bluuebunny/crossref_metadata_2025 huggingface dataset:
Lehrkräfteeinschätzungen zu Unterrichtsqualität mit digitalen Medien: Zusammenhänge zur wahrgenommenen technischen Schulausstattung, Medienunterstützung, digitalen Kompetenzselbsteinschätzungen und Wertüberzeugungen
Authors: Quast Jennifer , Rubach Charlott , Lazarides Rebecca
Published: July 2021

Obwohl der Einsatz digitaler Medien in Lehr-Lern-Prozessen zunehmend an Bedeutung gewinnt, befassen sich Studien nur vereinzelt mit der Frage, inwiefern digitale Medien im Unterricht zur Umsetzung von Unterrichtsqualitätsdimensionen genutzt werden. Gleichzeitig ist wenig über die Bedingungsfaktoren einer solchen qualitätsvollen Umsetzung von Unterricht mit digitalen Medien bekannt. Die vorliegende Studie untersucht vor diesem Hintergrund, inwiefern Schulmerkmale vermittelt über Lehrkräftemerkmale dazu beitragen, dass Lehrkräfte digitale Medien nutzen, um im Unterricht zu strukturieren, kognitiv zu aktivieren, konstruktiv zu unterstützen sowie zu individualisieren. Ausgewertet wurden Daten von 280 Lehrkräften an Schulen der Sekundarstufe in Deutschland (52,1 % weiblich, Alter:M = 43,88, SD = 10,00). Die Ergebnisse des Strukturgleichungsmodells verweisen darauf, dass die Zufriedenheit mit der schulischen Unterstützung zum Einsatz digitaler Medien vermittelt über die digitalen (berufsunabhängigen) Kompetenzselbsteinschätzungen in positivem Zusammenhang mit der Nutzung digitaler Medien zum Zwecke der Individualisierung, kognitiven Aktivierung und konstruktiven Unterstützung im Unterricht steht. Die von Lehrkräften berichtete vielfältige technische Schulausstattung sowie die berichteten positiven Wertüberzeugungen in Bezug auf den Einsatz digitaler Medien im Unterricht sind direkt positiv mit der Nutzung digitaler Medien zur Umsetzung der Unterrichtsqualitätsdimensionen assoziiert.
A two-stage information retrieval system based on interactive multimodal genetic algorithm for query weight optimization
Authors: Cong Hao , Chen Wei-Neng , Yu Wei-Jie
Published: July 2021

Query weight optimization, which aims to find an optimal combination of the weights of query terms for sorting relevant documents, is an important topic in the information retrieval system. Due to the huge search space, the query optimization problem is intractable, and evolutionary algorithms have become one popular approach. But as the size of the database grows, traditional retrieval approaches may return a lot of results, which leads to low efficiency and poor practicality. To solve this problem, this paper proposes a two-stage information retrieval system based on an interactive multimodal genetic algorithm (IMGA) for a query weight optimization system. The proposed IMGA has two stages: quantity control and quality optimization. In the quantity control stage, a multimodal genetic algorithm with the aid of the niching method selects multiple promising combinations of query terms simultaneously by which the numbers of retrieved documents are controlled in an appropriate range. In the quality optimization stage, an interactive genetic algorithm is designed to find the optimal query weights so that the most user-friendly document retrieval sequence can be yielded. Users’ feedback information will accelerate the optimization process, and a genetic algorithm (GA) performs interactively with the action of relevance feedback mechanism. Replacing user evaluation, a mathematical model is built to evaluate the fitness values of individuals. In the proposed two-stage method, not only the number of returned results can be controlled, but also the quality and accuracy of retrieval can be improved. The proposed method is run on the database which with more than 2000 documents. The experimental results show that our proposed method outperforms several state-of-the-art query weight optimization approaches in terms of the precision rate and the recall rate.
Method for designing the optimal sealing depth in methane drainage boreholes to realize efficient drainage
Authors: Yi Minghao , Wang Liang , Hao Congmeng , Liu Qingquan , Wang Zhenyang
Published: July 2021

The purpose of underground methane drainage technology is to prevent methane disasters and enable the efficient use of coal mine methane (CMM), and the sealing depth is a key factor that affects the performance of underground methane drainage. In this work, the layouts of in-seam and crossing boreholes are considered to analyze the stress distribution and failure characteristics of roadway surrounding rock through a numerical simulation and field stress investigation to determine a reasonable sealing depth. The results show that the depths of the plastic and elastic zones in two experimental coal mines are 16 and 20 m respectively. Borehole sealing minimizes the air leakage through the fractures around the roadway when the sealing material covers the failure and plastic zones, and the field test results for CMM drainage at different sealing depths indicate that the CMM drainage efficiency increases with increasing sealing depth but does not change once the sealing depth exceeds the plastic zone. Moreover, sealing in the high-permeability roadway surrounding rock does not have a strong influence on the borehole sealing performance. Considering these findings, a new CMM drainage system for key sealing in the low-permeability zone was developed that is effective for improving the CMM drainage efficiency and prolonging the high-concentration CMM drainage period. The proposed approach offers a valuable quantitative analysis method for selecting the optimum sealing parameters for underground methane drainage, thereby improving considerably the drainage and utilization rates of CMM.
Compound-mode crack propagation law of PMMA semicircular-arch roadway specimens under impact loading
Authors: Li Chengxiao , Guo Dongming , Zhang Yuantong , An Chen
Published: July 2021

An underground roadway usually contains defects of various types, and when the roadway is subjected to external loading, the locations of those defects influence the roadway by differing degrees. In this study, to study how the locations of defects affect crack propagation in a roadway, specimens with tunnel-type voids were made using polymethyl methacrylate, and the stress wave produced by a bullet impacting an incident rod was used as the impact load. Meanwhile, the variations in crack speed, displacement, and dynamic stress intensity factor during crack propagation were obtained using an experimental system of digital laser dynamic caustics, and the commercial software ABAQUS was used for numerical simulations. From the experiments and numerical simulations, the crack propagation path was verified and the impact fracture behavior of a semicircular-arch roadway with different defect positions was presented. The results show that when the pre-fabricated crack is on the central axis of the sample, the crack propagation is purely mode I; when the pre-fabricated crack is 5 mm from the central axis, the crack propagation alternates between mode I and a mixture of modes I and II; when the pre-fabricated crack is at the edge of the semicircular-arch roadway, the crack propagation follows the I–II mixed mode.
Explicit Deligne pairing
Authors: Dolce Paolo
Published: July 2021

We give an explicit formula for the Deligne pairing for proper and flat morphisms $$f:X\rightarrow S$$

f
:
X
→
S

of schemes, in terms of the determinant of cohomology. The whole construction is justified by an analogy with the intersection theory on non-singular projective algebraic varieties.
Performance assessment and optimization of a helical Savonius wind turbine by modifying the Bach’s section
Authors: Zadeh M. Niyat , Pourfallah M. , Sabet S. Safari , Gholinia M. , Mouloodi S. , Ahangar A. Taheri
Published: July 2021

In this paper, we attempted to measure the effect of Bach’s section, which presents a high-power coefficient in the standard Savonius model, on the performance of the helical Savonius wind turbine, by observing the parameters affecting turbine performance. Assessment methods based on the tip speed ratio, torque variation, flow field characterizations, and the power coefficient are performed. The present issue was stimulated using the turbulence model SST (k- ω) at 6, 8, and 10 m/s wind flow velocities via COMSOL software. Numerical simulation was validated employing previous articles. Outputs demonstrate that Bach-primary and Bach-developed wind turbine models have less flow separation at the spoke-end than the simple helical Savonius model, ultimately improving wind turbines’ total performance and reducing spoke-dynamic loads. Compared with the basic model, the Bach-developed model shows an 18.3% performance improvement in the maximum power coefficient. Bach’s primary model also offers a 12.4% increase in power production than the initial model’s best performance. Furthermore, the results indicate that changing the geometric parameters of the Bach model at high velocities (in turbulent flows) does not significantly affect improving performance.
Frieden für wen? Sicherheitspolitik im Kontext der Gewalt gegen Menschenrechtsaktivist*innen in Kolumbien
Authors: Figari Layús Rosario
Published: July 2021

In den letzten Jahren, insbesondere seit der Unterzeichnung des Friedensabkommens zwischen der kolumbianischen Regierung und der FARC-Guerilla Ende 2016, sind Menschenrechts- und Umweltaktivist*innen in vielen Regionen Kolumbiens mit zunehmenden Angriffen und Einschüchterungen konfrontiert. In diesem Zusammenhang hat die kolumbianische Regierung eine Reihe von Maßnahmen implementiert, um dieser zunehmenden Gewalt zu begegnen. Dieser Beitrag analysiert, wie die dieser staatlichen Initiative zugrunde liegenden Konzepte von „Schutz“ und „Sicherheit“ sowie ihre Umsetzungsdynamiken schwierige Folgen für einen effektiven Schutz von gefährdeten Akteur*innen der Zivilgesellschaft in Kolumbien gebracht haben. Dafür werden die Rolle, die Auswirkungen und die Herausforderungen solcher Programme berücksichtigt, die oft Aktivist*innen nicht langfristig schützen können, sondern sogar viele der gefährdeten Akteur*innen ausschließen und oft sogar in größere Gefahr bringen. Welche staatlichen Initiativen werden in Kolumbien implementiert, um der zunehmenden Gewalt zu begegnen und die Zivilgesellschaft zu schützen? Welche Auswirkungen haben diese staatlichen Maßnahmen in Kolumbien bisher gezeigt und welche Herausforderungen sind immer noch zu identifizieren?
Landing in Ski Jumping: A Review About its Biomechanics and the Connected Injuries
Authors: Bessone Veronica , Schwirtz Ansgar
Published: July 2021

The present review deals with the current scientific knowledge related with ski jump landing. A specific focus is given on the landing biomechanics, the methods utilized for its analysis and the injuries connected to the landing phase. Despite the demonstrated importance for the safety and the performance of ski jumpers, the landing and its preparation are rarely investigated. In this paper, after having firstly described the execution of landing and its preparation and the reason why is important to analyze it, an overview of the current status of the research related to the landing biomechanics is reported (kinetics, kinematics, electromyographic activation, aerodynamics, computer simulation). The third part describes the methods and technologies utilized in literature to analyze the landing and its preparation (video cameras, inertial sensors, force insoles, wind tunnel and computer simulation). After that, an overview of the injuries related to landing is reported. The final section proposes future research in the field of biomechanics of ski jump landing in different fields, such as computer simulations, kinematic analysis, equipment development and biomechanics of female athletes.
Convergence of Public Participation, Participatory Design and NLP to Co-Develop Circular Economy
Authors: Dyer Mark , Wu Shaoqun , Weng Min-Hsien
Published: July 2021

The concept of a circular economy is at a crossroads. To date, it has been largely driven by top-down national or trans-national legislation such as EU Circular Economy Package or Chinese Circular Economy Promotion. Bottom-up or grassroots engagement has been minimal and innovation has been largely restricted to use of 3R or 4R frameworks to reduce, reuse, recycle materials and products or recover waste as energy. Greater implementation of a circular economy needs a paradigm shift in public attitudes coupled with greater innovation that moves from 3R to 9R framework. Building on the insights gained from the successful transition of two Scandinavian cities of Växjö and Sønderborg to becoming fossil fuel-free economies, the article explores use of natural language processing tools to create shared narratives and stories from large format public engagement that expresses common interests, values and priorities that in turn can contribute to a participatory design of a circular economy. The article uses published data from Christchurch ‘Share an Idea’ as a case study.
Transfer facilitation effects of morphological awareness on multicharacter word reading in Chinese as a foreign language
Authors: Ke Sihui (Echo) , Koda Keiko
Published: July 2021

This study examined the transfer facilitation effects from English morphological awareness on Chinese multicharacter word reading in English-speaking adult learners of Chinese as a foreign language (CFL). Fifty English-speaking American university CFL learners participated in our study who measured their English morphological awareness, Chinese morphological awareness, Chinese linguistic knowledge, Chinese word reading, and working memory. There were three major findings: (1) with approximately three years of formal Chinese instruction and limited Chinese print input, English-speaking adult learners of Chinese developed sensitivity to the internal morphological structure of multicharacter words in Chinese. (2) English morphological awareness did not directly contribute to Chinese bimorphemic three-character pseudoword reading yet contributed indirectly via the joint serial mediation by Chinese morphological awareness and Chinese monomorphemic two-character real word reading. (3) There was no additional influence from Chinese linguistic knowledge on Chinese word reading. And, English morphological awareness explained about 3.64% of the variance in second language Chinese bimorphemic three-character pseudoword reading. Discussion is provided regarding the transfer facilitation mechanism through which first language morphological awareness contributes to adult second language reading acquisition.
Examining the growth trajectories and cognitive predictors of reading in a consistent orthography: Evidence from a 10-year longitudinal study
Authors: Georgiou George K. , Inoue Tomohiro , Papadopoulos Timothy C. , Parrila Rauno
Published: July 2021

We examined the growth trajectories of reading in a consistent orthography (Greek) in two developmental periods (from Grade 1 to Grade 4 and from Grade 4 to Grade 10) and what cognitive skills predict the growth patterns. Seventy-five Greek-speaking children were assessed in Grades 1, 2, 4, 6, and 10 on word-, nonword-, and text-reading fluency. In Grades 1 and 4, they were also assessed on phonological awareness, rapid naming, phonological memory, orthographic knowledge, and articulation rate. Results of growth curve modeling showed that during the first developmental period, there was a rapid initial growth from Grade 1 to Grade 2 followed by a less rapid growth from Grade 2 to Grade 4. In the second developmental period, the slow growth continued. In both developmental periods, rapid naming and orthographic knowledge predicted the initial status of all reading outcomes and phonological memory predicted the initial status of nonword-reading fluency. Phonological awareness predicted the initial status of nonword-reading fluency in the first developmental period and the initial status of word- and text-reading fluency in the second developmental period. None of the cognitive skills predicted the growth rate in reading skills. Theoretical and practical implications of these findings are discussed.
Working memory training enhances complex syntax in children with Developmental Language Disorder
Authors: Delage Hélène , Stanford Emily , Durrleman Stephanie
Published: July 2021

Linguistic deficits attested in children with Developmental Language Disorder (DLD) have been explained in terms of limitations in working memory (WM). The goal of this research is to assess whether a tailored WM program can improve the syntactic abilities of children with DLD and those with typical development (TD). We created a novel iPad application consisting of five activities specifically designed to train the components of WM that have been shown to be the most predictive of performance on tests assessing complex syntax. Thirty-two children with DLD (M = 9;0) and 18 with TD (M = 8;5) followed the WM training (lasting 12 hours). Results show significant improvement in verbal WM (direct effects) in both TD and DLD groups, and in sentence repetition (transfer effects) in the DLD group, with the most pronounced improvements observed for complex syntactic structures. This progression is not observed for 38 age-matched children of the same age who followed an alternative, global scholastic training (20 DLD, 18 TD), which proves the specific efficacy of our WM training. The logical next step will be to incorporate the training into the therapy of children with DLD in order to reinforce the potential benefit of their interventions.
Products and projective limits of continuous valuations on T0 spaces
Authors: Goubault-Larrecq Jean
Published: July 2021

We show analogues of the Daniell–Kolmogorov and Prohorov theorems on the existence of projective limits of measures, in the setting of continuous valuations on T0 topological spaces.
Prenatal diagnosis of a right ventricular outpouching: a report of case
Authors: Subaşı Berivan , Akbaş Tolga , Demir Fadli
Published: July 2021

We report a case of a right ventricular outpouching diagnosed during prenatal period. We defined it as an aneurysm because of its thin, hypokinetic wall, and wide neck connecting to the ventricle. Ventricular aneurysms, especially right ventricular aneurysms, are very rare cardiac malformations. Therefore, we describe a rare case of right ventricular aneurysm and the diagnostic features, differential diagnosis, and clinical features of ventricular aneurysms.
Spatiotemporal Trends and Variability in the Centroid of the Northern Hemisphere's Circumpolar Vortex
Authors: Bushra Nazla , Rohli Robert V.
Published: July 2021

Recent previous research has established the “sharpest gradient” approach to defining the circumpolar vortex and has identified correlations of the area and circularity of the Northern Hemisphere's circumpolar vortex (NHCPV) to important atmospheric‐oceanic teleconnections. However, because geographical shifts in the NHCPV, independent of area or circularity changes, could affect surface environmental conditions, this research addresses the question of the extent to which the NHCPV centroid undergoes such shifts, both intra‐ and inter‐annually. Results show that during the 1979–2017 period, the centroid has moved less on a daily basis in more recent years, perhaps indicative of a stabilization in circulation, with annual and semi‐annual periodicities in the daily distance moved. A consistent preference toward the Eastern Hemisphere is evident by the displacement of the centroids toward the Pacific basin throughout the study period. Collectively, these results indicate the mid‐tropospheric response to the near‐surface warming.
Nonlinear Magnetic Gradients and Complete Magnetic Geometry From Multispacecraft Measurements
Authors: Shen Chao , Zhang Chi , Rong Zhaojin , Pu Zuyin , Dunlop Malcolm W. , Escoubet C. Philippe , Russell C. T. , Zeng Gang , Ren Nian , Burch James L. , Zhou Yufei
Published: July 2021

Topological configurations of the magnetic field play key roles in the dynamics of space plasmas. This study presents a novel algorithm that can estimate the quadratic magnetic gradient as well as the complete geometrical features of magnetic field lines, based on magnetic field and current density measurements by a multiple spacecraft constellation at four or more points. The explicit estimators for the linear and quadratic gradients, the apparent velocity of the magnetic structure and the curvature and torsion of the magnetic field lines can be obtained with well‐predicted accuracies. The feasibility and accuracy of the method have been verified with two demonstrations. The algorithm has been successfully applied to exhibit the geometrical structure of a flux rope. This algorithm has wide applications for studying a variety of magnetic configurations in space plasmas.
Detrital Zircon U‐Pb Age Distribution and Hf Isotopic Constraints From the Terrigenous Sediments of the Song Chay Suture Zone (NE Vietnam) and Their Paleogeographic Implications on the Eastern Paleo‐Tethys Evolution
Authors: Wang Yin , Lin Wei , Faure Michel , Lepvrier Claude , Chu Yang , Van Nguyen Vuong , Thu Hoai Luong Thi , Wei Wei , Liu Fei , Van Vu Tich
Published: July 2021

The location of the suture zone between the South China Block (SCB) and the Indochina Block (IB) is disputed. Recently, along the Song Chay (Chay river) belt, a mélange zone was proposed as a potential suture zone of the SCB and IB. However, the provenance and age of the Song Chay mélange is poorly known. In order to better constrain the age and provenance of the elements forming the Song Chay mélange, nine samples of detrital material, and one orthogneiss were subjected to zircon U‐Pb and Hf isotope analysis. Detrital zircons from the silty matrix of the Song Chay mélange record three major Neoproterozoic age clusters at 580–650, 700–800, and 900–1,000 Ma, which correspond well to the substratum of the SCB. Two minor Late and Early Paleozoic age groups at 270–330, and 420–500 Ma, with mainly negative εHf(t) values were also recovered. We consider that the zircons in the matrix of the mélange were mainly derived from the subducting plate, namely the SCB. This interpretation is supported by the occurrence of lensoid sandstone blocks, representing the substratum of the SCB, included into the mélange. The deposition age of the Song Chay mélange is between 310 and 250 Ma. Our results demonstrate that in an ophiolitic mélange, the detrital material does not invariably come from the overriding plate, but at the onset of the collision, the subducting continental plate may also supply the terrigenous material.
Impact of Atmospheric Pressure Fluctuations on Nonequilibrium Transport of Volatile Organic Contaminants in the Vadose Zone: Experimental and Numerical Modeling
Authors: Qi Shengqi , Wang Yidong , Wang Liuwei , Luo Jian , Hou Deyi
Published: July 2021

Atmospheric pressure fluctuations can induce subsurface airflow, affecting Volatile Organic Compound (VOC) contaminant migration in the vadose zone. When modeling this process, traditional vapor intrusion models have relied on the assumption of local equilibrium conditions and neglected kinetic mass transfer processes among different phases. In this study, a nonequilibrium multiphase flow and transport model was developed to investigate the impact of atmospheric pressure fluctuations on VOC release from groundwater to the atmosphere. Kinetic mass transfer processes between vapor & liquid phases, and between liquid & solid phases were taken into consideration. A series of soil column experiments with downward/upward pumped gas flow were conducted to validate the model. The experimental results imply the necessity to use nonequilibrium models for quantifying the impact of atmospheric pressure fluctuation. The validated model was used to investigate the role of atmospheric pressure fluctuations for various practical hydrogeologic settings under daily pressure fluctuations. It was found that when the soil organic carbon content is relatively large, the nonequilibrium model more accurately represents VOC migration than a traditional equilibrium model. Therefore, this study suggests the need to apply nonequilibrium vapor intrusion models at sites with high soil organic matter content.
Stochastic Simulation of Tropical Cyclones for Risk Assessment at One Go: A Multivariate Functional PCA Approach
Authors: Yang Chi , Xu Jing , Yin Jianming
Published: July 2021

A multivariate functional principal component analysis approach to the full‐track simulation of tropical cyclones (TCs) is developed for risk assessment. Elemental variables of TC along the track necessary for risk assessment, such as center coordinates, maximum wind speed, minimum central pressure and ordinal dates, can be simulated simultaneously at one go, using solely the best‐track data with no data supplemented from any other sources. The simulation model is optimally determined by means of the ladle estimator. A TC occurrence model using the Conway–Maxwell–Poisson distribution is proposed as well, by which different dispersion features of annual occurrence can be represented in a unified manner. With the occurrence model, TCs can be simulated on an annual basis. The modeling and simulation process is programmed and fully automated such that little manual intervention is required, which greatly improves the modeling efficiency and reduces the turnaround time, especially when newly available TC data are incorporated periodically into the model. Comprehensive evaluation shows that this approach is capable of generating high‐performance synthetic TCs in terms of distributional and extreme value features, which can be used in conjunction with wind field and engineering vulnerability models to estimate economic and insurance losses for governments and insurance/reinsurance industry.
High‐Resolution Elemental Record From the Holocene Sediments of an Alpine Lake in the Central Altai Mountains: Implications for Arctic Sea‐Ice Variations
Authors: Sun Qing , Daryin Andrei , Zhao Jiayu , Xie Manman , Darin Fedor , Rakshun Yakov , Su Youliang , Dong Haowei , Guoqiang Chu  , Wang Shuxian
Published: July 2021

It is well known that Arctic sea ice and Arctic amplification have played an important role in recent climate change in middle to high latitudes of the Northern Hemisphere. We present a high‐resolution elemental data set, spanning the past 9,000 years, obtained using in‐situ synchrotron radiation X‐ray fluorescence measurements of a lake sediment core from Lake Shuang in the Altai Mountains. Based on calibration against the local instrumental climatic record, the Rb/Sr ratio of the sediments is interpreted as an indicator of weathering intensity, which is related to precipitation and temperature variations. There is very little bromine in the granites and moyites in the catchment of Lake Shuang, and the sedimentary Br is derived primarily from wet deposition originating from precipitation and enriched by biogenic processes in this open lake system. The Br variation is positively correlated with local precipitation. The Rb/Sr and Br time series show distinct decadal‐scale to millennial‐scale cycles that are similar to those of Arctic sea‐ice variations, which implies the important role of Artic sea ice in modulating environmental change at Lake Shuang. Our results support a previous suggestion that sea ice loss would cause an increase in atmospheric water vapor content in the Arctic, resulting in the frequent incursion of cold air masses from the Arctic into middle latitudes, and leading to increased snow cover and precipitation, and vice versa.
Survey of Juno Observations in Jupiter's Plasma Disk: Density
Authors: Huscher E. , Bagenal F. , Wilson R. J. , Allegrini F. , Ebert R. W. , Valek P. W. , Szalay J. R. , McComas D. J. , Connerney J. E. P. , Bolton S. , Levin S. M.
Published: July 2021

We explore the variation in plasma conditions through the middle magnetosphere of Jupiter with latitude and radial distance using Juno‐JADE measurements of plasma density (electrons, protons, sulfur, and oxygen ions) surveyed on Orbits 5–26 between March 2017 and April 2020. On most orbits, the densities exhibit regular behavior, mapping out a disk between 10 and 50 RJ (Jovian radii). In the disk, the heavy ions are confined close to the centrifugal equator which oscillates relative to the spacecraft due to the ∼10° tilt of Jupiter's magnetic dipole. Exploring each crossing of the plasma disk shows there are some occasions where the density profiles are smooth and well‐defined. At other times, small‐scale structures suggest temporal and/or spatial variabilities. There are some exceptional orbits where the outer regions (30–50 RJ) of the plasma disk show uniform depletion, perhaps due to enhanced ejection of plasmoids down the magnetotail, possibly triggered by solar wind compression events.
3D Geodynamic Models for HP‐UHP Rock Exhumation in Opposite‐Dip Double Subduction‐Collision Systems
Authors: Wang Xinxin , Kaus Boris J. P. , Yang Jianfeng , Wang Kun , Li Yang , Chen Ling , Zhao Liang
Published: July 2021

The dynamics of high pressure (HP) and ultra‐high pressure (UHP) rock exhumation in opposite‐dip double subduction‐collision systems remain enigmatic. Here, we present 3D thermo‐mechanical numerical models to study the geodynamics of continental‐margin subduction, collision, and crustal exhumation of HP‐UHP metamorphic rocks in oppositely dipping adjacent subduction zones. In our model setups, an initial transform‐fault separates a purely oceanic subduction zone from an adjacent oceanic subduction zone that in time transforms into continental‐margin subduction. The results show that most simulations cause continental‐margin deep subduction within the collisional belts. In contrast to the results of 2D and 3D single subduction‐collision systems, the slab‐slab interactions strongly modify the down‐channel Couette flow and the up‐channel Poiseuille flow in the interplate region when the plate edges are close to each other. This prevents the exhumation of UHP metamorphic rocks to the Earth's surface. However, far from the interplate region, rapid exhumation of UHP rocks occurs in Alpine‐type models with a low Moho temperature, strong lower crust, and fast upper‐plate divergence, whereas the Taiwan‐type models occur for a high Moho temperature, weak lower crust, fast convergence, fast erosion, and are likely to facilitate rapid dome‐like HP exhumation. Based on our results, we suggest that the main characteristics, such as deep crustal subduction and rapid exhumation of HP‐UHP metamorphic rocks during mountain building in Taiwan (∼8 Ma to present) and in the Western Alps (∼49–35 Ma), may be the result of opposite‐dip double subduction‐collision systems.
Toward Parametrization of Precipitating Shallow Cumulus Cloud Organization via Moisture Variance
Authors: Thomas Marius Levin , Bašták Ďurán Ivan , Schmidli Juerg
Published: July 2021

The influence of the initial vertical moisture profile on precipitating shallow cumulus cloud organization in terms of the column‐averaged moisture variance is investigated using large‐eddy simulations. Five idealized simulations based on the Rain in Cumulus over the Ocean field experiment with different initial moisture profiles are investigated. All cases simulate precipitating shallow cumulus convection in a marine sub‐tropical region under large‐scale subsidence. The results show that the moisture variance is mainly generated through the interaction of the moisture flux and the moisture gradient in the gradient production term at the top of the boundary layer. The development is characterized by three regimes: initial, transition, and quasi‐steady regime. During the initial regime, the moisture gradient is built up by moisture accumulation until precipitating convection starts. Within the transition regime, precipitation enables mesoscale cloud organization with enhanced convective activity and moisture fluxes. The moisture variance increases from the moist to the dry initial moisture profiles. In a following quasi‐steady regime, the moisture variance is approximately preserved. Thereby, the initial moisture gradient between the average sub‐cloud layer and the free atmosphere is found to be an important factor for the generation of the quasi‐steady column‐averaged moisture variance. The result suggests that a resolved‐scale variable like the moisture gradient can be used to estimate the quasi‐steady state conditions resulting from cloud organization. This finding may serve as a starting point for the parametrization of the subgrid scale cloud organization caused by precipitating shallow convection.
Event Scale Relationships of DOC and TDN Fluxes in Throughfall and Stemflow Diverge From Stream Exports in a Forested Catchment
Authors: Ryan Kevin A. , Adler Thomas , Chalmers Ann , Perdrial Julia , Shanley James B. , Stubbins Aron
Published: July 2021

Aquatic fluxes of carbon and nutrients link terrestrial and aquatic ecosystems. Within forests, storm events drive both the delivery of carbon and nitrogen to the forest floor and the export of these solutes from the land via streams. To increase understanding of the relationships between hydrologic event character and the relative fluxes of carbon and nitrogen in throughfall, stemflow and streams, we measured dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) concentrations in each flow path for 23 events in a forested watershed in Vermont, USA. DOC and TDN concentrations increased with streamflow, indicating their export was limited by water transport of catchment stores. DOC and TDN concentrations in throughfall and stemflow decreased exponentially with increasing precipitation, suggesting that precipitation removed a portion of available sources from tree surfaces during the events. DOC and TDN fluxes were estimated for 76 events across a 2‐year period. For most events, throughfall and stemflow fluxes greatly exceeded stream fluxes, but the imbalance narrowed for larger storms (>30 mm). The largest 10 stream events exported 40% of all stream event DOC whereas those same 10 events contributed 14% of all throughfall export. Approximately 2–5 times more DOC and TDN was exported from trees during rain events than left the catchment via streams annually. The diverging influence of event size on tree versus stream fluxes has important implications for forested ecosystems as hydrological events increase in intensity and frequency due to climate change.
Intensified Soil Moisture Extremes Decrease Soil Organic Carbon Decomposition: A Mechanistic Modeling Analysis
Authors: Liang Junyi , Wang Gangsheng , Singh Shikha , Jagadamma Sindhu , Gu Lianhong , Schadt Christopher W. , Wood Jeffrey D. , Hanson Paul J. , Mayes Melanie A.
Published: July 2021

Earth system models have predicted that there will be more frequent and severe precipitation and drought events in terrestrial ecosystems. Microbially mediated decomposition of soil organic carbon (SOC) tends to increase as soils wet and decrease as soils dry. However, the long‐term SOC change under intensified moisture extremes remains poorly known as it depends on the frequency and intensity of soil drying and wetting. In this study, we explored long‐term SOC dynamics under scenarios of alternating drying‐wetting cycles using the Microbial‐ENzyme Decomposition model, a mechanistic microbial model. The model was parameterized with 11 years of observations from a temperate deciduous broadleaf forest site, showing satisfactory model performance in both model calibration (R2 = 0.67) and validation (R2 = 0.69) against heterotrophic respiration. We then used the model to simulate the long‐term SOC dynamics under five scenarios of alternating drying‐wetting cycles with different frequencies and severities over a period of 100 years. Results showed that the changes in active microbial biomass C and the corresponding turnover rates of SOC pools were more sensitive to soil drying than soil wetting. As a result, the cumulative soil carbon emission from microbial respiration decreased by 433.7 g C m−2 after the 100‐year simulation in the highest frequency and intensity moisture scenario, but was not significantly affected by the lowest frequency and intensity scenario. This study emphasizes the nonlinear response of SOC decomposition to soil moisture changes, which causes decreased decomposition by microbes under drying that is, not compensated by increased decomposition under wetting conditions.
The Role of Subduction Interface and Upper Plate Strength on Back‐Arc Extension: Application to Mediterranean Back‐Arc Basins
Authors: Erdős Zoltán , Huismans Ritske S. , Faccenna Claudio , Wolf Sebastian G.
Published: July 2021

While there has been a lot of work focusing on improving our understanding of divergent and convergent plate boundaries, the intricate nature of back‐arc extension, where subduction and large‐scale extension occur and interact in close, is yet to be explored properly. It has long been proposed that the strength of the subduction interface, which depends among others on the amount of subducted sediments, plays a pivotal role in subduction dynamics. Here, we investigate the role of back‐arc rheology and subduction interface strength on the deformation style of the overriding plate. Using two‐dimensional thermomechanical model experiments, we demonstrate, that the presence of a weak mantle–lithospheric domain in the overriding plate can result in back‐arc breakup even during the subduction of narrow, land‐locked oceanic basins such as those found in the Mediterranean region. The thinning of the back‐arc mantle–lithosphere results in a weaker overriding plate, hence a lower slab‐pull force is sufficient to initiate back‐arc extension. Convective thinning at the subduction interface also reduces the length of the interface, reducing the portion of slab‐pull lost as energy dissipation. A weak plate interface, can also reduce the energy dissipated along the subduction zone, leading to earlier extension. A detailed analysis of the forces shaping the overriding plate stress field shows that transmission of slab‐pull force has a predominant role while viscous basal drag has a negligible effect in our experiments. Our results compare favorably with large‐scale characteristics of land‐locked Mediterranean back‐arc basins such as the North Tyrrhenian basin and the Pannonian basin.
Acoustic Backscatter and Attenuation Due to River Fine Sediments: Experimental Evaluation of Models and Inversion Methods
Authors: Vergne Adrien , Berni Céline , Le Coz Jérôme , Tencé Florent
Published: July 2021

The hydroacoustic monitoring of suspended sediment concentration (SSC) in rivers is based on the inversion of backscatter and attenuation models. To evaluate such models, acoustic backscatter and attenuation were measured from a homogeneous suspension of fine river sediments (clay) in a laboratory tank at various concentrations in the range 1–18 g/l. Agreement between the modeled and measured acoustic backscatter and attenuation values was found to be relatively poor. The results are highly sensitive to particle size and shape which come with large measurement uncertainties and they can be significantly improved by adjusting plausible particle parameters. Various inversion methods combining single or multiple frequencies, analysis of backscatter and/or attenuation, spherical or oblate shape hypothesis for particles and fixed or estimated lognormal grain size distribution are tested. The most promising inversion methods using both backscatter and attenuation information led to accurate SSC estimates.
Efficient Discretization‐Independent Bayesian Inversion of High‐Dimensional Multi‐Gaussian Priors Using a Hybrid MCMC
Authors: Reuschen Sebastian , Jobst Fabian , Nowak Wolfgang
Published: July 2021

In geostatistics, Gaussian random fields are often used to model heterogeneities of soil or subsurface parameters. To give spatial approximations of these random fields, they are discretized. Then, different techniques of geostatistical inversion are used to condition them on measurement data. Among these techniques, Markov chain Monte Carlo (MCMC) techniques stand out, because they yield asymptotically unbiased conditional realizations. However, standard Markov Chain Monte Carlo (MCMC) methods suffer the curse of dimensionality when refining the discretization. This means that their efficiency decreases rapidly with an increasing number of discretization cells. Several MCMC approaches have been developed such that the MCMC efficiency does not depend on the discretization of the random field. The preconditioned Crank Nicolson Markov Chain Monte Carlo (pCN‐MCMC) and the sequential Gibbs (or block‐Gibbs) sampling are two examples. This paper presents a combination of both approaches with the goal to further reduce the computational costs. Our algorithm, the sequential pCN‐MCMC, will depend on two tuning‐parameters: the correlation parameterof the pCN approach and the block sizeof the sequential Gibbs approach. The original pCN‐MCMC and the Gibbs sampling algorithm are special cases of our method. We present an algorithm that automatically finds the best tuning‐parameter combination (and) during the burn‐in‐phase of the algorithm, thus choosing the best possible hybrid between the two methods. In our test cases, we achieve a speedup factors of 1–5.5 over pCN and of 1–6.5 over Gibbs. Furthermore, we provide the MATLAB implementation of our method as open‐source code.
Protein lysine crotonylation: past, present, perspective
Authors: Jiang Gaoyue , Li Chunxia , Lu Meng , Lu Kefeng , Li Huihui
Published: July 2021

Lysine crotonylation has been discovered in histone and non-histone proteins and found to be involved in diverse diseases and biological processes, such as neuropsychiatric disease, carcinogenesis, spermatogenesis, tissue injury, and inflammation. The unique carbon–carbon π-bond structure indicates that lysine crotonylation may use distinct regulatory mechanisms from the widely studied other types of lysine acylation. In this review, we discussed the regulation of lysine crotonylation by enzymatic and non-enzymatic mechanisms, the recognition of substrate proteins, the physiological functions of lysine crotonylation and its cross-talk with other types of modification. The tools and methods for prediction and detection of lysine crotonylation were also described.
Distinct roles of Fto and Mettl3 in controlling development of the cerebral cortex through transcriptional and translational regulations
Authors: Du Kunzhao , Zhang Zhen , Zeng Zhiwei , Tang Jinling , Lee Trevor , Sun Tao
Published: July 2021

Proper development of the mammalian cerebral cortex relies on precise gene expression regulation, which is controlled by genetic, epigenetic, and epitranscriptomic factors. Here we generate RNA demethylase Fto and methyltransferase Mettl3 cortical-specific conditional knockout mice, and detect severe brain defects caused by Mettl3 deletion but not Fto knockout. Transcriptomic profiles using RNA sequencing indicate that knockout of Mettl3 causes a more dramatic alteration on gene transcription than that of Fto. Interestingly, we conduct ribosome profiling sequencing, and find that knockout of Mettl3 leads to a more severe disruption of translational regulation of mRNAs than deletion of Fto and results in altered translation of crucial genes in cortical radial glial cells and intermediate progenitors. Moreover, Mettl3 deletion causes elevated translation of a significant number of mRNAs, in particular major components in m6A methylation. Our findings indicate distinct functions of Mettl3 and Fto in brain development, and uncover a profound role of Mettl3 in regulating translation of major mRNAs that control proper cortical development.
Antioxidant and food additive BHA prevents TNF cytotoxicity by acting as a direct RIPK1 inhibitor
Authors: Delanghe Tom , Huyghe Jon , Lee Seungheon , Priem Dario , Van Coillie Samya , Gilbert Barbara , Choi Sze Men , Vandenabeele Peter , Degterev Alexei , Cuny Gregory D. , Dondelinger Yves , Bertrand Mathieu J. M.
Published: July 2021

Butylate hydroxyanisole (BHA) is a synthetic phenol that is widely utilized as a preservative by the food and cosmetic industries. The antioxidant properties of BHA are also frequently used by scientists to claim the implication of reactive oxygen species (ROS) in various cellular processes, including cell death. We report on the surprising finding that BHA functions as a direct inhibitor of RIPK1, a major signaling hub downstream of several immune receptors. Our in silico analysis predicts binding of 3-BHA, but not 2-BHA, to RIPK1 in an inactive DLG-out/Glu-out conformation, similar to the binding of the type III inhibitor Nec-1s to RIPK1. This predicted superior inhibitory capacity of 3-BHA over 2-BHA was confirmed in cells and using in vitro kinase assays. We demonstrate that the reported protective effect of BHA against tumor necrosis factor (TNF)-induced necroptotic death does not originate from ROS scavenging but instead from direct RIPK1 enzymatic inhibition, a finding that most probably extends to other reported effects of BHA. Accordingly, we show that BHA not only protects cells against RIPK1-mediated necroptosis but also against RIPK1 kinase-dependent apoptosis. We found that BHA treatment completely inhibits basal and induced RIPK1 enzymatic activity in cells, monitored at the level of TNFR1 complex I under apoptotic conditions or in the cytosol under necroptosis. Finally, we show that oral administration of BHA protects mice from RIPK1 kinase-dependent lethality caused by TNF injection, a model of systemic inflammatory response syndrome. In conclusion, our results demonstrate that BHA can no longer be used as a strict antioxidant and that new functions of RIPK1 may emerge from previously reported effects of BHA.
Evolving treatment paradigms for PCV
Authors: Fenner Beau J. , Cheung Chui Ming Gemmy , Sim Shaun S. , Lee Won Ki , Staurenghi Giovanni , Lai Timothy Y. Y. , Ruamviboonsuk Paisan , Kokame Gregg , Yanagi Yasuo , Teo Kelvin Y. C.
Published: July 2021

Polypoidal choroidal vasculopathy (PCV) is a subtype of neovascular AMD (nAMD) that accounts for a significant proportion of nAMD cases worldwide, and particularly in Asia. Contemporary PCV treatment strategies have closely followed those used in typical nAMD, though there are significant gaps in knowledge on PCV management and it remains unclear if these strategies are appropriate. Current clinical trial data suggest intravitreal anti-vascular endothelial growth factor (VEGF) therapy alone or in combination with photodynamic therapy is effective in managing haemorrhage and exudation in PCV, although the optimal treatment interval, including as-needed and treat-and-extend approaches, is unclear. Newer imaging modalities, including OCT angiography and high-resolution spectral domain OCT have enabled characterisation of unique PCV biomarkers that may provide guidance on how and when treatment and re-treatment should be initiated. Treatment burden for PCV is a major focus of future therapeutic research and several newly developed anti-VEGF agents, including brolucizumab, faricimab, and new modes of drug delivery like the port delivery system, offer hope for dramatically reduced treatment burden for PCV patients. Beyond anti-VEGF therapy, recent developments in our understanding of PCV pathophysiology, in particular the role of choroidal anatomy and lipid mediators in PCV pathogenesis, offer new treatment avenues that may become clinically relevant in the future. This article explores the current management of PCV and more recent approaches to PCV treatment based on an improved understanding of this unique disease process.