bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence of Regionally Distributed Tectono‐Volcanism in a Floor Fractured Crater of North‐Central Arabia Terra, Mars
Authors: Rani A. , Basu Sarbadhikari A. , Sinha R. K. , Karunatillake S. , Komatsu G. , Bates A.
Published: October 2021

Arabia Terra features many tectonic structures, which have been correlated to episodes of incipient tectonics, massive impacts, and controls on fluvial systems. However, the extent of regionally distributed tectono‐volcanism and its effects on local structures remains unknown. To characterize the prevalence of volcanically driven processes in this region, we investigate the geomorphic features of an unnamed ∼85‐km diameter and 3.6 Ga old floor‐fractured crater (FFC) in North‐Central Arabia Terra. Widespread crater floor rocks resemble layered sedimentary deposits. Nevertheless, the central crater floor hosts mounds and linear ridges, which have higher thermal inertia than the surroundings, indicating a provenance distinct from the sedimentary units. Crosscutting relationships suggest that the mounds and ridges are stratigraphically overlying the layered sedimentary rocks. Morphologically and morphometrically, the mounds and ridges resemble known Martian and terrestrial volcanic cone and dike systems. Unlike other FFCs of Arabia Terra, the dikes and cone azimuths consistently orient in the NW‐SE direction, implying that regional tectonic controls on their formation overrode localized effects of the crater‐forming impact. Our observations collectively support magma intruding and erupting along regionally controlled tectonic structures; the migration of magma was perhaps facilitated by the impact that formed the host crater. Consequently, the studied FFC may represent a category of hitherto unrecognized numerous, small‐scale volcanic centers controlled by regional tectono‐volcanism within Arabia Terra. This is also consistent with regionally distributed magmatic systems in the late Noachian to early Hesperian, associated with a thermally eroded crust.
Propagation Mechanism of Medium Wave Broadcasting Waves Observed by the Arase Satellite: Hectometric Line Spectra
Authors: Hashimoto Kozo , Shinbori Atsuki , Otsuka Yuichi , Tsuchiya Fuminori , Kumamoto Atsushi , Kasahara Yoshiya , Matsuoka Ayako , Nagano Isamu , Miyoshi Yoshizumi , Yokoyama Tatsuhiro
Published: October 2021

A new type of terrestrial line spectra found by the Arase satellite was reported in 2018. These spectra are called “hectometric line spectra (HLS)”. They primarily consist of constant frequency narrowband components at frequencies between 525 kHz and 1,700 kHz, which originate and are sometimes amplified from AM broadcasting waves. In addition to these, other generated emissions are observed. Entrances and the mode conversion of the AM broadcasting waves into the equatorial and low‐latitude ionosphere with plasma density depletion called plasma bubbles are observed. Electron density profiles and equatorial plasma bubbles are examined through Global Positioning System (GPS)‐Total electron content (TEC) analyses. As a result, the Arase satellite which observed the HLS passed through the TEC depression region near the equatorial ionosphere associated with plasma bubbles. The scenario based on the mode conversion of the L‐O mode to the Z mode and vice versa was confirmed with observations and GPS‐TEC analyses. Another entrance when foF2 estimated from TEC is lower than 1,000 kHz instead of a plasma bubble is also found. No mode conversion is necessary, then.
Study on the Sensitivity of Initial Perturbations to the Development of a Vortex Observed in Southwest China
Authors: Chen Gong , Wang Bin , Liu Juanjuan
Published: October 2021

In this study, numerical experiments on the sensitivity of initial perturbations to the development of southwest vortices (SWVs), which are frequently observed in Southwest China, are performed with weather research and forecasting model. Regarding the development of SWVs as a strong nonlinear process, conditional nonlinear optimal perturbation (CNOP) with an adjoint‐free algorithm is used. The sensitivity denotes how and where the perturbations of model variables at the initial time can influence non‐moving SWV enhancement. The CNOPs leading to the strengthening of the SWV observed at 5UTC July 17, 2010 are obtained. Three sensitive areas are identified based on the distribution of the most significant CNOP norms. Two of them are located on the Eastern Tibetan Plateau (TP), and the third one is found in the eastern Sichuan Basin (SCB) near the SWV center. Sensitivity experiments indicate that the strengthening of the SWV is mainly associated with perturbations at the middle level at approximately 500–450 hPa in the eastern part of the TP and below 450–400 hPa in the eastern SCB near the center of the SWV. Furthermore, the potential vorticity (PV) budget, divergence, vorticity, vertical velocity, diabatic heating, and southerly wind are also analyzed in different simulations. The results show that at the initial stage of SWV formation, the diabatic heating term is not the main cause of PV budget differences between simulations; it is the dynamical effect that is the main contributing factor. However, when it comes to the intensification stage, the diabatic heating caused by the release of latent heat of condensation becomes important.
Determining the Lifespan of Hydrothermal Systems Using Thermochronology and Thermal Modeling
Authors: Jess Scott , Enkelmann Eva , Grasby Stephen E. , Fraser Kelley
Published: October 2021

The drive toward lower carbon emissions has led to a rise in global geothermal exploration. Hot springs are key exploration targets as they reflect active advection of thermal fluids derived from heating of meteoric waters circulating through the upper crust. However, establishing the timing of hot spring formation and the longevity of systems remain key knowledge gaps in our understanding of geothermal systems, such as how and when hydrogeologic conditions enable deep groundwater circulation to initiate. In this study, we demonstrate that a combination of multiple low‐temperature thermochronometers and finite element modeling can be used to determine the lifespan of the Canoe River Hot Springs flow system, British Columbia, Canada. Rocks adjacent to the hot spring show evidence of reheating because of thermal fluids, an effect absent in more distant samples. Hydrothermal modeling of both constant and episodic flow scenarios over different timescales highlights that the hot spring likely began flowing between 4 and 6 Ma. This timing of flow onset implies the hot spring’s formation may be linked to partial melting at the base of the crust, associated with nearby volcanic activity that has increased heat flow across the region in the late Cenozoic. These results have significant implications for the exploration of geothermal energy systems and for understanding the conditions required to form hot springs across British Columbia.
Evidence for European presence in the Americas in ad 1021
Authors: Kuitems Margot , Wallace Birgitta L. , Lindsay Charles , Scifo Andrea , Doeve Petra , Jenkins Kevin , Lindauer Susanne , Erdil Pınar , Ledger Paul M. , Forbes Véronique , Vermeeren Caroline , Friedrich Ronny , Dee Michael W.
Published: October 2021

Transatlantic exploration took place centuries before the crossing of Columbus. Physical evidence for early European presence in the Americas can be found in Newfoundland, Canada1,2. However, it has thus far not been possible to determine when this activity took place3–5. Here we provide evidence that the Vikings were present in Newfoundland in ad 1021. We overcome the imprecision of previous age estimates by making use of the cosmic-ray-induced upsurge in atmospheric radiocarbon concentrations in ad 993 (ref. 6). Our new date lays down a marker for European cognisance of the Americas, and represents the first known point at which humans encircled the globe. It also provides a definitive tie point for future research into the initial consequences of transatlantic activity, such as the transference of knowledge, and the potential exchange of genetic information, biota and pathologies7,8.
Impact of the day of the week on the discontinuation of broad-spectrum antibiotic prescriptions; a multi-centered observational study
Authors: Honda Hiroyuki , Hagiya Hideharu , Higashionna Tsukasa , Haruki Yuto , Haruki Mai , Kajita Shiho , Mukuda Kengo , Yokoyama Yuji , Nakano Yasuhiro , Ogawa Hiroko , Morimoto Yasuyo , Hanayama Yoshihisa , Kanda Setsuko , Kataoka Hitomi , Muguruma Hitomi , Otsuka Fumio
Published: October 2021

To encourage and guide antimicrobial stewardship team (AST) activity and promote appropriate antibiotic use, we studied the impact of day of the week on the initiation and discontinuation of antibiotic administration. This was a multicenter observational study conducted at 8 Japanese hospitals from April 1 to September 30, 2019, targeting patients who underwent treatment with broad-spectrum antibiotics, such as anti-methicillin-resistant Staphylococcus aureus agents and anti-pseudomonal agents. We compared the weekly numbers of initiations and discontinuations of antibiotic prescription on each day of the week or on the days after a holiday. There was no statistical difference in the number of antibiotic initiations on both weekdays and the day after a holiday. However, antibiotic discontinuation was significantly higher from Tuesday onward than Monday and from the second day than the first day after a holiday. Similar trends were observed regardless of the categories of antibiotics, hospital and admission ward, and AST activity. This study suggests that broad-spectrum antibiotics tend to be continued during weekends and holidays and are most likely to be discontinued on Tuesday or the second day after a holiday. This was probably due to behavioral factors beyond medical indications, requiring further antimicrobial stewardship efforts in the future.
Rather than inducing psychological reactance, requiring vaccination strengthens intentions to vaccinate in US populations
Authors: Albarracin Dolores , Jung Haesung , Song Wen , Tan Andy , Fishman Jessica
Published: October 2021

In a survey and three experiments (one preregistered with a nationally representative sample), we examined if vaccination requirements are likely to backfire, as commonly feared. We investigated if relative to encouraging free choice in vaccination, requiring a vaccine weakens or strengthens vaccination intentions, both in general and among individuals with a predisposition to experience psychological reactance. In the four studies, compared to free choice, requirements strengthened vaccination intentions across racial and ethnic groups, across studies, and across levels of trait psychological reactance. The results consistently suggest that fears of a backlash against vaccine mandates may be unfounded and that requirements will promote COVID-19 vaccine uptake in the United States.
Creation of X-linked Alport syndrome rat model with Col4a5 deficiency
Authors: Namba Masumi , Kobayashi Tomoe , Kohno Mayumi , Koyano Takayuki , Hirose Takuo , Fukushima Masaki , Matsuyama Makoto
Published: October 2021

Alport syndrome is an inherited chronic human kidney disease, characterized by glomerular basement membrane abnormalities. This disease is caused by mutations in COL4A3, COL4A4, or COL4A5 gene. The knockout mice for Col4α3, Col4α4, and Col4α5 are developed and well characterized for the study of Alport syndrome. However, disease progression and effects of pharmacological therapy depend on the genetic variability. This model was reliable only to mouse. In this study, we created a novel Alport syndrome rat model utilizing the rGONAD technology, which generated rat with a deletion of the Col4α5 gene. Col4α5 deficient rats showed hematuria, proteinuria, high levels of BUN, Cre, and then died at 18 to 28 weeks of age (Hemizygous mutant males). Histological and ultrastructural analyses displayed the abnormalities including parietal cell hyperplasia, mesangial sclerosis, and interstitial fibrosis. Then, we demonstrated that α3/α4/α5 (IV) and α5/α5/α6 (IV) chains of type IV collagen disrupted in Col4α5 deficient rats. Thus, Col4α5 mutant rat is a reliable candidate for the Alport syndrome model for underlying the mechanism of kidney diseases and further identifying potential therapeutic targets for human renal diseases.
Author Correction: EEG microstate in obstructive sleep apnea patients
Authors: Xiong Xin , Ren Yuyan , Gao Shenghan , Luo Jianhua , Liao Jiangli , Wang Chunwu , Yi Sanli , Liu Ruixiang , Xiang Yan , He Jianfeng
Published: October 2021

The original version of this Article contained an error in Reference 34, which was incorrectly given as:
2-Nitro- and 4-fluorocinnamaldehyde based receptors as naked-eye chemosensors to potential molecular keypad lock
Authors: Islam Muhammad , Shafiq Zahid , Mabood Fazal , Shah Hakikulla H. , Singh Vandita , Khalid Muhammad , de Alcântara Morais Sara Figueirêdo , Braga Ataualpa Albert Carmo , Khan Muhammad Usman , Hussain Javid , Al-Harrasi Ahmed , Marraiki Najat , Zaghloul Nouf S. S.
Published: October 2021

New-generation chemosensors desire small organic molecules that are easy to synthesise and cost-effective. As a new interdisciplinary area of research, the integration of these chemosensors into keypad locks or other advanced communication protocols is becoming increasingly popular. Our lab has developed new chemosensor probes that contain 2-nitro- (1–3) and 4-fluoro-cinnamaldehyde (4–6) and applied them to the anion recognition and sensing process. Probes 1–6 are colorimetric sensors for naked-eye detection of AcO−/CN−/F−, while probes 4–6 could differentiate between F− and AcO−/CN− anions in acetonitrile. Using the density functional theory (DFT), it was found that probes 1–6 acted as effective chemosensors. By using Probe 5 as a chemosensor, we explored colorimetric recognition of multiple anions in more detail. Probe 5 was tested in combination with a combinatorial approach to demonstrate pattern-generation capability and its ability to distinguish among chemical inputs based on concentration. After pattern discrimination using principal component analysis (PCA), we examined anion selectivity using DFT computation. In our study, probe 5 demonstrates excellent performance as a chemosensor and shows promise as a future molecular-level keypad lock system.
Advances in silylation and borylation of fluoroarenes and gem-difluoroalkenes via C–F bond cleavage
Authors: Zhang Juan , Geng Shasha , Feng Zhang
Published: October 2021

Organoboron and organosilane compounds are widely used in organic synthesis and pharmaceuticals.
Charge neutral halogen bonding tetradentate-iodotriazole macrocycles capable of anion recognition and sensing in highly competitive aqueous media
Authors: Bunchuay Thanthapatra , Boonpalit Kajjana , Docker Andrew , Ruengsuk Araya , Tantirungrotechai Jonggol , Sukwattanasinitt Mongkol , Surawatanawong Panida , Beer Paul D.
Published: October 2021

Neutral tetradentate halogen bonding macrocycles bind a range of halide and dicarboxylate anion species in up to 40% water by volume containing aqueous-organic solvent media
Force-induced strengthening of a mechanochromic polymer based on a naphthalene-fused cyclobutane mechanophore
Authors: Wang Taisheng , Wang Haoxiang , Shen Lei , Zhang Na
Published: October 2021

We discovered a force-induced strengthening of a mechanochromic polymer based on a naphthalene-fused cyclobutane mechanophore (NCD).
Prediction of 2D ferromagnetism and monovalent europium ions in EuBr/graphene heterojunctions
Authors: Tan Haoyi , Shan Guangcun , Pacchioni Gianfranco
Published: October 2021

Based on density functional theory calculations, 2D EuBr/graphene heterojunctions are predicted to exhibit metallicity, huge intrinsic-ferromagnetism nearly 7.0 μB per Eu and the special monovalent Eu ions, where EuBr plays an important role.
Ultrafast photoelectron spectroscopy of photoexcited aqueous ferrioxalate
Authors: Longetti L. , Barillot T. R. , Puppin M. , Ojeda J. , Poletto L. , van Mourik F. , Arrell C. A. , Chergui M.
Published: October 2021

The photochemistry of metal–organic compounds in solution is determined by both intra- and inter-molecular relaxation processes after photoexcitation.
Attomolar analyte sensing techniques (AttoSens): a review on a decade of progress on chemical and biosensing nanoplatforms
Authors: Usha Sruthi Prasood , Manoharan Hariharan , Deshmukh Rehan , Álvarez-Diduk Ruslan , Calucho Enric , Sai V. V. R. , Merkoçi Arben
Published: October 2021

Attomolar analyte sensing in clinical diagnosis, food safety and environmental monitoring achieved by the technological advances in transducers design, bioreceptors functionalization and nanomaterials synthesis.
Tetranuclear ruthenium clusters anchored on polyoxometalates catalyze the hydrogenation of methyl levulinate in water
Authors: Wang Jiajia , Qiao Wencheng , Zhao Xiuge , Chen Manyu , Peng Qingpo , Cui Kai , Wei Xinjia , Yao Yefeng , Hou Zhenshan
Published: October 2021

The tungstoaluminate-anchored ruthenium cluster catalyst is efficient and recyclable for the selective hydrogenation of methyl levulinate (ML) to gamma-valerolactone or methyl 4-hydroxypentanoate.
Beyond conventional construction of the phthalimide core: a review
Authors: Das Suven
Published: October 2021

This review highlights (2010–2021) different strategies for the construction of the phthalimide core apart from traditional synthetic routes.
A NaX zeolite framework containing magnetic MgFe2O4/CdO nanoparticles: synthesis, characterization and catalytic performance in the decontamination of 2-chloroethyl phenyl sulfide (2-CEPS) as a model of sulfur mustard agent
Authors: Sadeghi Meysam , Farhadi Saeed , Zabardasti Abedin
Published: October 2021

Magnetic MgFe2O4/CdO nanoparticles were immobilized in a zeolite NaX network and their application for the decontamination of sulfur mustard agent simulant 2-CEPS was evaluated.
Room-temperature blue-light-emitting liquid crystalline materials based on phenanthroimidazole-substituted carbazole derivatives
Authors: Sharma Vinay S. , Sharma Anuj S. , Ganga Venkata Subba Rao , Shrivastav Pranav S. , Shah Priyanka A. , Agarwal Nikhil
Published: October 2021

We report disc-shaped materials with the A–Π–D molecular architecture based on the phenanthroimidazole-linked carbazole group as blue-light-emitting materials with room-temperature liquid crystalline properties.
Anthraquinone-fused enediynes: discovery, biosynthesis and development
Authors: Yan Xiaohui
Published: October 2021

This review summarizes the research on the anthraquinone-fused enediynes, a small group of microbial natural products with phenomenal cytotoxicity, including their discovery, mode of action, biosynthesis, total synthesis and clinical development.
Bewegungsförderung für Bewohner in Pflegeheimen
Authors: Krupp Sonja , Wentzel Robert , Nachtsheim Martina , Höhne Bettina , Kasper Jennifer
Published: October 2021

Ältere Menschen zeigen nach Aufnahme in eine Einrichtung der stationären Pflege oft eine Reduktion ihres Bewegungsverhaltens mit konsekutiver weiterer Verschlechterung der Mobilität und Selbstversorgungsfähigkeiten. Das Präventionsgesetz beinhaltet den Auftrag, auch in der Lebenswelt Pflegeheim unter Einbezug der Wünsche der Senioren nach Möglichkeiten zu suchen, über eine Zunahme der bewegungsassoziierten Aktivitäten eine Verbesserung der weiteren Prognose und Lebensqualität zu erreichen. POLKA setzt in zweifacher Hinsicht auf Kombinationen: Es bietet sowohl Gesundheitsförderung für das in Pflegeheimen tätige Personal als auch die Bewohner an und erhöht die Kompetenz des Personals in Sachen Bewegungsförderung durch das Tandem aus fest im Pflegeteam verankerten Bewegungsexperten und einem noch umfassender qualifizierten Bewegungslotsen. Die Tätigkeit als Bewegungsexperte bietet die Möglichkeit, täglich als Sachverständiger in Sachen Bewegungsförderung zu fungieren, aber auch die, sich zweimal wöchentlich selbst beraten zu lassen bzw. gemeinsam mit dem Bewegungslotsen relevante Bewegungs-Ziele der Bewohner zu verfolgen. Damit die Auswahl der Ziele und der Wege, diese zu erreichen, zu den realen Möglichkeiten der pflegebedürftigen Person passen, bedarf es eines geriatrischen Assessments. Der Bewegungslotse beherrscht dieses vollumfänglich, der Bewegungsexperte und andere im Pflegeteam erlernen zwei Instrumente, deren Anwendung ihnen hilft, Bewegungsförderung systematisch durchzuführen. Als Interventionen stehen u. a. drei verschiedene Formate des von der Forschungsgruppe Geriatrie Lübeck entwickelten Trainings in „Bewegungswelten“ zur Verfügung.
4-Alkyl-3-azidomethyl-2-ethoxy-2,5-dihydro-5H-1,2-oxaphosphole 2-Oxides: Synthesis and 1,3-Cycloaddition
Authors: Brel Valery K. , Alekseychuk Ekaterina P. , Artyushin Oleg I. , Anikina Lada V.
Published: October 2021

Starting from phosphorylated allenes, a three-steps synthesis of a new class of organic azides with a 1,2-oxaphospholene carbon skeleton has been developed. The series of obtained 4-alkyl-3-azidomethyl-2-ethoxy-2,5-dihydro-5H-1,2-oxaphosphole 2-oxides were utilized in the 1,3-cycloaddition with alkyl 2-[1-(propyn-2-yl)-1H-indol-3-yl]-2-oxoacetates for the synthesis of conjugates, which are potentially active cytostatics.
An efficient continuous data assimilation algorithm for the Sabra shell model of turbulence
Authors: Chen Nan , Li Yuchen , Lunasin Evelyn
Published: October 2021

Complex nonlinear turbulent dynamical systems are ubiquitous in many areas of research. Recovering unobserved state variables is an important topic for the data assimilation of turbulent systems. In this article, an efficient continuous-in-time data assimilation scheme is developed, which exploits closed analytic formulas for updating the unobserved state variables. Therefore, it is computationally efficient and accurate. The new data assimilation scheme is combined with a simple reduced order modeling technique that involves a cheap closure approximation and noise inflation. In such a way, many complicated turbulent dynamical systems can satisfy the requirements of the mathematical structures for the proposed efficient data assimilation scheme. The new data assimilation scheme is then applied to the Sabra shell model, which is a conceptual model for nonlinear turbulence. The goal is to recover the unobserved shell velocities across different spatial scales. It is shown that the new data assimilation scheme is skillful in capturing the nonlinear features of turbulence including the intermittency and extreme events in both the chaotic and the turbulent dynamical regimes. It is also shown that the new data assimilation scheme is more accurate and computationally cheaper than the standard ensemble Kalman filter and nudging data assimilation schemes for assimilating the Sabra shell model with partial observations.
Koopman spectral analysis of elementary cellular automata
Authors: Taga Keisuke , Kato Yuzuru , Kawahara Yoshinobu , Yamazaki Yoshihiro , Nakao Hiroya
Published: October 2021

We perform a Koopman spectral analysis of elementary cellular automata (ECA). By lifting the system dynamics using a one-hot representation of the system state, we derive a matrix representation of the Koopman operator as the transpose of the adjacency matrix of the state-transition network. The Koopman eigenvalues are either zero or on the unit circle in the complex plane, and the associated Koopman eigenfunctions can be explicitly constructed. From the Koopman eigenvalues, we can judge the reversibility, determine the number of connected components in the state-transition network, evaluate the period of asymptotic orbits, and derive the conserved quantities for each system. We numerically calculate the Koopman eigenvalues of all rules of ECA on a one-dimensional lattice of 13 cells with periodic boundary conditions. It is shown that the spectral properties of the Koopman operator reflect Wolfram’s classification of ECA.
Constructing spin pathways in LaCoO3 by Mn substitution to promote oxygen evolution reaction
Authors: Cao Yuan , Gao Linfeng , Lai Zhenhai , Wang Cheng , Yao Yingfang , Zhu Xi , Zou Zhigang
Published: October 2021

Designing efficient oxygen evolution reaction (OER) electrocatalysts is essential for numerous sustainable energy conversion technologies. An obstacle that impedes the development of OER electrocatalysts is the insufficient emphasis on the spin attribution of electrons. Recently, the different spin configuration of reactants and products in the OER has been recognized as the factor that slows down the reaction kinetics. In this work, Mn substitution was introduced to LaCoO3, which brought about lattice expansion and reduced crystalline field splitting energy. This led to the increase in the effective magnetic moment, which triggers the transfer of Co3+ from low to higher spin states. Thus, the hybridization of Co eg and O 2p states across the Fermi level was strengthened. Specifically, with 25 at. % Mn substitution, LaCoO3 transits from a semiconductor to a half-metal, which benefits the spin-oriented electronic transport and resultantly promotes the OER. This method paves the way for the construction of spin pathways in catalysts.
“Zyflex”: Next generation plasma chamber for complex plasma research in space
Authors: Knapek C. A. , Konopka U. , Mohr D. P. , Huber P. , Lipaev A. M. , Thomas H. M.
Published: October 2021

In this paper, we give a detailed description of a novel plasma chamber—the Zyflex chamber—that has been specifically designed for complex/dusty plasma research under reduced gravitational influence as realized during parabolic flight or aboard the International Space Station. The cylindrical, radio-frequency driven discharge device includes a variety of innovations that, for example, allow us to flexibly adjust plasma parameters and its volume via enhanced plasma generation control and a movable, multi-segmented electrode system. The new complex/dusty plasma research tool also supports, due to its overall increased size compared to former space based complex plasma experiments such as PKE-Nefedov or PK-3 Plus, much larger particle systems. Additionally, it can be operated at much lower neutral gas pressures, thus reducing the damping of particle motion considerably. Beyond the technical description and particle-in-cell simulation based characterization of the plasma vessel, we show sample results from experiments performed with this device in the laboratory as well as during parabolic flights, both of which clearly demonstrate the new quality of complex/dusty plasma research that becomes accessible with this new plasma device.
A unified multi-phase and multi-material formulation for combustion modeling
Authors: Nikodemou M. , Michael L. , Nikiforakis N.
Published: October 2021

The motivation of this work is to produce an integrated formulation for material response (e.g., elastoplastic, viscous, viscoplastic) due to detonation wave loading. Here, we focus on elastoplastic structural response. In particular, we want to capture miscible and immiscible behavior within condensed-phase explosives arising from the co-existence of a reactive carrier mixture of miscible materials and several material interfaces due to the presence of immiscible impurities such as particles or cavities. The dynamic and thermodynamic evolution of the explosive is communicated to one or more inert confiners through their shared interfaces, which may undergo severe topological change. We also wish to consider elastic and plastic structural response of the confiners rather than make a hydrodynamic assumption for their behavior. The previous work by these authors has met these requirements by means of the simultaneous solution of appropriate systems of equations for the behavior of the condensed-phase explosive and the elastoplastic behavior of the confiners. To that end, both systems were written in the same mathematical form as a system of inhomogeneous hyperbolic partial differential equations (PDEs), which were solved on the same discrete space using the same algorithms, as opposed to coupling fluid and solid algorithms (co-simulation). In the present work, we employ a single system of PDEs proposed by Peshkov and Romenski [Peshkov and Romenski, “A hyperbolic model for viscous Newtonian flows,” Continuum Mech. Thermodyn. 28, 85 (2016)], which is able to account for different states of matter by means of generalizing the concept of distortion tensors beyond solids. We amalgamate that formulation with a single system of PDEs, which meets the requirement of co-existing miscible and immiscible explosive mixtures. We present the mathematical derivation and construct appropriate algorithms for its solution. The resulting model is validated against exact solutions for several one-dimensional use-cases, including mechanically and thermally induced, inviscid, and viscous detonations. Results indicate that the model can accurately simulate a very broad range of problems involving the nonlinear interaction between reactive and inert materials within a single framework.
The function of the alula with different geometric parameters on the flapping wing
Authors: Bao Han , Song Bifeng , Yang Wenqing , Xue Dong
Published: October 2021

Birds in nature have the ability to maintain high aerodynamic efficiency in complex flight conditions. This agility stems from the multi-degree-of-freedom flapping motion and specialized feather systems that evolved over millions of years. The leading-edge alula is considered a typical feather system that can enhance the flight envelope and capabilities of birds at low speed and high incidence. Previous studies usually adopted a static model, ignoring unsteady effects caused by flapping motion. Thus, we numerically investigated the function of the alula with different geometric parameters on the flapping wing in this paper. The alula has both the slot effect and vortex generator effect during the flapping motion, whereas the effect that plays a main role in lift enhancement changes as time varies. At the beginning of the upstroke, the slot effect plays the main role. At mid-time of the upstroke, the vortex generator effect plays the main role. Different geometric parameters have different influences on these two effects. The dimensionless spanwise location affects the strength of both the ATEV (alula trailing edge vortex) and ASV (alula streamwise vortex). The relative angle affects mainly the strength of the ATEV, whereas the deflection angle affects mainly the strength of the ASV. The optimal geometric parameters to obtain maximum lift enhancement are a dimensionless spanwise location of 0.5, a relative angle of 0°, and a deflection angle of 10°, with a lift enhancement of 5.5% compared to the baseline wing.
Nuclear relaxation rate enhancement by a 14N quadrupole nucleus in a fluctuating electric-field gradient
Authors: Belorizky Elie , Fries Pascal H.
Published: October 2021

We consider the longitudinal quadrupole relaxation rate enhancement (QRE) of a 1H nucleus due to the time fluctuations of the local dipolar magnetic field created by a close quadrupole 14N nucleus, the electric-field gradient (EFG) Hamiltonian of which changes with time because of vibrations/distortions of its chemical environment. The QRE is analytically expressed as a linear combination of the cosine Fourier transforms of the three quantum time auto-correlation functions GAA(t) of the 14N spin components along the principal axes A = X, Y, and Z of the mean (time-averaged) EFG Hamiltonian. Denoting the three transition frequencies between the energy levels of this mean Hamiltonian by νA, the functions GAA(t) oscillate at frequencies νA + sA/(2π) with mono-exponential decays of relaxation times τA, where the frequency dynamic shifts sA and the relaxation times τA are closed expressions of the magnitude of the fluctuations of the instantaneous EFG Hamiltonian about its mean and of the characteristic fluctuation time. Thus, the theoretical QRE is the sum of three Lorentzian peaks centered at νA + sA/(2π) with full widths at half maxima 1/(πτA). The predicted peak widths are nearly equal. The predicted dynamic shifts of the peaks are much smaller than their widths and amazingly keep proportional to the transition frequencies νA for reasonably fast EFG fluctuations. The theory is further improved by correcting the transition frequencies by the 14N Zeeman effects of second order. It is successfully applied to reinterpret the QRE pattern measured by Broche, Ashcroft, and Lurie [Magn. Reson. Med. 68, 358 (2012)] in normal cartilage.
Surface-facilitated trapping by active sites: From catalysts to viruses
Authors: Misiura Mikita M. , Berezhkovskii Alexander M. , Bezrukov Sergey M. , Kolomeisky Anatoly B.
Published: October 2021

Trapping by active sites on surfaces plays important roles in various chemical and biological processes, including catalysis, enzymatic reactions, and viral entry into host cells. However, the mechanisms of these processes remain not well understood, mostly because the existing theoretical descriptions are not fully accounting for the role of the surfaces. Here, we present a theoretical investigation on the dynamics of surface-assisted trapping by specific active sites. In our model, a diffusing particle can occasionally reversibly bind to the surface and diffuse on it before reaching the final target site. An approximate theoretical framework is developed, and its predictions are tested by Brownian dynamics computer simulations. It is found that the surface diffusion can be crucial in mediating trapping by active sites. Our theoretical predictions work reasonably well as long as the area of the active site is much smaller than the overall surface area. Potential applications of our approach are discussed.
Prospects for n-type conductivity in cubic boron nitride
Authors: Turiansky Mark E. , Wickramaratne Darshana , Lyons John L. , Van de Walle Chris G.
Published: October 2021

Cubic boron nitride is an ultrawide-bandgap semiconductor with potential applications in high-power electronics, ultraviolet optoelectronics, and quantum information science. Many of those applications are predicated on the ability to control doping. Using hybrid-functional first-principles calculations, we systematically explore potential donors including group-IV (C, Si, and Ge) and group-VI (O, S, and Se) elements, as well as Li and F. We also address the role of compensation either by substitution on the wrong site or due to native point defects. We identify SiB and ON as promising dopants, as they have the lowest formation energies and do not suffer from self-compensation. However, compensation by boron vacancies, which act as deep acceptors, poses a challenge. We discuss strategies to mitigate these effects.
Topological magnetic textures and long-range orders in terbium-based quasicrystal and approximant
Authors: Watanabe Shinji
Published: October 2021

Significance

So far, the lack of microscopic theory for the crystalline electric field (CEF) in the rare earth–based quasicrystal has prevented us from understanding the magnetic property. Our full analysis of the CEF in the Tb-based quasicrystal has made it possible to clarify that magnetic anisotropy arising from the CEF gives rise to unique magnetic textures on the icosahedron, which are characterized by the topological charges. This is a discovery of the topological magnetic textures in the quasicrystal and also, in the approximant crystal. The ferromagnetic long-range order is theoretically found to be realized in the quasicrystal. Our proposed model is effective for understanding the topological as well as magnetic properties in the rare earth–based quasicrystal and approximant crystal.
Physician Trainees’ Compassion Satisfaction, Burnout, and Self-Efficacy When Caring for People who Inject Drugs
Authors: Jawa Raagini , Laks Jordana , Saravanan Nivetha , Demers Lindsay , Wishik-Miller Gabriel
Published: October 2021

Background: Front-line providers working with people who inject drugs (PWID) are at increased risk of experiencing burnout. Few studies have examined protective factors against burnout incurred in the care of PWID, including harm reduction counseling skills. We measured self-efficacy in harm reduction counseling, burnout, and compassion satisfaction among Internal Medicine (IM) trainees caring for PWID. Methods: In this cross-sectional study, we surveyed IM interns and residents. Self-efficacy was assessed by asking trainees about attitudes, comfort, and knowledge in harm reduction counseling on a five-point Likert scale. Burnout and compassion satisfaction were assessed via an adapted 20-question Professional Quality of Life Scale. We compared self-efficacy in harm reduction counseling, compassion satisfaction, and burnout between interns and residents using ANOVA and Mann–Whitney U tests. We used Spearman's rho correlational analysis to examine the relationship between these three variables. Results: Seventy-nine IM trainees (36 interns, 43 residents) completed the survey for a 52% response rate. Residents reported higher self-efficacy in harm reduction counseling, similar levels of burnout, and higher compassion satisfaction compared to interns. Across training levels, we found a negative correlation between burnout and compassion satisfaction ( r = −0.55, p < 0.01) and a positive correlation between compassion satisfaction and comfort counseling PWID on harm reduction ( r = 0.30, p < 0.01). Conclusions: Among IM trainees at an urban institution serving a large population of PWID, self-efficacy in harm reduction counseling and compassion satisfaction increase with time in training while burnout remains similar. Strengthening trainees’ capacity to counsel PWID on harm reduction may improve their compassion satisfaction in caring for this population, potentially leading to improved care. This relationship should be explored longitudinally in larger cohorts and through evaluations of harm reduction-focused medical education.
Ego orientation is related to doping likelihood via sport supplement use and sport supplement beliefs
Authors: Hurst Philip , Ring Christopher , Kavussanu Maria
Published: October 2021

A growing body of evidence suggests sport supplement use is positively related to doping likelihood, both directly and indirectly via beliefs that sport supplements are effective for improving performance. However, it is unclear what leads an athlete to use sport supplements and whether such factors play a role in the supplement‐beliefs‐doping relationship. To address this issue, we examined whether motivational goal orientations were related to doping likelihood directly and indirectly via sport supplement use and sport supplement beliefs. Competitive athletes (N = 362, 39% female, mean ± SD; age = 23.6 ± 10.3 years, hours per week training = 5.8 ± 2.1, years competing = 5.8 ± 5.4) from a range of sports (e.g. athletics, soccer, weightlifting) completed an online survey measuring task and ego goal orientation, sport supplement use, sport supplement beliefs, and doping likelihood. Results indicated that ego orientation, but not task orientation, was indirectly related to doping likelihood via sport supplement use and sport supplement beliefs. This suggests that athletes who are ego oriented are more likely to use supplements, believe supplements are effective, and dope. These data suggest that researchers should consider ego goal orientations when interpreting relationships between sport supplement use and doping likelihood.

Highlights

Ego orientation is related to doping likelihood via sport supplement use and beliefs.

Task orientation is not related to doping likelihood via sport supplement use and beliefs.

Ego‐orientated athletes using sport supplements may be more likely to dope.

Researchers should consider ego goal orientation when interpreting relationships between sport supplement use and doping likelihood.
ATG8ylation of proteins: A way to cope with cell stress?
Authors: Carosi Julian M. , Nguyen Thanh N. , Lazarou Michael , Kumar Sharad , Sargeant Timothy J.
Published: October 2021

The ATG8 family of proteins regulates autophagy in a variety of ways. Recently, ATG8s were demonstrated to conjugate directly to cellular proteins in a process termed “ATG8ylation,” which is amplified by mitochondrial damage and antagonized by ATG4 proteases. ATG8s may have an emerging role as small protein modifiers.
Suppression of leakage current of p-GaN gate AlGaN/GaN HEMTs with beta-Ga2O3 back barrier
Authors: Ge Mei , Li Yi , Zhu Youhua , Chen Dunjun , Wang Zhiliang , Tan Shuxin
Published: October 2021

This research demonstrates a p-GaN gate AlGaN/GaN high electron mobility transistor with beta-Ga2O3 back barrier and investigates the electric characteristics of the device. The simulated results show that the threshold voltage of the device will increase with the use of the Ga2O3 back barrier. Moreover, the off-state leakage current level is one order of magnitude lower than the device without back barrier, which can be attributed to the rise of the conduction band diagram in the buffer layer and the decrease of the electron current density released by ionized accept traps. In addition, the impacts of the beta-Ga2O3 back barrier thickness are investigated, and the results show that with increasing Ga2O3 thicknesses, the threshold voltage of the device decreases while the leakage current of the device increases.
Secondary neutron dose contribution from pencil beam scanning, scattered and spatially fractionated proton therapy
Authors: Leite A M M , Ronga M G , Giorgi M , Ristic Y , Perrot Y , Trompier F , Prezado Y , Créhange G , De Marzi L
Published: October 2021

The Orsay Proton therapy Center (ICPO) has a long history of intracranial radiotherapy using both double scattering (DS) and pencil beam scanning (PBS) techniques, and is actively investigating a promising modality of spatially fractionated radiotherapy using proton minibeams (pMBRT). This work provides a comprehensive comparison of the organ-specific secondary neutron dose due to each of these treatment modalities, assessed using Monte Carlo (MC) algorithms and measurements. A MC model of a universal nozzle was benchmarked by comparing the neutron ambient dose equivalent, H*(10), in the gantry room with measurements obtained using a WENDI-II counter. The secondary neutron dose was evaluated for clinically relevant intracranial treatments of patients of different ages, in which secondary neutron doses were scored in anthropomorphic phantoms merged with the patients’ images. The MC calculated H*(10) values showed a reasonable agreement with the measurements and followed the expected tendency, in which PBS yields the lowest dose, followed by pMBRT and DS. Our results for intracranial treatments show that pMBRT yielded a higher secondary neutron dose for organs closer to the target volume, while organs situated furthest from the target volume received a greater quantity of neutrons from the passive scattering beam line. To the best of our knowledge, this is the first study to compare MC secondary neutron dose estimates in clinical treatments between these various proton therapy modalities and to realistically quantify the secondary neutron dose contribution of clinical pMBRT treatments. The method established in this study will enable epidemiological studies of the long-term effects of intracranial treatments at ICPO, notably radiation-induced second malignancies.
Parametrization, structure and Bruhat order of certain spherical quotients
Authors: Chaput Pierre-Emmanuel , Fresse Lucas , Gobet Thomas
Published: October 2021

Let

G
G

be a reductive algebraic group and let

Z
Z

be the stabilizer of a nilpotent element

e
e

of the Lie algebra of

G
G

. We consider the action of

Z
Z

on the flag variety of

G
G

, and we focus on the case where this action has a finite number of orbits (i.e.,

Z
Z

is a spherical subgroup). This holds for instance if

e
e

has height

2
2

. In this case we give a parametrization of the

Z
Z

-orbits and we show that each

Z
Z

-orbit has a structure of algebraic affine bundle. In particular, in type

A
A

, we deduce that each orbit has a natural cell decomposition. In the aim to study the (strong) Bruhat order of the orbits, we define an abstract partial order on certain quotients associated to a Coxeter system. In type

A
A

, we show that the Bruhat order of the

Z
Z

-orbits can be described in this way.
Winners and Losers: the Distributional Effects of the French Feebate on the Automobile Market
Authors: Durrmeyer Isis
Published: October 2021

I quantify the welfare and environmental gains and losses from a policy establishing an environmental tax/subsidy for new cars in France in 2008. I estimate a structural model of demand and supply that features heterogeneity in consumer preferences to go beyond the average policy effects and analyse distributional aspects. The policy reduces average carbon emissions by 1.6% at the cost of additional emissions of local pollutants. The regulation favours middle-income individuals but has redistributive effects when combined with a tax that is proportional to income. Moreover, local pollutant emissions increase least in poor and rural areas, suggesting another redistribution channel.
It’s the End of the (Offline) World as We Know It: From Human Rights to Digital Human Rights – A Proposed Typology
Authors: Dror-Shpoliansky Dafna , Shany Yuval
Published: October 2021

‘The same rights that people have offline must also be protected online’ is used in recent years as a dominant concept in international discourse about human rights in cyberspace. But does this notion of ‘normative equivalency’ between the ‘offline’ and the ‘online’ afford effective protection for human rights in the digital age? This is the question at the heart of this article. We first review the development of human rights in cyberspace as they were conceptualized and articulated in international fora and critically evaluate the normative equivalency paradigm adopted by international bodies for the online application of human rights. We then attempt to describe the contours of a new digital human rights framework, which goes beyond the normative equivalency paradigm. We offer in this connection a typology of three ‘generations’ or modalities in the evolution of digital human rights – the radical reinterpretation of existing rights, the development of new rights and the introduction of new right and duty holders. In particular, we focus on the emergence of new digital human rights, present two prototype rights (the right to Internet access and the right not to be subject to automated decision) and discuss the normative justifications invoked for recognizing these new digital human rights. We propose that such a multilayered framework corresponds better than the normative equivalency paradigm to the unique features and challenges of upholding human rights in cyberspace.
Is the Establishment of Air Defence Identification Zones Outside National Airspace in Accordance with International Law?
Authors: Su Jinyuan
Published: October 2021

Whereas the right of a state to establish an air defence identification zone (ADIZ) in national airspace falls squarely within its sovereignty, the question whether coastal states may claim such zones outside national airspace remains a matter of controversy. The latter category, referred to as ‘offshore ADIZs’, usually do not amount to sovereignty claims over the open airspace outside national airspace or involve threat or use of force. The right of coastal states to identify aircraft in the open airspace near coastal areas has arguably become part of customary international law. This customary right, however, only extends to ‘passive identification’ by radar detection, radio communication or close visual checks, which thus is only capable of justifying the establishment of offshore ADIZs for this purpose. The identification of aircraft in offshore ADIZs, through either voluntary or passive measures, is nevertheless within the parameters of the obligation of paying due regard to the freedom of overflight. This explains why ‘passive identification’ is ‘permissible’ under customary international law, while ‘voluntary identification’ is at least ‘tolerated’ albeit in the absence of a permissive customary rule.