bluuebunny/crossref_metadata_2025 huggingface dataset:
Optically induced coherent voltage oscillations in K0.3MoO3
Authors: van Loosdrecht P. H.M. , Beschoten B. , Dotsenko I. , van Smaalen S.
Published: July 2021

Optical induced transient changes of the electrical conductivity are investigated in the
non-linear transport regime of the blue bronze K0.3MoO3 below its Peierls transition using the impulsive infrared
excitation of a free-electron laser a t energies above the Peierls gap. The transients of the sample voltage have
typical relaxation times of 0.5-2 ms superimposed by coherent voltage oscillations, which exhibit lifetimes of
up 100 ms. The frequency of those voltage oscillation is found to be time dependent. This, in comparison
with voltage oscillations purely driven by static electrical fields, enables the study of quasiparticle dynamics
in the charge density condensate of the blue bronze.
Prediction of the kinetics of the phase transformations and the associated microstructure during continuous coolingin the Ti17
Authors: J. Da Costa Teixeira  , Héricher L. , Appolaire B. , Aeby-Gautier E. , Cailletaud G. , Denis S. , Spath N.
Published: July 2021

The aim of this paper is to present recent experimental results and related simulation about the β → αGB + αWGB and → αWI transformations which occur in the Ti17 alloy during the thermal treatments following the heating in the β phase field. These phase transformations were experimentally studied under isothermal conditions in samples with negligible thermal gradients. The IT diagram was obtained, on the basis of electrical resistivity measurements and microstructural SEM observations. The kinetics of the phase transformation was further numerically simulated for continuous cooling on the basis of a formerly developed model giving the amount of each morphology (αWGB, αWI). Experimental and calculated results are compared.
Salivary diagnosis of oral cancers by salivary samples: a systematic literature review
Authors: Guillon Marine , Pham Dang Nathalie , Thévenon Joannice , Devoize Laurent
Published: July 2021

The aim of this article is to carry out a systematic analysis of the literature concerning the diagnosis of oral cancers by salivary samples. Different biomarkers, produced by the tumor itself or by its environment, show significant variations in their concentration at the salivary level, correlated or not at the blood or tissue level. After studying 239 articles, we included 36 in this analysis. This allowed us to extract 46 potential molecules for salivary diagnostics. Only 26 demonstrated a good level of evidence. 8 clusters have also been proposed for better specificity and sensitivity. To date, the protocols of the studies carried out do not allow to affirm that one or more biomarkers are effective for a salivary diagnosis of oral cancers. Part of the results contradict or sometimes lack precision. In addition, the studies included here do not have a good methodological quality and do not always take into account other factors influencing the concentrations (systemic diseases, age, sex, tobacco, alcohol, etc.). Additional studies are still necessary, notably with larger groups of patients, representative of the general population and standardization of the protocols for the study and quantification of biomarkers.
Predicting effectiveness of countermeasures during the COVID-19 outbreak in South Africa using agent-based simulation
Authors: Kersting Moritz , Bossert Andreas , Sörensen Leif , Wacker Benjamin , Schlüter Jan Chr.
Published: July 2021

COVID-19 has spread rapidly around the globe. While there has been a slow down of the spread in some countries, e.g., in China, the African continent is still at the beginning of a potentially wide spread of the virus. Owing to its economic strength and imbalances, South Africa is of particular relevance with regard to the drastic measures to prevent the spread of this novel coronavirus. In March 2020, South Africa imposed one of the most severe lockdowns worldwide and subsequently faced the number of infections slowing down considerably. In May 2020, this lockdown was partially relaxed and further easing of restrictions was envisaged. In July and August 2020, daily new infections peaked and declined subsequently. Lockdown measures were further relaxed. This study aims to assess the recent and upcoming measures from an epidemiological perspective. Agent-based epidemic simulations are used to depict the effects of policy measures on the further course of this epidemic. The results indicate that measures that are either lifted too early or are too lenient have no sufficient mitigating effects on infection rates. Consequently, continuous exponential infection growth rates or a second significant peak of infected people occur. These outcomes are likely to cause higher mortality rates once healthcare capacities are occupied and no longer capable to treat all severely and critically infected COVID-19 patients. In contrast, strict measures appear to be a suitable way to contain the virus. The simulations imply that the initial lockdown of 27 March 2020 was probably sufficient to slow the growth in the number of infections, but relaxing countermeasures might allow for a second severe outbreak of COVID-19 in our investigated simulation region of Nelson Mandela Bay Municipality.
Atomistic origin of compositional pulling effect in wurtzite (B, Al, In)xGa1−xN: A first-principles study
Authors: Mizuseki Hiroshi , Gueriba Jessiel Siaron , Empizo Melvin John F. , Sarukura Nobuhiko , Kawazoe Yoshiyuki , Ohkawa Kazuhiro
Published: July 2021

Some fluctuations in composition are commonly observed in epitaxial-grown III-V multinary alloys. These fluctuations are attributed to compositional pulling effects, and an insight into their atomistic origin is necessary to improve current epitaxial growth techniques. In addition, the crystallinity of III-V multinary alloys varies widely depending on the constituent atoms. Using first-principles calculations, we then investigated different geometric configurations of gallium nitride (GaN)-based ternary alloy, X0.125Ga0.875N where X is the minority atom which is boron (B), aluminum (Al), or indium (In). The minority atoms are presented as two atoms in the simulation cell, and the energetics of five geometric configurations are analyzed to estimate the most stable configuration. For the B0.125Ga0.875N alloy, the most stable configuration is the one where the minority atoms occupy gallium (Ga) sites in a collinear orientation along the c-axis. On the contrary, the configurations along the in-plane direction result in a higher energy state. In0.125Ga0.875N and Al0.125Ga0.875N also show the same trend with a small relative energy difference. These preferential sites of minority atoms are consistent with composition pulling effects in wurtzite nitride phases. Moreover, the degree of crystallinity for wurtzite nitride alloys can be well described by the order of calculated relative energy.
Akhiezer mechanism dominates relaxation of propagons in amorphous material at room temperature
Authors: Liao Yuxuan , Shiomi Junichiro
Published: July 2021

Propagons play an important role in tuning the thermal conductivity of nanostructured amorphous materials. Although advances have been made to quantitatively evaluate the relaxation time of propagons with molecular dynamics, the underlying relaxation mechanism remains unexplored. Here, we investigate the relaxation process of propagons in amorphous silicon, amorphous silica, and amorphous silicon nitride at room temperature in terms of the Akhiezer model, the parameters of which were evaluated by performing lattice dynamics and molecular dynamics analysis. The results show that the Akhiezer model can well reproduce experimental results obtained by various types of measurement methods, indicating that the Akhiezer mechanism dominates the relaxation process of propagons at room temperature. Moreover, we show that the appropriate sound speed of propagons is around 80% of the Debye sound speed and comparable to the transversal sound speed. We also reveal that diffusons’ contribution to thermal conductivity of these amorphous materials is similar, which is around 1 W/m K, whereas propagons’ contribution to the overall heat conduction varies significantly depending on the materials: it is 30% in amorphous silicon and silica but as high as 70% in amorphous silicon nitride. The Akhiezer mechanism offers a deeper understanding of propagon heat transport and sound attenuation in amorphous materials.
A simple model of a strong shock driven by a spherical or cylindrical piston
Authors: Ryutov D. D.
Published: July 2021

A simple model of piston-driven spherical and cylindrical shocks is suggested. The model is based on a consistent use of two factors: (a) an almost uniform pressure across the shocked layer and, (b) continuous geometrical stretching of the surface elements of the expanding piston. It turns out that for a uniform pre-shock medium the gas between the piston and the shock behaves essentially as an incompressible fluid. An algebraic equation for the shock vs piston position is obtained. Detailed evaluation of the accuracy of the proposed solution shows that its accuracy is a few percent for the adiabatic index γ=5/3 (as in ideal plasma). A closed-form solution describing enhancement of a weak ambient magnetic field by the shock is presented. The proposed model of piston-driven shocks goes beyond the classical self-similar solutions in that it: (1) naturally covers an early, non-asymptotic dynamics and its transition to asymptotic regime; (2) allows for smooth radial density variation of an ambient gas of the form of bumps, dimples or ramps between two constant values; and (3) allows for smooth temporal variation of piston velocity of the form of bumps, dimples, or ramps. This simple and versatile model provides some new insights into a classical hydrodynamical problem.
Ultrafast vibrational dynamics of the tyrosine ring mode and its application to enkephalin insertion into phospholipid membranes as probed by two-dimensional infrared spectroscopy
Authors: Vinogradov Ilya , Feng Yuan , Kumar S. K. Karthick , Guo Chenxu , Udagawa Nina Saki , Ge Nien-Hui
Published: July 2021

Enkephalins are small opioid peptides whose binding conformations are catalyzed by phospholipid membranes. Binding to opioid receptors is determined by the orientation of tyrosine and phenylalanine side chains. In this work, we investigate the effects of different charged phospholipid headgroups on the insertion of the tyrosine side chain into a lipid bilayer using a combination of 2D IR spectroscopy, anharmonic DFT calculations, and third order response function modeling. The insertion is probed by using the ∼1515 cm−1 tyrosine ring breathing mode, which we found exhibits rich vibrational dynamics on the picosecond timescale. These dynamics include rapid intramolecular vibrational energy redistribution (IVR), where some of the energy ends up in a dark state that shows up as an anharmonically shifted combination band. The waiting-time dependent 2D IR spectra also show an unusual line shape distortion that affects the extraction of the frequency–frequency correlation function (FFCF), which is the dynamic observable of interest that reflects the tyrosine side chain’s insertion into the lipid bilayer. We proposed three models to account for this distortion: a hot-state exchange model, a local environment dependent IVR model, and a coherence transfer model. A qualitative analysis of these models suggests that the local environment dependent IVR rate best explains the line shape distortion, while the coherence transfer model best reproduced the effects on the FFCF. Even with these complex dynamics, we found that the tyrosine ring mode’s FFCF is qualitatively correlated with the degree of insertion expected from the different phospholipid headgroups.
Flow dynamics of shear-coaxial cryogenic nitrogen jets under supercritical conditions with and without acoustic excitations
Authors: Liu Tao , Wang Xingjian , Yang Vigor
Published: July 2021

The three-dimensional flow structures and dynamics of shear-coaxial nitrogen jets under supercritical conditions are comprehensively investigated using the large-eddy simulation technique. The theoretical framework is based on the full conservation laws and accommodates real-fluid thermodynamics and transport theories over the entire range of fluid states. Cryogenic liquid nitrogen (132 K) is delivered through the inner tube of a shear-coaxial nozzle, and gaseous nitrogen (191 K) is injected through the outer annulus, into a high-pressure environment at 233 K. Particular attention is paid to the influence of operating parameters on the flow evolution of the coaxial jets. Two supercritical pressure conditions, 4.94 and 10.0 MPa, and three outer-to-inner velocity ratios in the range of 2.03–3.75, are considered. Results reveal that the flowfield downstream of the coaxial jets is characterized by two potential cores and three shear layers. Two counter-rotating recirculation zones are formed next to the central post-tip. The characteristic frequencies of flow recirculation and shear-layer instability are analyzed using power spectral analysis. Increasing the pressure and the velocity ratio enhances turbulent mixing, promotes the entrainment of the outer stream into the inner region, and advances the pinching point of vortical motion to the centerline, thereby leading to a decreased length of the inner dark core. The predicted dark core length and outer spreading angle show good agreement with experimental results. The introduction of transverse acoustic excitation induces large sinusoidal oscillations of the inner dense-fluid stream along the direction of acoustic motion and promotes the mixing of the inner and outer streams.
Internal molecular conformation of organic glasses: A NEXAFS study
Authors: Zuhaib Amara , Urquhart Stephen G.
Published: July 2021

The origin of the exceptional stability of molecular glasses grown by physical vapor deposition (PVD) is not well understood. Differences in glass density have been correlated with thermodynamic stability for thin films of N,N′-Bis(3-methylphenyl)-N,N′-diphenylbenzidine (TPD) grown by PVD at specific substrate temperatures below the glass transition temperature. However, the relationship between the internal conformation of glass molecules and the thermodynamic properties of molecular glasses is not well studied. We use carbon 1s near edge x-ray absorption fine structure (NEXAFS) spectroscopy to examine different TPD sample preparations in which differences in the thermodynamic stability of the glass are known. Density functional theory simulations of the NEXAFS spectra of TPD allow us to attribute spectroscopic differences to changes in the internal conformation of the TPD molecule and relate this conformation to the stability of the TPD glass. This provides a direct experimental measurement of the internal conformation of molecules forming an organic glass.
Out-of-equilibrium optomechanical resonance self-excitation
Authors: Milde P. , Langenhorst M. , Hölscher H. , Rottmann-Matthes J. , Hundertmark D. , Eng L. M. , Hoffmann-Vogel R.
Published: July 2021

The fundamental sensitivity limit of atomic force microscopy is strongly correlated to the thermal noise of cantilever oscillation. A method to suppress this unwanted noise is to reduce the bandwidth of the measurement, but this approach is limited by the speed of the measurement and the width of the cantilever resonance, commonly defined through the quality factor Q. However, it has been shown that optomechanical resonances in interferometers might affect cantilever oscillations resulting in an effective quality factor Qeff. When the laser power is sufficiently increased cantilever oscillations might even reach the regime of self-oscillation. In this self-oscillation state, the noise of the system is partially determined by the interaction with laser light far from equilibrium. Here, we show and discuss how tuning of laser power leads to nonlinear optomechanical effects that can dramatically increase the effective quality factor of the cantilever leading to out-of-equilibrium noise. We model the effects using a fourth order nonlinearity of the damping coefficient.
Acoustic signatures and bubble entrainment mechanisms of a drop impacting a water surface with surfactant
Authors: Gillot G. , Simon L. , Génevaux J.-M. , Benyahia L.
Published: July 2021

The acoustics of a water drop impact on a bath of water and sodium dodecyl sulfate (SDS) is studied close to the irregular entrainment regime. In particular, acoustic events, corresponding to bubble vibration, are observed for several SDS concentrations. These acoustic events are induced by five different kinds of hydrodynamic events, including four different bubble entrainment mechanisms and one bubble excitation mechanism. These families of events appear to have their own acoustic signature. The different mechanisms are described in detail and typical signals belonging to these families are presented. Their main features are highlighted and linked to the hydrodynamics of the corresponding event.
Molecular dynamics simulations of void-mediated polarization vortex domain switching in compressed BaTiO3 nanofilm
Authors: Peng Di , Yang Xinhua , Jiang Wenkai , Tian Xiaobao
Published: July 2021

Molecular dynamics simulations based on the anisotropic shell model with the first-principles parameters are performed to investigate the void-mediated polarization vortex domain switching in compressed BaTiO3 nanofilms. When a unit-cell-size void is located at the nanofilm center, the polarization configuration is in a single-vortex state instead of a multi-vortex state. For different void length fractions along the [100] lattice orientation, a cylindrical vortex is formed around the void while a few small vortexes nucleate closely above and/or below the void. With increasing void area fraction in the [100] plane, the vortex around the void gradually switches from clockwise to counterclockwise. Both the void shape and orientation have important effects on the vortex domain switching. A void near the model center tends to induce a clockwise vortex around it, a void in the lower left region of model to motivate a counterclockwise vortex, but a void in other locations to induce a closure domain with different switching degrees. In addition, it is found that the degree of closure domain switching could be kept if a void changes its location only in a small area. These observations should be instructive for the design and application of ferroelectric devices.
Funneling dynamics in a phenylacetylene trimer: Coherent excitation of donor excitonic states and their superposition
Authors: Breuil Gabriel , Mangaud Etienne , Lasorne Benjamin , Atabek Osman , Desouter-Lecomte Michèle
Published: July 2021

Funneling dynamics in conjugated dendrimers has raised great interest in the context of artificial light-harvesting processes. Photoinduced relaxation has been explored by time-resolved spectroscopy and simulations, mainly by semiclassical approaches or referring to open quantum systems methods, within the Redfield approximation. Here, we take the benefit of an ab initio investigation of a phenylacetylene trimer, and in the spirit of a divide-and-conquer approach, we focus on the early dynamics of the hierarchy of interactions. We build a simplified but realistic model by retaining only bright electronic states and selecting the vibrational domain expected to play the dominant role for timescales shorter than 500 fs. We specifically analyze the role of the in-plane high-frequency skeletal vibrational modes involving the triple bonds. Open quantum system non-adiabatic dynamics involving conical intersections is conducted by separating the electronic subsystem from the high-frequency tuning and coupling vibrational baths. This partition is implemented within a robust non-perturbative and non-Markovian method, here the hierarchical equations of motion. We will more precisely analyze the coherent preparation of donor states or of their superposition by short laser pulses with different polarizations. In particular, we extend the π-pulse strategy for the creation of a superposition to a V-type system. We study the relaxation induced by the high-frequency vibrational collective modes and the transitory dissymmetry, which results from the creation of a superposition of electronic donor states.
Absolute calibration of the latent heat of transition using differential thermal analysis
Authors: Bar Tapas , Bansal Bhavtosh
Published: July 2021

We describe a simple and accurate differential thermal analysis setup to measure the latent heat of solid state materials undergoing abrupt phase transitions in the temperature range from 77 K to above room temperature. We report a numerical technique for the absolute calibration of the latent heat of transition without the need for a reference sample. The technique is applied to three different samples—vanadium sesquioxide undergoing the Mott transition, bismuth barium ruthenate undergoing a magnetoelastic transition, and an intermetallic Heusler compound. In each case, the inferred latent heat value agrees with the literature value within its error margins. To further demonstrate the importance of absolute calibration, we show that the changes in the latent heat of the Mott transition in vanadium sesquioxide (V2O3) remain constant to within 2% even as the depth of supersaturation changes by about 10 K in non-equilibrium dynamic hysteresis measurements. We also apply this technique for the measurement of the temperature-dependent specific heat.
Vortex flow evolution in a growing microdroplet during co-flow in coaxial capillaries
Authors: Vagner S. A. , Patlazhan S. A. , Serra C. A. , Funfschilling D.
Published: July 2021

Using micro-particle image velocimetry (μPIV), the convective flow inside a silicone oil droplet was investigated in detail during its formation in coaxial capillaries under co-flow in a water/glycerol mixture continuous phase. The analysis of μPIV measured flow field revealed that two characteristic flow areas exist in the droplet in formation: an inflow zone and a circulation zone. The intensity of vortex flow in these zones was estimated by calculating the average angular velocity of these vortices under the condition of no shear for different dispersed phase and continuous phase flow rates and for different viscosity ratios between the two phases. The evolution of the vortex flow pattern inside the droplet was investigated thoroughly all the way from the step of their formation to the step of the free-moving droplet. The results of this study are important for understanding the mixing processes inside the droplet at different stages of its formation.
Doping effect on the structure and properties of eight-electron silver nanoclusters
Authors: Zhong Yu-Jie , Liao Jian-Hong , Chiu Tzu-Hao , Gam Franck , Kahlal Samia , Saillard Jean-Yves , Liu C. W.
Published: July 2021

The bimetallic M20 and M21 compounds, {[Cu3Ag17{S2P(OiPr)2}12]0.5 [Cu4Ag16{S2P(OiPr)2}12]0.5} ({[1a]0.5[1b]0.5}) and [Cu4Ag17{S2P(OiPr)2}12](PF6) (2), have been structurally characterized, in which the Cu(I) ions are randomly distributed on the eight outer positions capping the eight-electron [Ag13]5+ core. DFT calculations show that the statistical disorder results from the nearly neutral preference of copper to occupy any of the eight outer positions. Surprisingly, the UV–Vis absorption spectra of the M20 and M21 bimetallic nanoclusters display an almost identical absorption profile as that of their homometallic [Ag20{S2P(OiPr)2}12] and [Ag21{S2P(OiPr)2}12]+ relatives. This is rationalized by TD-DFT calculations, which show that the frontier orbitals of such eight-electron alloys are largely independent from the nature of the capping metal ions. A blue-shifted absorption is observed upon replacing by Au the central Ag atom in 2, forming the trimetallic compound [Cu4AuAg16{S2P(OiPr)2}12](PF6) (3).
CD8 coreceptor-mediated focusing can reorder the agonist hierarchy of peptide ligands recognized via the T cell receptor
Authors: Clement Mathew , Knezevic Lea , Dockree Tamsin , McLaren James E. , Ladell Kristin , Miners Kelly L. , Llewellyn-Lacey Sian , Rubina Anzelika , Francis Ore , Cole David K. , Sewell Andrew K. , Bridgeman John S. , Price David A. , van den Berg Hugo A. , Wooldridge Linda
Published: July 2021

Significance

Sufficient immune coverage of the peptide universe within a finite host requires highly degenerate T cell receptors (TCRs). However, this inherent need for antigen cross-recognition is associated with a high risk of autoimmunity, which can only be mitigated by a process of adaptable specificity. We describe a mechanism that resolves this conundrum by allowing individual clonotypes to focus on specific peptide ligands without alterations to the structure of the TCR.
Vocal learning and flexible rhythm pattern perception are linked: Evidence from songbirds
Authors: Rouse Andrew A. , Patel Aniruddh D. , Kao Mimi H.
Published: July 2021

Significance

We can recognize the cadence of a friend’s voice or the rhythm of a familiar song across a wide range of tempi. This shows that our perception of temporal patterns relies strongly on the relative timing of events rather than on specific absolute durations. This tendency is foundational to speech and music perception, but to what extent is it shared by other species? We hypothesize that animals that learn their vocalizations are more likely to share this tendency. Here, we show that a vocal learning songbird robustly recognizes a basic rhythmic pattern independent of rate. Our findings pave the way for neurobiological studies to identify how the brain represents and perceives the temporal structure of auditory sequences.
Overriding native cell coordination enhances external programming of collective cell migration
Authors: Shim Gawoon , Devenport Danelle , Cohen Daniel J.
Published: July 2021

Significance

As collective cellular migration is critical for multicellular processes such as healing, approaches to reprogram it are of great interest. However, little is known about what happens when external “commands” clash with natural collective behaviors in a tissue. We investigate this question using a bioelectric stimulus—electrotaxis—to externally program cell migration in large, cultured layers of primary mouse skin monolayers, demonstrating how strong endogenous cell coordination competes with external migration commands, reducing tissue responsiveness to the commands and even causing significant cellular damage. However, we show that specifically weakening natural cell coordination by disrupting E-cadherin–mediated cell–cell adhesion improves our ability to control collective cell migration. These results offer a general approach to externally controlling highly coordinated tissues.
Structural basis for potassium transport in prokaryotes by KdpFABC
Authors: Sweet Marie E. , Larsen Casper , Zhang Xihui , Schlame Michael , Pedersen Bjørn P. , Stokes David L.
Published: July 2021

Significance

Potassium is the major intracellular cation in all kingdoms of life. In bacteria, potassium is used to maintain membrane potential, pH, and to provide turgor pressure for cell growth and division. When external potassium levels are low, an ATP-dependent pump called KdpFABC is essential to maintain intracellular potassium levels. This protein complex comprises a subunit descending from potassium channels and another from P-type ATPases. We used cryogenic electron microscopy to investigate this unique partnership and to address mechanisms of energy coupling and transport. We present structures corresponding to all major reaction intermediates and map distinct densities along the proposed transport pathway. Based on this data, we describe a mechanism that is unique amongst known membrane transporters.
The Type I interferon antiviral gene program is impaired by lockdown and preserved by caregiving
Authors: Cole Steven W. , Cacioppo John T. , Cacioppo Stephanie , Bone Kyle , Del Rosso Laura A. , Spinner Abigail , Arevalo Jesusa M. G. , Dizon Thomas P. , Capitanio John P.
Published: July 2021

Significance

“Shelter in place” (SIP) orders have been deployed to slow the spread of SARS-CoV-2, but they induce social isolation that may paradoxically weaken antiviral immunity. We examined the impact of 2-wk SIP on immune cell population dynamics and gene regulation in 21 adult rhesus macaques, finding 30 to 50% declines in circulating immune cells, decreases in antiviral gene expression, and increased inflammatory cells in blood and inflammatory gene expression in lymph nodes. Declines in antiviral gene expression (but not circulating immune cells) were blocked by the presence of a novel juvenile partner during SIP, suggesting a potential strategy for maintaining antiviral immunity during SIP by enhancing prosocial engagement.
Carotenoid biomarkers in Namibian shelf sediments: Anoxygenic photosynthesis during sulfide eruptions in the Benguela Upwelling System
Authors: Ma Jian , French Katherine L. , Cui Xingqian , Bryant Donald A. , Summons Roger E.
Published: July 2021

Significance

Anoxygenic photosynthesis by phototrophic sulfur bacteria is prevalent in microbial mat ecosystems and in restricted, highly stratified aquatic environments. This limited distribution reflects their simultaneous requirements for an anoxic habitat, reduced sulfur to supply electrons for carbon fixation, and an appropriate light regime. Although these conditions were often satisfied in ancient seas, as shown by the distinctive carotenoid and chlorophyll pigments preserved in geological samples going back as far as 1.65 billion y, we can find no record of these organisms growing in today’s generally well-ventilated oceans. An array of carotenoids in sediments from the Namibian shelf suggests that green sulfur bacteria, despite their sensitivity to oxygen, can proliferate during episodic toxic gas eruptions in the Benguela Upwelling System.
Understanding the translingual practices among international students in multilingual cities
Authors: Yin Yijun , Chik Alice , Falloon Garry
Published: July 2021

The impact of global mobility and technology innovations on urban linguistic diversity poses a key challenge to
understand how and to what extent international students are immersed in the target language. Such diversity of languages and
modes of communication has pointed to a fundamental transformation in the way that international students interact with both
online and offline resources. The translingual practices of Chinese international students presented in this study suggest that,
instead of being a language learner in an English-dominant country, these students make use of but go beyond their full
repertoires to conduct various online and offline activities when living in a translanguaging space. An evaluation of both online
and offline practices demonstrates how their online translingual practices were merged into offline contexts, to create
opportunities for learning and social engagement. Understanding international students’ experience with both online and offline
resources provides useful insights into the translingual practices and processes adopted by them when living and studying in a
multilingual city.
Migrants are not welcome
Authors: Benczes Réka , Ságvári Bence
Published: July 2021

Figurative framing, in the form of metaphorical expressions, is especially effective in carrying conceptual content on an
issue and affecting public opinion. One topic that has been heavily debated in contemporary Hungarian media is migration. Framing starts
with the label that journalists select to refer to fled people: bevándorló (“immigrant”), migráns
(“migrant”) or menekült (“refugee”). Depending on the label, different associations emerge, resting upon differing
(metaphorical) conceptualizations evoked by the labels. We analysed metaphorical compounds based on the keywords in a media corpus of
approx. 15 million words. Our results indicate that while all three keywords evoke predominantly negative frames and evaluations that build
on stock metaphorical conceptualizations of fled people as also identified in the international literature – such as flood, object,
business, war and crime –, the distribution of these metaphors does vary, depending on a) the selected keyword; and b) the
political agenda of the media source.
Poisoning the information well?
Authors: Tandoc Jr. Edson C. , Duffy Andrew , Jones-Jang S Mo , Wen Pin Winnie Goh
Published: July 2021

This study examines the impact of fake news discourse on perceptions of news media credibility. If participants
are told they have been exposed to fake news, does this lead them to trust information institutions less, including the news
media? Study 1 (n = 188) found that news media credibility decreased when participants were told they saw fake
news, while news credibility did not change when participants were told they saw real news. Study 2 (n = 400)
found that those who saw fake news – and were told they saw a fake news post – decreased their trust in the news media while those
who saw fake news and were not debriefed did not change their perceptions of the news media. This shows that the social impact of
fake news is not limited to its direct consequences of misinforming individuals, but also includes the potentially adverse effects
of discussing fake news.
A corpus-assisted analysis of the discursive construction of LGBT Singaporeans in media coverage of Pink Dot
Authors: Phillips Robert
Published: July 2021

Beginning in spring 2009 and continuing annually since, members of Singapore’s LGBT communities have assembled at Hong Lim
Park at an event dubbed Pink Dot. The original goal of the gathering was to help build a more inclusive nation by standing up to
discrimination faced by LGBT Singaporeans. While the early Pink Dot events were all but ignored by the mainstream state-run press, the
change in tone, the increasing number of attendees, and the participation by members of the ruling People’s Action Party and their families
made the gathering impossible to ignore. This paper uses a corpus-based keywords analysis to evaluate the main lexical differences between
the media coverage of Pink Dot by the state-run press and that of the sociopolitical blog The Online Citizen. Two separate
language corpora (State Media and Online Citizen), each containing approximately 111,000 words, were compiled from available coverage of
Pink Dot dating from 2009 to 2018. Using SketchEngine (Kilgarriff et al. 2004, 2014), top keywords and phrases were identified by comparing these corpora to each other. Through a
preliminary exploration of the collocational environments and the concordance lines adjoining these keywords, this paper sheds light on how
language is being deployed in an attempt to sway a debate of great national and regional significance.
A typology of Goal-Source marking in transfer events
Authors: Kittilä Seppo
Published: July 2021

This paper discusses the coding of Goals and Sources from a cross-linguistic perspective and proposes a formal-functional typology based on how animacy and direction affect their coding. The proposed typology comprises three types; Goal vs. Source-languages, animacy and direction-languages, and variable types. The paper shows that the coding of Goals and Sources is primarily conditioned by their semantic roles (by the direction of transfer/motion), but animacy makes an important contribution in some languages as well. Moreover, the paper will also show that animacy affects the coding of Goals more drastically than it affects the coding of Sources. Goals and Sources differ from each other also in that Goals are more often coded by cases, while Sources are usually more peripheral participants and they are thus often marked by adpositions. One of the proposed reasons for this is found in the goal-oriented nature of humans.
Angulin-1 seals tricellular contacts independently of tricellulin and claudins
Authors: Sugawara Taichi , Furuse Kyoko , Otani Tetsuhisa , Wakayama Tomohiko , Furuse Mikio
Published: July 2021

Tricellular tight junctions (tTJs) are specialized tight junctions (TJs) that seal the intercellular space at tricellular contacts (TCs), where the vertices of three epithelial cells meet. Tricellulin and angulin family membrane proteins are known constituents of tTJs, but the molecular mechanism of tTJ formation remains elusive. Here, we investigated the roles of angulin-1 and tricellulin in tTJ formation in MDCK II cells by genome editing. Angulin-1–deficient cells lost the plasma membrane contact at TCs with impaired epithelial barrier function. The C terminus of angulin-1 bound to the TJ scaffold protein ZO-1, and disruption of their interaction influenced the localization of claudins at TCs, but not the tricellular sealing. Strikingly, the plasma membrane contact at TCs was formed in tricellulin- or claudin-deficient cells. These findings demonstrate that angulin-1 is responsible for the plasma membrane seal at TCs independently of tricellulin and claudins.
A review of the structural diversity of [P
x
S
y
]
n

− motifs and their potential application prospects in metal thiophosphates
Authors: Yang Ya , Song Miao , Wu Xiaowen , Wu Kui
Published: July 2021

Metal thiophosphates have wide potential critical applications in various fields, such as nonlinear optical materials, magnetic materials, photoluminescence materials and solid electrolytes. However, a detailed review of the relationship among structure, performance and application in thiophosphates has not been reported so far. In this work, we have undertaken integrated generalization for the structural features and application prospects of 312 known metal thiophosphates (117 ternary and 195 quaternary). A survey of their crystal structures shows that they have various link modes used to form the [P
x
S
y
]
n

− ligands through the [PS4]3− building unit, for example, the ethane-like [P2S6]4− dimer, edge-sharing [P2S6]2−, corner-sharing [P2S7]4−, cyclic [P3S9]3− cluster, corner-sharing [P3S10]5− cluster, corner-sharing [P4S13]6− cluster and corner-sharing [P4S12]4− ring. Interestingly, various (P-S) ligands can also link other motifs to compose different structural features including zero-dimensional (0D) clusters, 1D chains, 2D layers and 3D networks. A detailed survey provides clear recognition of the inherent structure–performance relationship for thiophosphates and this result also illustrates that thiophosphates have huge potential as superior multifunctional materials.
Estimating the mechanical energy of histotripsy bubble clouds with high frame rate imaging
Authors: Bader Kenneth B , Wallach Emily L , Shekhar Himanshu , Flores-Guzman Fernando , Halpern Howard J , Hernandez Sonia L
Published: July 2021

Mechanical ablation with the focused ultrasound therapy histotripsy relies on the generation and action of bubble clouds. Despite its critical role for ablation, quantitative metrics of bubble activity to gauge treatment outcomes are still lacking. Here, plane wave imaging was used to track the dissolution of bubble clouds following initiation with the histotripsy pulse. Information about the rate of change in pixel intensity was coupled with an analytic diffusion model to estimate bubble size. Accuracy of the hybrid measurement/model was assessed by comparing the predicted and measured dissolution time of the bubble cloud. Good agreement was found between predictions and measurements of bubble cloud dissolution times in agarose phantoms and murine subcutaneous SCC VII tumors. The analytic diffusion model was extended to compute the maximum bubble size as well as energy imparted to the tissue due to bubble expansion. Regions within tumors predicted to have undergone strong bubble expansion were collocated with ablation. Further, the dissolution time was found to correlate with acoustic emissions generated by the bubble cloud during histotripsy insonation. Overall, these results indicate a combination of modeling and high frame rate imaging may provide means to quantify mechanical energy imparted to the tissue due to bubble expansion for histotripsy.
The impact of fuelling and W radiation on the performance of high-power, ITER-baseline scenario plasmas in JET-ILW
Authors: Field A R , Aleiferis S , Belonohy É , Carvalho P , Coffey I , Frigione D , Garzotti L , Horvath L , Kim Hyun-Tae , Lennholm M , Lerche E , Lomas P , Lowry C G , Mailloux J , Rimini F , Roach C M , Sertoli M , Štancar Ž , Szepesi G , van Eester D
Published: July 2021

Sustained operation of high-performance, ITER-baseline scenario plasmas at the high levels of input power (

≲

40

MW

) required to achieve ∼15 MW of D-T fusion power in JET-ILW requires careful optimisation of the fuelling to avoid an unacceptable disruption rate due to excessive radiation, primarily from W impurities, which are sputtered by edge-localised modes (ELMs) from the divertor targets. By using a train of ELM-pacing pellets from a high-frequency pellet injector to promote regular ELMs, which flush W and other impurities from the confined plasma, such high-performance plasmas can be sustained (for ∼5 s) while maintaining a high normalised confinement factor H
98,y2 ∼ 1, which would otherwise be degraded by reducing the pedestal confinement if a higher rate of D2 gas fuelling were used instead of the pellets to mitigate the W contamination. The causes underlying the improved performance and energy confinement obtained using this combined, gas and pellet fuelling scheme is investigated here in some detail.
Numerical and experimental analysis of radiation from a microwave plasma source of the TIAGO type
Authors: Nowakowska Helena , Czylkowski Dariusz , Hrycak Bartosz , Jasiński Mariusz
Published: July 2021

Unshielded microwave plasma sources radiate electromagnetic energy into space, which reduces the energy that can be used for plasma generation, contributes to discharge instability and is detrimental to laboratory personnel and equipment. We perform numerical analysis of radiation from a TIAGO torch, operating at 2.45 GHz, in which the plasma is generated at atmospheric pressure in the form of a flame at the tip of a metal nozzle. The analysis is carried out by solving the vector wave equation as for the antenna, with the assumption of axial symmetry and homogeneous electron density in the range of 1020–1022 m−3. We determine 2D electric field distributions inside a radiation sphere and radiation patterns for an unshielded torch and for a torch with shielding tubes with radii up to 100 mm and heights up to 200 mm. We also investigate the effect of the electron density, the tube height and radius on the reflected wave power, power absorbed in the plasma, radiated power and power entering the discharge. The results show that a tube of 25 mm radius (smaller than the cut-off radius) shields radiation very well, while the ratio of the radiated power to the entering power can achieve 85% for the unshielded torch and over 95% for a tube of 55 mm radius. In the experiment, we found that the powers required to ignite the discharge and to sustain it are about 80% greater and the plasma length is much shorter for a 55 mm radius tube than for a 25 mm radius tube, which we explain by the difference in the radiated power. The power density at a distance of 500 mm from the plasma with the entering power of 650 W depends on the direction and can exceed the permissible values several times. These results are consistent with calculations and indicate the need for appropriate shielding of the discharge.
In-situ measurements of the effect of radiation damage on the superconducting properties of coated conductors
Authors: Iliffe W , Peng N , Brittles G , Bateman R , Webb R , Grovenor C , Speller S
Published: July 2021

An apparatus has been built to perform irradiation and electrical testing of REBCO coated conductors (CC) held below their critical temperature (T
c). Patterned tracks of Fujikura GdBCO CC were irradiated with 2 MeV He+ ions in steps up to 4 mdpa whilst held at 40 K, and the critical current density (J
c) determined from I–V characteristics. These ‘in-situ’ samples then underwent annealing experiments at room temperature. The superconducting performance, both before and after room temperature annealing, has been compared to equivalent samples irradiated at room temperature and then cooled for testing at 40 K to understand how the damage tolerance of these materials is affected by sample temperature. Details of the apparatus and experimental results from preliminary work are presented and discussed. These preliminary results show that both T
c and J
c values of patterned tracks degrade with irradiation dose, with most samples showing similar behaviour. The room temperature annealing of ‘in-situ’ irradiated samples resulted in a significant recovery of properties. We conclude that irradiation temperature does alter how the superconducting properties of GdBCO CC are affected by ion irradiation, and that this observation has implications for the design of high temperature superconducting magnets for future fusion reactors.
Global-scale changes to extreme ocean wave events due to anthropogenic warming
Authors: Morim Joao , Vitousek Sean , Hemer Mark , Reguero Borja , Erikson Li , Casas-Prat Merce , Wang Xiaolan L , Semedo Alvaro , Mori Nobuhito , Shimura Tomoya , Mentaschi Lorenzo , Timmermans Ben
Published: July 2021

Extreme surface ocean waves are often primary drivers of coastal flooding and erosion over various time scales. Hence, understanding future changes in extreme wave events owing to global warming is of socio-economic and environmental significance. However, our current knowledge of potential changes in high-frequency (defined here as having return periods of less than 1 year) extreme wave events are largely unknown, despite being strongly linked to coastal hazards across time scales relevant to coastal management. Here, we present global climate-modeling evidence, based on the most comprehensive multi-method, multi-model wave ensemble, of projected changes in a core set of extreme wave indices describing high-frequency, extra-tropical storm-driven waves. We find changes in high-frequency extreme wave events of up to ∼50%–100% under RCP8.5 high-emission scenario; which is nearly double the expected changes for RCP4.5 scenario, when globally integrated. The projected changes exhibit strong inter-hemispheric asymmetry, with strong increases in extreme wave activity across the tropics and high latitudes of the Southern Hemisphere region, and a widespread decrease across most of the Northern Hemisphere. We find that the patterns of projected increase across these extreme wave events over the Southern Hemisphere region resemble their historical response to the positive anomaly of the Southern Annular Mode. Our findings highlight that many countries with low-adaptive capacity are likely to face increasing exposure to much more frequent extreme wave events in the future.