Use of laboratory measurements of charge to estimate size of spacecraft impacts are shown to be not reliable without further calibration work.
Impact of Stratospheric Intrusions on Ozone Enhancement in the Lower Troposphere and Implication to Air Quality in Hong Kong and Other South China Regions
Authors: Zhao Kaihui , Huang Jianping , Wu Yonghua , Yuan Zibing , Wang Yongwei , Li Ying , Ma Xiaodan , Liu Xuehui , Ma Wei , Wang Ying , Zhang Xiaoyan
Published: August 2021

Stratospheric intrusions are an important source of ozone (O3) in the troposphere. In this study, 17 years of O3 sounding data from the Hong Kong Observatory with a weekly sampling frequency are analyzed to identify stratospheric intrusions and quantify their impact on O3 enhancement events in springtime from 2004 to 2020. 24.7% of O3 enhancement events are related to stratospheric intrusion whereas 31.7% of intrusions lead to the enhancement of O3 in the lower troposphere. Occurrences of stratospheric intrusion in springtime are closely related to tropopause folding and tropospheric convective activities in subtropical regions. The Weather Research and Forecasting model coupled with Chemistry simulations are conducted with the integrated process analysis to quantify the impact of stratospheric intrusions on the enhancement of O3 in the lower free troposphere as well as near the surface under different synoptic patterns. Synoptic patterns associated with stratospheric intrusion‐driving O3 enhancements are classified into two categories: Saddle Point (“S”) and Cold Front (“F”). While downward transport of O3‐enriched air from the enhancement layer exerts an important impact on surface O3 for synoptic pattern “S,” the impact on surface O3 is limited for surface pattern “F.” The impact of stratospheric intrusions together with entrainment on surface O3 may have a strong indication on the development of effective emission control strategies on surface O3 reduction in Hong Kong.
Vertical Biogeography and Realized Niche Traits of Living Coccolithophore Community in the Eastern Indian Ocean
Authors: Liu Haijiao , Wang Dongxiao , Yun Misun , Zhang Xiaodong , Zhang Guicheng , Thangaraj Satheeswaran , Sun Jun
Published: August 2021

Coccolithophores are crucial components of marine calcifying microalgae and found to be important indicators of ecological changes. The interannual scale and vertical biogeography of springtime living coccolithophore communities were determined in the chronically under‐sampled eastern Indian Ocean (EIO) during seven consecutive years (spring 2011–2018). In addition, we quantified the realized ecological niches of dominant coccolithophore species in the region based on the ecological modeling method (MaxEnt statistics). Results indicated the interannual mean coccolithophore abundance ranged 4,306–11,140 cells L−1. The ecologically important species such as Gephyrocapsa oceanica, Emiliania huxleyi, Algirosphaera robusta, Florisphaera profunda, Umbilicosphaera sibogae, and Umbellosphaera irregularis were identified as dominant species in the coccolithophore community. Based on the ratios of coccoliths and plated coccolithophores, we observed coccolith detachment rates showed a valley near deep chlorophyll maximum layer and peaked in the surface or bottom of euphotic layer which was potentially relevant to near‐surface circulations, nutrients and light availability. From applying the ecological modeling method, we quantified three types of realized niches in coccolithophore species based on mean niche (μ) and breadth of niche (σ) which were consistent with their conventionally vertical biogeography. Our data set could be further incorporated into climatic ecological models.
Calcareous Nannofossil Size and Abundance Response to the Messinian Salinity Crisis Onset and Paleoenvironmental Dynamics
Authors: Mancini A. M. , Grelaud M. , Ziveri P. , Nallino E. , Lozar F.
Published: August 2021

Dwarfism is a common feature affecting organisms across extreme events that characterized the Earth history, frequently referred as the result of “stressed conditions.” To date, no study addressed the morphological and biometric changes across the Messinian Salinity Crisis (MSC), one of the most recent and impacting event occurred in the Mediterranean Sea, historically interpreted as characterized by hypersaline conditions. Here we focus on morpho/biometric changes affecting calcareous nannofossils (CN) toward the MSC onset in order to better constrain the paleoenvironmental dynamics and the loosely defined “stressed conditions” characterizing this interval. Size characterization and absolute abundance of selected CN taxa were performed in the Perales (Spain, Western Mediterranean) and in the Banengo and Pollenzo sections (Italy, Northern Mediterranean). We also tested whether size changes and orbital cyclicity were related through analyzing size and calcite mass of Reticulofenestra minuta using an automated image analysis system of CN recognition (SYRACO). We recorded a significant size reduction affecting the CN taxa involved in the MSC onset bioevent, related to the restriction of the Mediterranean Basin that resulted in increased productivity and enhanced environmental variability, stimulating CN growth rate and decreasing their platelet sizes. Reticulofenestra minuta size and mass correlate with the orbital cyclicity with minimum values during periods of enhanced environmental variability, coinciding with the diatomite deposition in the Sorbas Basin. Our finding reveals that the size change recorded across the MSC onset coincided with the instauration of a productive and highly variable environment, linked to the restriction of the paleo Gibraltar Strait.
Limiting Behavior of the Probability Distribution in Einstein's Bed‐Load Formula and its Improvement
Authors: Wu Haoliang , Cheng Nian‐Sheng , Chiew Yee‐Meng
Published: August 2021

The bed‐load transport rates predicted using Einstein's formula in the low and high transport regimes deviate from the experimental data. The deviation, which becomes significant when the transport rate is extremely low or high, may be solely attributed to the folded Gaussian distribution assumed by Einstein. The trends of an Einstein‐type formula at the limits can be separately determined by considering the limiting behavior of the embedded probability distribution, which facilitates the derivation of a formula that best fits the bed‐load data. By applying a Gamma distribution with the shape parameter equal to 3/2, a modified Einstein's formula is successfully applied to the low and high transport regimes.
Assessing the Impact of ICON/MIGHTI Zonal and Meridional Winds on Upper Atmosphere Weather Specification in a Whole Atmosphere Data Assimilation System: An Observing System Simulation Experiment
Authors: Hsu C.‐T. , Pedatella N. M.
Published: August 2021

Thermospheric data assimilation is limited due to the lack of continuous observation of the neutral state. Recently, the thermospheric wind data from the Michelson Interferometer for Global High‐resolution Thermospheric Imaging (MIGHTI) on NASA's Ionospheric CONnection Explorer (ICON) became available. ICON/MIGHTI provides near‐continuous observations of the mid‐ and low‐latitude thermospheric meridional and zonal winds ICON/MIGHTI observes the thermosphere zonal and meridional winds at low‐middle latitudes between 90 and 300 km during the daytime, and 90–105 and above 210 km during the nighttime. This study assesses the impact of assimilating ICON/MIGHTI winds in the National Center for Atmospheric Research Whole Atmosphere Community Climate Model with thermosphere‐ionosphere eXtension (WACCM‐X) + Data Assimilation Research Testbed (DART) on the specification and short‐term forecasting of the thermosphere. Observing system simulation experiments of WACCM‐X + DART with and without assimilating synthetic ICON/MIGHTI meridional and zonal wind profiles are performed. The result shows that this new data set can correct the wind specification throughout the mid‐ and low‐latitude thermosphere, especially around the 90–160 km altitude region. A notable impact is also shown in the region above 300 km altitude, which is above the altitude of ICON/MIGHTI wind observations. The impact of ICON/MIGHTI data on the zonal wind field is larger than on the meridional wind field. The errors of the ensemble mean from the truth of meridional and zonal wind fields in the mid‐and low‐latitude region are reduced by 6% and 12%, respectively, with the help of ICON/MIGHTI wind data.
A Novel Machine Learning Technique to Identify and Categorize Plasma Waves in Spacecraft Measurements
Authors: Vech Daniel , Malaspina David M.
Published: August 2021

The available magnetic field data from the terrestrial magnetosphere, solar wind and planetary magnetospheres exceeds over hours. Identifying plasma waves in these large data sets is a time consuming and tedious process. In this Paper, we propose a solution to this problem. We demonstrate how self‐organizing maps (SOMs) can be used for rapid data reduction and identification of plasma waves in large data sets. We use 72,000 fluxgate and 110,000 search coil magnetic field power spectra from the Magnetospheric Multiscale Mission () and show how the SOM sorts the power spectra into groups based on their shape. Organizing the data in this way makes it very straightforward to identify power spectra with similar properties and therefore this technique greatly reduces the need for manual inspection of the data. We suggest that SOMs offer a time effective and robust technique, which can significantly accelerate the processing of magnetic field data and discovery of new wave forms.
Revisiting the Partial Ring Current Model: Longitudinal Asymmetry of Ground Magnetic Depression During Geomagnetic Storms
Authors: Ohtani Shinichi
Published: August 2021

During the main phase of geomagnetic storms, the horizontal ground magnetic component is more depressed at dusk than at dawn, which was originally explained by the partial ring current model. Later studies questioned the idea that the ring current intensifies primarily at dusk, and the cause of this dawn‐dusk asymmetry still remains to be understood. The present study targets this old issue by statistically examining SuperMAG geomagnetic (sub‐)indices. The results are summarized as follows: (1) the dawn‐dusk asymmetry is correlated with the enhancement of the dawnside westward auroral electrojet (AEJ); (2) its correlation with the duskside eastward AEJ, which was considered by the classical partial ring current model, is insignificant; (3) the magnetic depression tends to be larger on the dayside than on the nightside, and the asymmetry is correlated with the westward AEJ in the midnight sector; (4) the dawn‐dusk asymmetry enhances typically for 1–2 h, and the day‐night asymmetry for <1 h; (5) the dawn‐dusk and day‐night asymmetries are not correlated with each other. It is suggested that the dawn‐dusk asymmetry is associated with a dawnside wedge current system with an enhanced westward AEJ (1 & 2), and it is suggested to be driven by a substorm‐like process, and possibly also by enhanced global convection (4). The day‐night asymmetry is probably associated with the formation of the substorm wedge current system (3 & 4). Although the associated dawnside and midnight westward AEJs may often enhance simultaneously, they are possibly driven by different processes (4 & 5).
Magma‐Mush Interactions in the Lower Oceanic Crust: Insights From Atlantis Bank Layered Series (Southwest Indian Ridge)
Authors: Boulanger M. , France L. , Ferrando C. , Ildefonse B. , Ghosh B. , Sanfilippo A. , Liu C.‐Z. , Morishita T. , Koepke J. , Bruguier O.
Published: August 2021

Magma migration and differentiation processes are key to understanding the development and evolution of oceanic magma reservoirs. To provide new quantitative geochemical constraints on these processes, we applied a high‐resolution approach to study an interlayered section of the lower oceanic crust sampled at Atlantis Bank, on the (ultra)slow‐spreading Southwest Indian Ridge. The section is characterized by sharp grain‐size layering between fine‐ and coarse‐grained olivine gabbros that is representative of other layered structures described at the Atlantis Bank oceanic core complex. The textures and fabrics of the layers and the nature of their contacts indicate formation by intrusion of a magma (i.e., crystal‐bearing) into an almost solidified coarse‐grained mush. Petrographic observations and in situ incompatible trace element signatures indicate that the fine‐ and coarse‐grained layers record reactive porous migration of melts. Widespread reactive porous flow occurred prior to intrusion within the coarse‐grained gabbro, producing mineral compositions enriched in incompatible elements. The intrusive fine‐grained lithology records a late stage event of localized reactive melt percolation in cm‐scale structures, which lead to strong light rare earth elements depletion relative to heavy rare earth elements. In addition, we highlight the occurrence of interactions at the contacts between layers and partial modification in compositions of the intruded lithology. This layered section likely represents a contact between two larger magma bodies emplaced within the lower crust during accretion, where the type of melt migration (intrusion or porous flow) and the modalities of melt percolation (widespread or localized) strongly govern the composition of the crustal lithologies.
Swell Generation Under Extra‐Tropical Storms
Authors: Hell M. C. , Ayet Alex , Chapron Bertrand
Published: August 2021

Storms propagate over the ocean and create moving patches of strong winds that generate swell systems. Here, we describe the dynamics of wave generation under a moving storm by using a simple parametric model of wave development, forced by a temporally and spatially varying moving wind field. This framework reveals how surface winds under moving storms determine the origin and amplitude of swell events. Swell systems are expected to originate from locations different than the moving high‐wind forcing regions. This is confirmed by a physically informed optimization method that back‐triangulates the common source locations of swell using their dispersion slopes, simultaneously measured at five wave‐buoy locations. Hence, the parametric moving fetch model forced with reanalysis winds can predict the displacement between the highest winds and the observed swell source area. The model further shows that the storm's peak wind speed is the key factor determining swell energy since it determines surface wind gradients that lead to the spatial convergence of wave energy into a much smaller area than the wind fetch. Swell generation can then be described to follow a three‐stage process that outlines a focus area where swell energy is enhanced and slightly displaced from the maximum wind locations. This analysis provides an improved understanding of fetches for extra‐tropical swell systems and may help to identify biases in swell forecast models, air‐sea fluxes, and upper‐ocean mixing estimations.
Airborne Observations of CFCs Over Hebei Province, China in Spring 2016
Authors: Benish Sarah E. , Salawitch Ross J. , Ren Xinrong , He Hao , Dickerson Russell R.
Published: August 2021

In Spring 2016, 27 whole air samples were collected from an aircraft ∼500–∼3,500 m over Hebei Province, China and analyzed for 16 halocarbons, including chlorofluorocarbons (CFCs). Mixing ratios (median, 25th–75th percentiles) of CFC‐11 (281, 255–318 ppt), CFC‐12 (546, 473–591 ppt), CFC‐113 (79, 73–85 ppt), CFC‐114 (22, 19–25 ppt), HCFC‐22 (345, 308–432 ppt), and CCl4 (88, 75–104 ppt) were often observed to be higher than their global tropospheric background levels. The significantly elevated mixing ratios of ozone depleting substances (ODSs) combined with strong correlations with anthropogenic tracers known to have substantial use and emission in this region (HCFC‐22 and CH2Cl2) suggest continuing emissions of multiple Montreal Protocol‐controlled gases at the time of measurement. We use HYSPLIT trajectory clusters and potential source contribution function methods to identify principal transport pathways of CFCs. We find the highest mixing ratios of ODSs in air originating from Inner Mongolia, Hebei, and Shandong. The strong correlations between CFC‐11 and CFC‐12 with the feedstock CCl4 suggest new production is prevalent in all three regions. We find no evidence for new production of CFC‐113, but the strong correlation of CFC‐114 with the feedstock C2Cl4 suggests new production of CFC‐114 from the southeast of China. The findings of this study confirm high mixing ratios of ODSs over Hebei in Spring 2016 and suggest new production and use (rather than release from banks), which is in conflict with the Montreal Protocol agreement that bans the production of CFCs.
Diffusion‐Based Smoothers for Spatial Filtering of Gridded Geophysical Data
Authors: Grooms I. , Loose N. , Abernathey R. , Steinberg J. M. , Bachman S. D. , Marques G. , Guillaumin A. P. , Yankovsky E.
Published: August 2021

We describe a new way to apply a spatial filter to gridded data from models or observations, focusing on low‐pass filters. The new method is analogous to smoothing via diffusion, and its implementation requires only a discrete Laplacian operator appropriate to the data. The new method can approximate arbitrary filter shapes, including Gaussian filters, and can be extended to spatially varying and anisotropic filters. The new diffusion‐based smoother's properties are illustrated with examples from ocean model data and ocean observational products. An open‐source Python package implementing this algorithm, called gcm‐filters, is currently under development.
ARRB1 suppresses the activation of hepatic macrophages via modulating endoplasmic reticulum stress in lipopolysaccharide-induced acute liver injury
Authors: Lei Yiming , Wan Sizhe , Liu Huiling , Zhou Haoxiong , Chen Lingjun , Yang Yidong , Wu Bin
Published: August 2021

Acute liver injury (ALI) caused by multiple inflammatory responses is a monocyte-/macrophage-mediated liver injury that is associated with high morbidity and mortality. Liver macrophage activation is a vital event that triggers ALI. However, the mechanism of liver macrophage activation has not been fully elucidated. This study examined the role of β-arrestin1 (ARRB1) in wild-type (WT) and ARRB1-knockout (ARRB1-KO) mouse models of ALI induced by lipopolysaccharide (LPS), and ARRB1-KO mice exhibited more severe inflammatory injury and liver macrophage activation compared to WT mice. We found that LPS treatment reduced the expression level of ARRB1 in Raw264.7 and THP-1 cell lines, and mouse primary hepatic macrophages. Overexpression of ARRB1 in Raw264.7 and THP-1 cell lines significantly attenuated LPS-induced liver macrophage activation, such as transformation in cell morphology and enhanced expression of proinflammatory cytokines (tumor necrosis factor-α, interleukin-1β, and interleukin-6), while downregulation of ARRB1 by small interfering RNA and ARRB1 deficiency in primary hepatic macrophages both aggravated macrophage activation. Moreover, overexpression of ARRB1 suppressed LPS-induced endoplasmic reticulum (ER) stress in liver macrophages, and inhibition of ER stress impeded excessive hepatic macrophage activation induced by downregulation of ARRB1. Our data demonstrate that ARRB1 relieves LPS-induced ALI through the ER stress pathway to regulate hepatic macrophage activation and that ARRB1 may be a potential therapeutic target for ALI.
Phenotypic plasticity of fungal traits in response to moisture and temperature
Authors: Alster Charlotte J , Allison Steven D , Johnson Nels G , Glassman Sydney I , Treseder Kathleen K
Published: August 2021

Phenotypic plasticity of traits is commonly measured in plants to improve understanding of organismal and ecosystem responses to climate change but is far less studied for microbes. Specifically, decomposer fungi are thought to display high levels of phenotypic plasticity and their functions have important implications for ecosystem dynamics. Assessing the phenotypic plasticity of fungal traits may therefore be important for predicting fungal community response to climate change. Here, we assess the phenotypic plasticity of 15 fungal isolates (12 species) from a Southern California grassland. Fungi were incubated on litter at five moisture levels (ranging from 4–50% water holding capacity) and at five temperatures (ranging from 4–36 °C). After incubation, fungal biomass and activities of four extracellular enzymes (cellobiohydrolase (CBH), β-glucosidase (BG), β-xylosidase (BX), and N-acetyl-β-D-glucosaminidase (NAG)) were measured. We used response surface methodology to determine how fungal phenotypic plasticity differs across the moisture-temperature gradient. We hypothesized that fungal biomass and extracellular enzyme activities would vary with moisture and temperature and that the shape of the response surface would vary between fungal isolates. We further hypothesized that more closely related fungi would show more similar response surfaces across the moisture-temperature gradient. In support of our hypotheses, we found that plasticity differed between fungi along the temperature gradient for fungal biomass and for all the extracellular enzyme activities. Plasticity also differed between fungi along the moisture gradient for BG activity. These differences appear to be caused by variation mainly at the moisture and temperature extremes. We also found that more closely related fungi had more similar extracellular enzymes activities at the highest temperature. Altogether, this evidence suggests that with global warming, fungal biodiversity may become increasingly important as functional traits tend to diverge along phylogenetic lines at higher temperatures.
Computational identification of human ubiquitination sites using convolutional and recurrent neural networks
Authors: Wang Xiaofeng , Yan Renxiang , Wang Yongji
Published: August 2021

Ubiquitination is a very important protein post-translational modification in humans, which is closely related to many human diseases such as cancers.
A highly sensitive fluorescence biosensor for detection of Staphylococcus aureus based on HCR-mediated three-way DNA junction nicking enzyme assisted signal amplification
Authors: Zhang Chuyan , Luo Zewei , Wu Mengfan , Ning Wei , Tian Ziyi , Duan Yixiang , Li Yongxin
Published: August 2021

A novel biosensor for highly sensitive detection of Staphylococcus aureus (S. aureus) was constructed based on the synergistic amplification of hybridization chain reaction (HCR) and nicking enzyme.
The dopaminergic neuroprotective effects of different phytosterols identified in rice bran and rice bran oil
Authors: Zhang Jiali , Zhang Lu , Wu Zhengzhang , Zhang Peng , Liu Ruijie , Chang Ming , Wang Xingguo
Published: August 2021

Phytosterols are important bioactive compounds in rice bran and rice bran oil, and the compositions of different phytosterols in rice bran and rice bran oil were investigated in our previous research.
Electronic properties of metal halide perovskites and their interfaces: the basics
Authors: Zu Fengshuo , Shin Dongguen , Koch Norbert
Published: August 2021

Metal halide perovskites exhibit complex electronic properties. The presently identified fundamental concepts and phenomena governing the electronic behavior of this material class are addressed in this article.
N-Doped carbon encapsulating Bi nanoparticles derived from metal–organic frameworks for high-performance sodium-ion batteries
Authors: Chen Lin , He Xiaojie , Chen Huimin , Huang Shuping , Wei Mingdeng
Published: August 2021

Bi@NC was synthesized successfully by using a Bi-MOF as a precursor. Benefitting from the synergistic effect of the Bi nanoparticles and N-doped carbon matrix, a long-term cycling performance was delivered.
Ultrasensitive broadband photodetectors based on two-dimensional Bi2O2Te films
Authors: Tian Pin , Wu Hongbo , Tang Libin , Xiang Jinzhong , Ji Rongbin , Lau Shu Ping , Teng Kar Seng , Guo Wei , Yao Yugui , Li Lain-Jong
Published: August 2021

A broadband photodetector consisted by Bi2O2Te and n-Si exhibits an ultrasensitive performance in the range of 210 nm to 2400 nm.
Pyrolysis-controlled FeCoNi@hard carbon composites with facilitated impedance matching for strong electromagnetic wave response
Authors: Shen Junyao , Zhang Danfeng , Wu Qibai , Wang Yan , Gao Heng , Yu Jiale , Zeng Guoxun , Zhang Haiyan
Published: August 2021

FeCoNi@hard carbon (HC) microwave absorbers were prepared from FeCoNi nanosheets@polyimide (PI) using suitable pyrolysis temperatures and showed excellent microwave absorption performances with enhanced impedance matching.
A comprehensive review on IoT‐based infrastructure for smart grid applications
Authors: Pal Rohan , Chavhan Suresh , Gupta Deepak , Khanna Ashish , Padmanaban Sanjeevikumar , Khan Baseem , Rodrigues Joel J. P. C.
Published: August 2021

Currently, there is a huge production in the automotive industries and energy consumption resulted into spike in the cost and emissions of greenhouse gases. Hence, an efficient energy utilisation mechanism has become a prime most important factor. Energy and its conservation problem also have raised and become one of the prominent critical factors needed to address. Therefore, the development of smart grid infrastructure is one of the solutions to address the above issue.This article discusses different methods and mechanisms require to manage energy efficiently within the smart grid network using communication technologies and protocols and proposed an integration method of electric vehicles and smart grid using communication networks for charging or discharging electricity and exchanging relevant information. In addition, this paper discusses different integration strategies and multi‐agent system implementation in the smart grid network. The proposed multi‐agent system shows the efficient method for monitoring power flow and maintaining the stability of the grid. The paper also presents the optimal scheduling of charging of electric vehicles in the smart grid network. Finally, the authors investigated and presented many standard communication protocols and their comparisons with respect to different scenarios. This paper discuss different methods and concepts which would require to manage energy efficiently by using recent communication technologies, communication protocols, and sensor technologies.
Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS
Authors: Uzundag M. , Córsico A. H. , Kepler S. O. , Althaus L. G. , Werner K. , Reindl N. , Bell K. J. , Higgins M. , da Rosa G. O. , Vučković M. , Istrate A.
Published: August 2021

Context. The Transiting Exoplanet Survey Satellite (TESS) mission is revolutionizing the blossoming area of asteroseismology, particularly of pulsating white dwarfs and pre-white dwarfs, thus continuing the impulse of its predecessor, the Kepler mission.

Aims. In this paper, we present the observations from the extended TESS mission in both 120 s short-cadence and 20 s ultra-short-cadence mode of two pre-white dwarf stars showing hydrogen deficiency. We identify them as two new GW Vir stars, TIC 333432673 and TIC 095332541. We apply the tools of asteroseismology with the aim of deriving their structural parameters and seismological distances.

Methods. We carried out a spectroscopic analysis and a spectral fitting of TIC 333432673 and TIC 095332541. We also processed and analyzed the high-precision TESS photometric light curves of the two target stars, and derived their oscillation frequencies. We performed an asteroseismological analysis of these stars on the basis of PG 1159 evolutionary models that take into account the complete evolution of the progenitor stars. We searched for patterns of uniform period spacings in order to constrain the stellar mass of the stars. We employed the individual observed periods to search for a representative seismological model.

Results. The analysis of the TESS light curves of TIC 333432673 and TIC 095332541 reveals the presence of several oscillations with periods ranging from 350 to 500 s associated to typical gravity (g)-modes. From follow-up ground-based spectroscopy, we find that both stars have a similar effective temperature (Teff = 120 000 ± 10 000 K) and surface gravity (log g = 7.5 ± 0.5), but a different He/C composition of their atmosphere. On the basis of PG 1159 evolutionary tracks, we derived a spectroscopic mass of M⋆ = 0.58−0.08+0.16 M⊙ for both stars. Our asteroseismological analysis of TIC 333432673 allowed us to find a constant period spacing compatible with a stellar mass M⋆ ∼ 0.60 − 0.61 M⊙, and an asteroseismological model for this star with a stellar mass M⋆ = 0.589 ± 0.020 M⊙, as well as a seismological distance of d = 459−156+188 pc. For this star, we find an excellent agreement between the different methods to infer the stellar mass, and also between the seismological distance and that measured with Gaia (dGaia = 389−5.2+5.6 pc). For TIC 095332541, we have found a possible period spacing that suggests a stellar mass of M⋆ ∼ 0.55 − 0.57 M⊙. Unfortunately, we have not been able to find an asteroseismological model for this star.

Conclusions. Using the high-quality data collected by the TESS space mission and follow-up spectroscopy, we have been able to discover and characterize two new GW Vir stars. The TESS mission is having, and will continue to have, an unprecedented impact on the area of white-dwarf asteroseismology.
Mitral Annular Calcification in Marfan Syndrome: A 38-Year Follow-Up Observation
Authors: Horiuchi Kazutaka
Published: August 2021

Background Mitral annular calcification (MAC) associated with Marfan syndrome is rare in comparison with that frequently found in elderlies with valvular disease.

Case Presentation A 17-year-old woman with Marfan syndrome underwent mitral valve replacement for severe mitral regurgitation. Preoperative examination showed mitral valve prolapse and a dense C -shaped MAC. We evaluated MAC and adjacent area, respectively, in postoperative 18 and 38 years, and neither progression nor expansion of calcification was observed.

Conclusion MAC associated with Marfan syndrome is more likely to be caused by stresses due to valve prolapse than by connective tissue disorder.