bluuebunny/crossref_metadata_2025 huggingface dataset:
Local electric field perturbations due to trapping mechanisms at defects: What random telegraph noise reveals
Authors: Vecchi Sara , Pavan Paolo , Puglisi Francesco Maria
Published: March 2023

As devices scale closer to the atomic size, a complete understanding of the physical mechanisms involving defects in high-κ dielectrics is essential to improve the performance of electron devices and to mitigate key reliability phenomena, such as Random Telegraph Noise (RTN). In fact, crucial aspects of defects in HfO2 are still under investigation (e.g., the presence of metastable states and their properties), but it is well known that oxygen vacancies (V+s) and oxygen ions (O0s) are the most abundant defects in HfO2. In this work, we use simulations to gain insights into the RTN that emerges when a constant voltage is applied across a TiN/(4 nm)HfO2/TiN stack. Signals exhibit different RTN properties over bias and, thus, appear to originate from different traps. Yet, we demonstrate that they can be instead promoted by the same O0s which change their capture (τc) and emission (τe) time constants with the applied bias, which, in turn, changes the extent of their electrostatic interactions with the traps that assist charge transport (V+s). For a certain bias, RTN is given by the modulation of the trap-assisted current at V+s induced by trapping/detrapping events at O0s, which are, in turn, influenced by the bias itself and by trapped charge at nearby O0s. In this work, we demonstrate that accounting for the effect of trapped charge is essential to provide accurate estimation of the RTN parameters, which allow us to retrieve information about traps and to explain key mechanisms behind complex RTN signals.
Reverse to forward density segregation depending on gas inflow velocity in vibrated fluidized beds
Authors: Jiang Zhaohua , Tsuji Takuya , Oshitani Jun , Washino Kimiaki , Tanaka Toshitsugu
Published: March 2023

Particle density segregations in vibrated fluidized beds depending on gas inflow velocity under the same vertical vibration condition are studied. Coarse-graining discrete element method and computational fluid dynamics numerical simulations are employed to capture the behaviors of reverse segregation in which heavy particles are located above light particles at zero gas inflow velocity or at velocities considerably lower than the minimum fluidization velocity of light particles. Furthermore, upon increasing the gas inflow velocity slightly, the forward segregation occurs, such that heavy particles are located below light particles. The mechanisms are also elucidated using the simulation results. Because of the relative motions between the particles and bed caused by vertical vibration, negative gauge pressure is observed to be dependent on the vibration phase. In the reverse segregation case, the accumulative effect of the downward gas pressure gradient force induced by vibration overcomes the upward force of the forced air flow. The wall friction transports both the heavy and light particles in the vicinity of the sidewall to the bed bottom, where the local void fraction is comparatively high and reverse segregation mainly occurs. Reverse segregation results from the combined effects of the downward gas pressure gradient force, particle transport, and local formation of the high void region. The increase in gas inflow velocity enhances the upward pressure gradient force, resulting in forward segregation.
Retraction and bouncing dynamics of nanodroplets upon impact on superhydrophobic surfaces
Authors: Wang Yi-Feng , Wang Yi-Bo , Zhang Cong-Lei , He Xin , Yang Yan-Ru , Zheng Shao-Fei , Lee Duu-Jong , Wang Xiao-Dong
Published: March 2023

This work investigates the retraction and bouncing dynamics of an impacting low-viscosity nanodroplet on superhydrophobic surfaces via molecular dynamics simulations, aiming to reveal the scaling laws of retraction and bouncing velocities and to establish the relationship between them. The retraction velocity, Vre, is found to scale as Vre ∼ Dmax/τc,n, where Dmax is the maximum spreading diameter, τc,n = (D0/V0)We1/2Oh1/3 is the inertial-capillary-viscous time, and We and Oh are the Weber number and Ohnesorge number, respectively. The bouncing stems from the collision of the retracting rim at the center of the nanodroplet, leading to the bouncing velocity scaling as the retraction velocity. Combining the relationship of Vre ∼ Dmax/τc,n with the scaling law of Dmax ∼ We1/2Oh1/3D0 yields both the retraction and bouncing velocities scaling as the impact velocity, indicating that both the retraction and bouncing velocities of low-viscosity nanodroplets on a superhydrophobic surface depend merely on the impact velocity. An energy analysis shows that the proportion of the surface energy at the maximum spreading state (Es,max) to the initial kinetic energy (Ek,ini) follows Es,max/Ek,ini ∼ Oh2/3, whereas the proportion of the bouncing kinetic energy (Ek,b) to the surface energy at the maximum spreading state follows Ek,b/Es,max ∼ Oh−2/3, leading to constant Ek,b/Ek,ini and also constant restitution coefficient for low-viscosity nanodroplets impacting superhydrophobic surfaces.
Magneto-responsive optics in a chiral crystal with thermally triggered reversible phase transitions between chiral space groups
Authors: Yang Yuying , Lu Xiangqian , Dong Xianfeng , Qin Wei
Published: March 2023

Herein, a chiral charge transfer crystal that exhibits reversible phase transition between chiral space groups has been fabricated. When the phase switches from left-handed to right-handed chiral space group, more pronounced orbital angular momentum effects will be generated, where magneto-responsive optics are the opposite for chiral enantiomers. Moreover, circularly polarized light could enhance the chiral orbit of the crystal with the same spiral orientation to let spin have a better ability to resist external magnetic field. Thus, the magnetic field dependence of transmission and photoluminescence of chiral crystals are strongly dependent on the polarized state of incident light. Furthermore, by studying the coupling among spin, orbit, and circular photon, we obtained that the chiral orbit plays a key role in the coupling between the spin and circular photon. It is expected that this work could promote further exploration of organic chiral magneto-optical crystals in potential applications of sensing.
Co-evolution of synchronization and cooperation with multi-agent Q-learning
Authors: Zhu Peican , Cao Zhaoheng , Liu Chen , Chu Chen , Wang Zhen
Published: March 2023

Cooperation is a widespread phenomenon in human society and plays a significant role in achieving synchronization of various systems. However, there has been limited progress in studying the co-evolution of synchronization and cooperation. In this manuscript, we investigate how reinforcement learning affects the evolution of synchronization and cooperation. Namely, the payoff of an agent depends not only on the cooperation dynamic but also on the synchronization dynamic. Agents have the option to either cooperate or defect. While cooperation promotes synchronization among agents, defection does not. We report that the dynamic feature, which indicates the action switching frequency of the agent during interactions, promotes synchronization. We also find that cooperation and synchronization are mutually reinforcing. Furthermore, we thoroughly analyze the potential reasons for synchronization promotion due to the dynamic feature from both macro- and microperspectives. Additionally, we conduct experiments to illustrate the differences in the synchronization-promoting effects of cooperation and dynamic features.
Surface viscosity in simple liquids
Authors: Malgaretti Paolo , Bafile Ubaldo , Vallauri Renzo , Jedlovszky Pál , Sega Marcello
Published: March 2023

The response of Newtonian liquids to small perturbations is usually considered to be fully described by homogeneous transport coefficients like shear and dilatational viscosity. However, the presence of strong density gradients at the liquid/vapor boundary of fluids hints at the possible existence of an inhomogeneous viscosity. Here, we show that a surface viscosity emerges from the collective dynamics of interfacial layers in molecular simulations of simple liquids. We estimate the surface viscosity to be 8–16 times smaller than that of the bulk fluid at the thermodynamic point considered. This result can have important implications for reactions at liquid surfaces in atmospheric chemistry and catalysis.
A novel ultrasonic non-destructive testing methodology to monitor fatigue crack growth in compact tension specimens
Authors: Abraham Saju T. , Babu M. Nani , Venkatraman B.
Published: March 2023

Detection and evaluation of fatigue cracks in structural materials are extremely important for life prediction analysis as part of the structural integrity procedure. In this article, we present a novel ultrasonic measurement methodology, based on the diffraction of elastic waves at the crack tips, to monitor the fatigue crack growth near the threshold regime in compact tension specimens at different load ratios. The diffraction phenomenon of ultrasonic waves from the crack tip is demonstrated using a finite element 2D wave propagation simulation. The applicability of this methodology has also been contrasted with that of the conventional direct current potential drop method. In addition, the crack morphology obtained in the ultrasonic c-scan imaging showed a variation in the crack propagation plane as a function of the cyclic loading parameters. The results suggest that this novel methodology is sensitive to fatigue cracks and can form the basis of in situ ultrasonic-based crack measurements in metallic and non-metallic materials.
Self-ejection of salts and other foulants from superhydrophobic surfaces to enable sustainable anti-fouling
Authors: McBride Samantha A. , Lake John R. , Varanasi Kripa K.
Published: March 2023

A recently discovered phenomenon in which crystalline structures grown from evaporating drops of saline water self-eject from superhydrophobic materials has introduced new possibilities for the design of anti-fouling materials and sustainable processes. Some of these possibilities include evaporative heat exchange systems using drops of saline water and new strategies for handling/processing waste brines. However, the practical limits of this effect using realistic, non-ideal source waters have yet to be explored. Here, we explore how the presence of various model aquatic contaminants (colloids, surfactants, and calcium salt) influences the self-ejection phenomena. Counterintuitively, we find that the addition of “contaminant” chemistries can enable ejection under conditions where ejection was not observed for waters containing only sodium chloride salt (e.g., from smooth hydrophobic surfaces), and that increased concentrations of both surfactants and colloids lead to longer ejection lengths. This result can be attributed to decreased crystallization nucleation time caused by the presence of other species in water.
Combined internal and external natural convection of Bingham plastics in a cavity using a lattice Boltzmann method
Authors: Kefayati Gholamreza
Published: March 2023

Natural convection of Bingham plastics in a cavity with differentially heated walls and an internal heat source is investigated numerically. The governing dimensional and non-dimensional macroscopic equations are presented, and the constitutive equation is written based on an exact Bingham model. The implemented lattice Boltzmann method is explained and showed how to derive the presented governing equations. The code is validated and verified against previous studies and exhibited a good agreement. The results are demonstrated and discussed for various non-dimensional parameters of Rayleigh (R = 102–104), Rayleigh–Roberts (RR = 102–106), Prandtl (Pr = 0.1–100), Bingham (Bn), and Yield (Y) numbers. The effects of the parameters are depicted on isotherms, yielded/unyielded zones, streamlines, and the lines of temperatures and velocities in the middle of the cavity. The maximum (or critical) Yield number (Ym) is found in the studied parameters and reported. The Yield number is independent of the Rayleigh and Prandtl numbers in a fixed ratio of R and RR (Δ = RR/R), like the external and internal convection. However, the alteration of Δ changes the unique value of the Yield number. We considered the three ratios of Δ = 1, 10, and 100 and the single maximum Yield number of the ratios for zero inclined angles (θ=0°) were observed at Ym=0.038,0.073, and 0.38, respectively. The increase in the inclined angle counter-clockwise expands the unyielded zones and declines the maximum Yield number.
NAl4X4+ (X = S, Se, Te): Clusters with a planar tetracoordinate nitrogen and significantly improved stability
Authors: Sun Rui , Yuan Caixia , Zhai Hua-Jin , Wu Yan-Bo
Published: March 2023

The design of clusters featuring non-classical planar hypercoordinate atoms (phAs) often depends on the delocalized multicenter bonds involving reactive electron-deficient elements, which both destabilize the clusters and lead to difficulty in achieving the phA arrangement for electronegative elements such as nitrogen due to their preference for localized bonds. In this work, we computationally designed a series of aluminum chalcogenide clusters NAl4X4+ (X = S, Se, Te) with a desired planar tetracoordinate nitrogen and meaningfully improved chemical stability, as evidenced by the wide gaps (6.51–7.23 eV) between their highest occupied molecular orbitals and lowest unoccupied molecular orbitals, high molecular rigidity (dynamically stable up to 1500 K), and exclusively low global energy minima nature (their isomers locate at least 51.2 kcal/mol higher). Remarkably, these clusters are stabilized by peripheral chalcogen atoms, which not only sterically protect the NAl4 core moiety but also electronically compensate for the electron-deficient aluminum atoms via X → Al π back bonds, meeting the description of our recently proposed “electron-compensation” strategy.
Mach cutoff phenomenon of sonic boom in temperature inversion layers
Authors: Yamashita Rei , Makino Yoshikazu
Published: March 2023

The Mach cutoff of sonic boom occurs when shock waves propagate from supersonic to subsonic regions in a stratified atmosphere. In this study, numerical simulations are performed to clarify Mach cutoff behaviors in atmospheric temperature inversion layers, which have not yet been investigated. The two-dimensional Euler equations with a gravitational source term are solved in a horizontally stratified atmosphere. Surface and non-surface temperature inversion layers include three and four supersonic–subsonic mixing layers, respectively. Computations are made to analyze the propagation characteristics of a conventional N-shaped waveform. The results show that multiple upward and downward cutoffs occur owing to atmospheric temperature inversions, with multiple outgoing and evanescent waves, and multiple shock wave focusing. The upward and downward cutoffs act similarly. The positive- and negative-pressure regions are inversed when a cutoff occurs twice; thus, each cutoff shifts a phase by π/2, as expressed in the linear theory of caustics. A waveform transition occurs owing to wave splitting in a cutoff region, in addition to the phase shift. For surface temperature inversion, upward cutoffs make the waves between the cutoff and ground surfaces persist, resulting in rumbling. For non-surface temperature inversion, upward and downward cutoffs occur alternately, and the waves between them persist as well. Therefore, multiple cutoffs in temperature inversion layers play an important role in sonic boom evaluation during low supersonic flight.
Linearly polarized emission from CdSe/CdS core-in-rod nanostructures: Effects of core position
Authors: Jang Hyejeong , Jung Dongju , Bae Wan Ki , Park Young-Shin , Lee Doh C.
Published: March 2023

Semiconductor nanocrystals with an anisotropic morphology exhibit unique properties, most notably their linear polarization. The colloidal growth of semiconductor nanorods with core dots inside, also referred to as dot-in-rod (DIR) structure, has enabled the synthesis of anisotropic nanocrystals with better stability and controllable fluorescence polarization. In this study, we synthesize CdSe/CdS DIR nanocrystals, in which the position of the CdSe core particle can be controlled by using different ligand compositions during the CdS growth. Varying the core position within the DIR structure, e.g., from the center to the end of the DIR particles, results in a change in the degree of linear polarization. When the core is positioned at the center of the nanorod, the linear polarization turns out to be higher compared with tip-core DIRs. Time-resolved photoluminescence analysis reveals that the center-core DIRs have higher electron–hole interaction than tip-core DIRs because of weak uniaxial strain in center-core DIR that arises from lattice dislocations at the interface to relieve accumulated strain.
Prehistoric Australasia
Authors: Archer Michael , Hand Suzanne , Long John , Worthy Trevor , Schouten Peter
Published: March 2023

For most of the past 300 million years, the world’s continents were interlinked as the supercontinents Pangaea and then Gondwana. Around 50 million years ago, Australia tore itself free from Antarctica to become the huge, splendidly isolated island it is today. Over time, its creatures began to evolve in ways not seen anywhere else on Earth, with tree-climbing crocodiles, gigantic venomous lizards, walking omnivorous bats and flesh-eating kangaroos roaming the continent.

Prehistoric Australasia: Visions of Evolution and Extinction presents some of the most extraordinary creatures the world has ever seen – all unique to Australia, New Guinea, New Zealand and their surrounding islands.

Over 100 meticulously painted panoramas by palaeoartist Peter Schouten are accompanied by descriptions of the unique environments and features of these animals, written by four of Australia’s foremost palaeontologists. This book explores the nature and timing of extinction events in the Southern Hemisphere, considers whether some of these losses might be able to be reversed, and how we can use the fossil record to help save today’s critically endangered species. Through stunning artwork and fascinating text, Prehistoric Australasia brings this globally unique transformation over time to glorious, colourful life.
Forgotten Song
Authors: Vass Coral , Racklyeft Jess
Published: March 2023

The song of the regent honeyeater has been heard in the bush for many generations – but could it soon be lost forever?

Regent’s father had learnt the song from his father, who learnt it from his father too. But with Regent’s species now facing extinction, there is no one around to teach him. Regent tries to mimic the sounds of different birds but without success.

Will Regent learn his mating call before it’s too late? Or will his ancient song be forgotten forever?

Reading level varies from child to child, but we recommend this book for ages 5 to 9.
Would men who have sex with men support less frequent screening for asymptomatic chlamydia and gonorrhoea to improve antibiotic stewardship? A qualitative study
Authors: Wardley Amelia Margaret , Williams Henrietta , Coombe Jacqueline , Caddy Cassandra , Fairley Christopher Kincaid , Hocking Jane Simone
Published: March 2023

Background Men who have sex with men (MSM) taking pre-exposure prophylaxis (PrEP) are recommended to have screening for asymptomatic chlamydia and gonorrhoea every 3 months with high rates of asymptomatic chlamydia and gonorrhoea detected. However, there is little evidence about the effectiveness of this screening interval and there is increasing concern about antibiotic consumption and its impact on antimicrobial resistance. There have been calls to reconsider this frequent screening for chlamydia and gonorrhoea. We conducted interviews with MSM to assess their attitudes to 3-monthly chlamydia and gonorrhoea screening. Methods Individual semi-structured interviews were conducted with MSM living in Victoria, Australia. Participants were aged 20–62 years and had been taking PrEP for at least 6 months. Interviews were audio-recorded and transcribed, and these data were investigated through reflexive thematic analysis. Results Thirteen interviews were conducted in August 2021. Participants were hesitant about reducing the screening frequency and reported that testing gave them a sense of security. While MSM recognised antimicrobial resistance was a concern, it did not impact their sexual behaviour, with many participants stating they would rather continue to take antibiotics to treat infections rather than adopt preventative measures such as condom use. Positive attitudes towards screening interval changes are more likely when PrEP patients are informed about the risks and benefits of sexual healthcare recommendations. Conclusion While MSM on PrEP were initially hesitant to changes in screening frequency, changes may be acceptable if transparent communication, presenting the benefits and harms of screening and treatment, was delivered by a trusted healthcare professional.
OPA1
disease-causing mutants have domain-specific effects on mitochondrial ultrastructure and fusion
Authors: Cartes-Saavedra Benjamín , Lagos Daniel , Macuada Josefa , Arancibia Duxan , Burté Florence , Sjöberg-Herrera Marcela K. , Andrés María Estela , Horvath Rita , Yu-Wai-Man Patrick , Hajnóczky György , Eisner Verónica
Published: March 2023

Inner mitochondrial membrane fusion and cristae shape depend on optic atrophy protein 1, OPA1. Mutations in
OPA1
lead to autosomal dominant optic atrophy (ADOA), an important cause of inherited blindness. The Guanosin Triphosphatase (GTPase) and GTPase effector domains (GEDs) of OPA1 are essential for mitochondrial fusion; yet, their specific roles remain elusive. Intriguingly, patients carrying
OPA1
GTPase mutations have a higher risk of developing more severe multisystemic symptoms in addition to optic atrophy, suggesting pathogenic contributions for the GTPase and GED domains, respectively. We studied
OPA1
GTPase and GED mutations to understand their domain-specific contribution to protein function by analyzing patient-derived cells and gain-of-function paradigms. Mitochondria from
OPA1
GTPase (c.870+5G>A and c.889C>T) and GED (c.2713C>T and c.2818+5G>A) mutants display distinct aberrant cristae ultrastructure. While all OPA1 mutants inhibited mitochondrial fusion, some GTPase mutants resulted in elongated mitochondria, suggesting fission inhibition. We show that the GED is dispensable for fusion and OPA1 oligomer formation but necessary for GTPase activity. Finally, splicing defect mutants displayed a posttranslational haploinsufficiency-like phenotype but retained domain-specific dysfunctions. Thus, OPA1 domain-specific mutants result in distinct impairments in mitochondrial dynamics, providing insight into OPA1 function and its contribution to ADOA pathogenesis and severity.
Strong connectivity in real directed networks
Authors: Rodgers Niall , Tiňo Peter , Johnson Samuel
Published: March 2023

In many real, directed networks, the strongly connected component of nodes which are mutually reachable is very small. This does not fit with current theory, based on random graphs, according to which strong connectivity depends on mean degree and degree–degree correlations. And it has important implications for other properties of real networks and the dynamical behavior of many complex systems. We find that strong connectivity depends crucially on the extent to which the network has an overall direction or hierarchical ordering—a property measured by trophic coherence. Using percolation theory, we find the critical point separating weakly and strongly connected regimes and confirm our results on many real-world networks, including ecological, neural, trade, and social networks. We show that the connectivity structure can be disrupted with minimal effort by a targeted attack on edges which run counter to the overall direction. This means that many dynamical processes on networks can depend significantly on a small fraction of edges.
Network inference from short, noisy, low time-resolution, partial measurements: Application to
C. elegans
neuronal calcium dynamics
Authors: Banerjee Amitava , Chandra Sarthak , Ott Edward
Published: March 2023

Network link inference from measured time series data of the behavior of dynamically interacting network nodes is an important problem with wide-ranging applications, e.g., estimating synaptic connectivity among neurons from measurements of their calcium fluorescence. Network inference methods typically begin by using the measured time series to assign to any given ordered pair of nodes a numerical score reflecting the likelihood of a directed link between those two nodes. In typical cases, the measured time series data may be subject to limitations, including limited duration, low sampling rate, observational noise, and partial nodal state measurement. However, it is unknown how the performance of link inference techniques on such datasets depends on these experimental limitations of data acquisition. Here, we utilize both synthetic data generated from coupled chaotic systems as well as experimental data obtained from
Caenorhabditis elegans
neural activity to systematically assess the influence of data limitations on the character of scores reflecting the likelihood of a directed link between a given node pair. We do this for three network inference techniques: Granger causality, transfer entropy, and, a machine learning-based method. Furthermore, we assess the ability of appropriate surrogate data to determine statistical confidence levels associated with the results of link-inference techniques.
Reproductive variance can drive behavioral dynamics
Authors: Wang Guocheng , Su Qi , Wang Long , Plotkin Joshua B.
Published: March 2023

The concept of fitness is central to evolution, but it quantifies only the expected number of offspring an individual will produce. The actual number of offspring is also subject to demographic stochasticity—that is, randomness associated with birth and death processes. In nature, individuals who are more fecund tend to have greater variance in their offspring number. Here, we develop a model for the evolution of two types competing in a population of nonconstant size. The fitness of each type is determined by pairwise interactions in a prisoner’s dilemma game, and the variance in offspring number depends upon its mean. Although defectors are preferred by natural selection in classical population models, since they always have greater fitness than cooperators, we show that sufficiently large offspring variance can reverse the direction of evolution and favor cooperation. Large offspring variance produces qualitatively new dynamics for other types of social interactions, as well, which cannot arise in populations with a fixed size or with a Poisson offspring distribution.
Transcription factor bHLH121 regulates root cortical aerenchyma formation in maize
Authors: Schneider Hannah M. , Lor Vai S. , Zhang Xia , Saengwilai Patompong , Hanlon Meredith T. , Klein Stephanie P. , Davis Jayne L. , Borkar Aditi N. , Depew Cody L. , Bennett Malcolm J. , Kaeppler Shawn M. , Brown Kathleen M. , Bhosale Rahul , Lynch Jonathan P.
Published: March 2023

Root anatomical phenotypes present a promising yet underexploited avenue to deliver major improvements in yield and climate resilience of crops by improving water and nutrient uptake. For instance, the formation of root cortical aerenchyma (RCA) significantly increases soil exploration and resource capture by reducing the metabolic costs of root tissue. A key bottleneck in studying such phenotypes has been the lack of robust high-throughput anatomical phenotyping platforms. We exploited a phenotyping approach based on laser ablation tomography, termedAnatomics, to quantify variation in RCA formation of 436 diverse maize lines in the field. Results revealed a significant and heritable variation for RCA formation. Genome-wide association studies identified a single-nucleotide polymorphism mapping to a root cortex-expressed gene-encoding transcription factor bHLH121. Functional studies identified that thebHLH121Mu transposon mutant line and CRISPR/Cas9 loss-of-function mutant line showed reduced RCA formation, whereas an overexpression line exhibited significantly greater RCA formation when compared to the wild-type line. Characterization of these lines under suboptimal water and nitrogen availability in multiple soil environments revealed thatbHLH121is required for RCA formation developmentally as well as under studied abiotic stress. Overall functional validation of thebHLH121gene’s importance in RCA formation provides a functional marker to select varieties with improved soil exploration and thus yield under suboptimal conditions.
EMBER multidimensional spectral microscopy enables quantitative determination of disease- and cell-specific amyloid strains
Authors: Yang Hyunjun , Yuan Peng , Wu Yibing , Shi Marie , Caro Christoffer D. , Tengeiji Atsushi , Yamanoi Shigeo , Inoue Masahiro , DeGrado William F. , Condello Carlo
Published: March 2023

In neurodegenerative diseases, proteins fold into amyloid structures with distinct conformations (strains) that are characteristic of different diseases. However, there is a need to rapidly identify amyloid conformations in situ. Here, we use machine learning on the full information available in fluorescent excitation/emission spectra of amyloid-binding dyes to identify six distinct different conformational strains in vitro, as well as amyloid-β (Aβ) deposits in different transgenic mouse models. Our EMBER (excitation multiplexed bright emission recording) imaging method rapidly identifies conformational differences in Aβ and tau deposits from Down syndrome, sporadic and familial Alzheimer’s disease human brain slices. EMBER has in situ identified distinct conformational strains of tau inclusions in astrocytes, oligodendrocytes, and neurons from Pick’s disease. In future studies, EMBER should enable high-throughput measurements of the fidelity of strain transmission in cellular and animal neurodegenerative diseases models, time course of amyloid strain propagation, and identification of pathogenic versus benign strains.
Focusing on the task and emotional self-regulation: daily challenges in the classroom (Lafocalización en el tema yautorregulación emocional: desafíos cotidianos en el aula escolar)
Authors: Alarcón-Espinoza Marina , Samper Paula , Anguera M. Teresa
Published: March 2023

Focusing on school tasks and regulating emotions are often challenges for students to achieve. The objective of this research is to describe and analyse the behaviours associated with emotional regulation that affect the way students participate in the classroom and contribute to the subject matter. From the mixed methods perspective, an observational study was carried out based on an N/F/M (Nomothetic/Follow-up/Multidimensional) design. The members of nine primary education classes were systematically observed. The data record, obtained from an instrument designed ad hoc, is qualitative, and is organized to be coded and analysed quantitatively. Once the classes were analysed, the presence of multiple cases was detected. The results show how the associated behaviours contribute, change, insist on and distract from the topic of conversation, influencing the way in which focused attention is maintained. The discussion highlights the existence of a ‘virtuous circle’ that favours focusing on the topic through the coexistence of the behaviours of contributing to the topic with an informative language and encouraging the participation of others.
Microstructure and tensile strength of electrodeposited Fe-rich bcc FeCoNi medium-entropy alloys
Authors: Watanabe A. , Yamamoto T. , Miyamoto R. , Takigawa Y.
Published: March 2023

Crystal grain refinement in high- and medium-entropy alloys is an effective approach to obtaining good strength as well as ductility. An FeCoNi medium-entropy alloy with a wide range of grain sizes was fabricated by electrodeposition. The alloy had a metastable bcc structure with Fe–36 at.% Co–21 at.% Ni composition and heterogeneous distribution of grain sizes ranging from 20 nm to 15 µm. Moreover, the alloy possessed a tensile strength of 1.2 GPa, and a fracture elongation of 6.3 % without secondary phase. The excellent mechanical properties of the alloy can be attributed to its bcc phase and heterogeneous grain sizes extending to the nanoscale.

GRAPHICAL ABSTRACT
Odd-parity perturbations in the most general scalar–vector–tensor theory
Authors: Rodríguez Baez Yolbeiker , Gonzalez-Espinoza Manuel
Published: March 2023

In the context of the most general scalar–vector–tensor theory, we study the stability of static spherically symmetric black holes under linear odd-parity perturbations. We calculate the action to second order in the linear perturbations to derive a master equation for these perturbations. For this general class of models, we obtain the conditions of no-ghost and Laplacian instability. Then, we study in detail the generalized Regge–Wheeler potential of particular cases to find their stability conditions.
Interpreting the cosmic history of the Universe through five-dimensional supergravity
Authors: Emam Moataz H , Salem Safinaz
Published: March 2023

Through modeling the Universe as a symplectic 3-brane embedded in the bulk of

five-dimensional ungauged supergravity theory, the entire evolution of the Universe can be interpreted from inflation to late-time acceleration without introducing an inflaton nor a cosmological constant. The time dependence of the brane is strongly correlated to the complex structure moduli of the underlying Calabi–Yau submanifold and the bulk effects. The solutions to the field equations are found by exploiting the theory’s symplectic structure where the time evolution is similar to our Universe according to the latest data of the Planck mission. Our results present a new explanation for the nature of dark energy mainly based on the topology of the subspace and the existence of a fifth extra dimension.
High-order matrix method with delimited expansion domain
Authors: Lin Kai , Qian Wei-Liang
Published: March 2023

Motivated by the substantial instability of the fundamental and high-overtone quasinormal modes (QNMs), recent developments regarding the notion of black hole pseudospectrum call for numerical results with unprecedented precision. This work generalizes and improves the matrix method for black hole QNMs to higher orders, specifically aiming at a class of perturbations to the metric featured by discontinuity intimately associated with the QNM structural instability. The approach is based on the mock-Chebyshev grid, which guarantees its convergence in the degree of the interpolant. In practice, solving for black hole QNMs is a formidable task. The presence of discontinuity poses a further difficulty so that many well-known approaches cannot be employed straightforwardly. Compared with other viable methods, the modified matrix method is competent in speed and accuracy. Therefore, the method serves as a helpful gadget for relevant studies.
Filtering linear polarization converters based on multi-mode unit for harmonic suppression
Authors: Qiu Leilei , Fang Shuguang , Zhu Lei , Huang Shengxiang , Wu Yueyang , Deng Lianwen
Published: March 2023

In this article, a class of filtering linear polarization converters based on a single quasi-single-layer triangular resonator unit is proposed. By loading the stub-line and slot lines, the degenerate modes of the single fundamental resonant mode of an isosceles right-angle patch are separated into two for a second-order filtering characteristic, and two additional resonant modes are then generated for the second conversion band. Attributed to the mixed electric and magnetic coupling in the coupling section of the loaded stub-line, several conversion zeros are introduced at the same time. As the contribution of this work, multiple resonant modes and conversion zeros can be independently controlled by the corresponding parameters, enabling second-order single- and dual-band response with multi-mode high selectivity side-band and harmonic rejection characteristics out-of-band. With the detailed analysis of the surface current and field distributions, the polarization conversion mechanisms are revealed. Finally, the single-band and dual-band linear polarization converters are processed, and the measured and simulated results are in good agreement. As expected, the two polarization converters show excellent filtering features, which is beneficial for improving modulation accuracy and avoiding unwanted electromagnetic interference in various applications of multi-passband and multi-functional metasurfaces.
A survey of patient contact shielding in dental teaching hospitals in the UK
Authors: Haworth S , Drage N
Published: March 2023

A high volume of dental imaging is carried out each year. In the UK, guidance on the use of patient contact shielding for these investigations is published by the British Institute of Radiology (BIR) and in a document jointly produced by the Faculty of General Dental Practice and Public Health England (FGDP/PHE). Both these sources of guidance have been updated recently and patient contact shielding is no longer recommended for most imaging settings in dental radiology. It is unclear whether radiology departments at dental teaching hospitals in the UK are aware of these sources of guidance, and how this relates to clinical practice within these departments. A survey was carried out exploring the awareness of current guidelines and clinical practice at dental teaching hospitals in the UK. The survey was sent to a representative at 17 different dental teaching hospital radiology departments. Responses were received from 11 departments. The range of intra-oral and extra-oral imaging carried out at these departments was comparable. Ten departments were aware of the existence of national guidelines for patient contact shielding, however only four were specifically aware of the recent BIR guidelines and only four were specifically aware of the FGDP/PHE guidelines. No department was aware of both sets of guidelines. No departments used thyroid protection for bitewing, periapical, lower 45 degree occlusal, panoramic or lateral cephalometric radiographs. Six departments sometimes or always used thyroid protection for upper standard occlusal imaging. Two departments used thyroid protection for cone beam CT imaging. No departments routinely used lead aprons on patients for dental imaging. In conclusion, radiology departments at dental teaching hospitals in the UK do not use patient contact shielding for most imaging situations in dental radiology. There is mixed awareness of current national guidelines, but the reported clinical practice aligns well with the current guidelines.
Deep reactive ion etching of cylindrical nanopores in silicon for photonic crystals
Authors: Goodwin Melissa J , Harteveld Cornelis A M , de Boer Meint J , Vos Willem L
Published: March 2023

Periodic arrays of deep nanopores etched in silicon by deep reactive ion etching are desirable structures for photonic crystals and other nanostructures for silicon nanophotonics. Previous studies focused on realizing as deep as possible nanopores with as high as possible aspect ratios. The resulting nanopores suffered from structural imperfections of the nanopores, such as mask undercut, uneven and large scallops, depth dependent pore radii and tapering. Therefore, our present focus is to realize nanopores that have as cylindrical as possible shapes, in order to obtain a better comparison of nanophotonic observations with theory and simulations. To this end in our 2-step Bosch process we have improved the mask undercut, the uneven scallops, pore widening and positive tapering by optimizing a plethora of parameters such as the etch step time, capacitively coupled plasma (ion energy) and pressure. To add further degrees of control, we implemented a 3-step DREM (deposit, remove, etch, multistep) process. Optimization of the etching process results in cylindrical nanopores with a diameter in the range between 280 and 500 nm and a depth around 7 μm, corresponding to high depth-to-diameter aspect ratios between 14 and 25, that are very well suited for the realization of silicon nanophotonic structures.
Preparation of ZIF-8/PAN composite nanofiber membrane and its application in acetone gas monitoring
Authors: Niu Ben , Zhai Zhenyu , Wang Jiaona , Li Congju
Published: March 2023

Znic-based metal–organic framework materials (ZIF-8) show great potential and excellent performance in the fields of sensing and catalysis. However, powdered metal–organic framework makes it easy to lose in the process of application. Herein, we use a simple blending electrostatic spinning method to combine ZIF-8 particles with polyacrylonitrile (PAN) nanofibers. ZIF-8/PAN composite nanofiber membrane. The ZIF-8/PAN nanofiber membrane is characterized by scanning electron microscope (SEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and N2 adsorption–desorption. The results show that the ZIF-8/PAN nanofiber membrane has the characteristic peaks of XRD and FTIR, which are consistent with those of simulated ZIF-8. The specific surface area of ZIF-8/PAN nanofiber membrane increases from 13.5371 to 711.4171 m2 g−1 due to the introduction of ZIF-8 particles. The sensor using the nanofiber membrane as the gas sensing layer shows good response and linear correlation to different concentrations of acetone gas. The minimum detection limit of the sensor for acetone is 51.9 ppm. The blank control shows that the response of the sensor to acetone is mainly due to the introduction of ZIF-8 particles. In addition, the sensor also shows a good cyclic response to acetone.
Extremely high frequency Schottky diodes based on single GaN nanowires
Authors: Shugurov K Yu , Mozharov A M , Fedorov V V , Blokhin S A , Neplokh V V , Mukhin I S
Published: March 2023

Gallium nitride (GaN) is one of the most promising materials for high-frequency devices owing to its prominent material properties. We report on the fabrication and study of a series of Schottky diodes in the ground-signal-ground topology based on individual GaN nanowires. The electrical characterization of I–V curves demonstrated relatively high ideality factor value (about 6–9) in comparison to the planar Au/GaN diodes that can be attributed to the nanowire geometry. The effective barrier height in the studied structures was defined in the range of 0.25–0.4 eV. The small-signal frequency analysis was employed to study the dependency of the scattering parameters in the broad range from 0.1 to 40 GHz. The approximation fitting of the experimental data indicated the record high cutoff frequency of about 165.8 GHz.
Spectral techniques and mathematical aspects of K
4 chain graph
Authors: Yan Tao , Kosar Zunaira , Aslam Adnan , Zaman Shahid , Ullah Asad
Published: March 2023

The resistance distance between any two vertices of a connected graph is defined as the net effective resistance between them. An electrical network can be constructed from a graph by replacing each edge with a unit resistor. Resistance distances are computed by methods of the theory of resistive electrical networks (based on Ohm’s and Kirchhoff’s laws). The standard method to compute resistance distance is via the Moore-Penrose generalized inverse of the Laplacian matrix of the underlying graph G. In this article, we used the electric network approach and the combinatorial approach, to derive the exact expression for resistance distances between any two vertices of the

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ring model. By employing a recursive connection, firstly we determined all the eigenvalues and their multiplicities in relation to the corresponding Laplacian and normalised matrices. Secondly, we obtained the Kirchhoff index and multiplicative degree Kirchhoff index for

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. Finally, we calculated the mean first passage time and Kemeny constant of

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. Our computed results provide a comprehensive approach for exploring random walks on complex networks, especially biased random walks, which may also help to better understand and tackle some practical problems such as search and routing on networks.
Spin-charge-coupled transverse resistance in an ambipolar conductor YH2-based Hall-bar structure with perpendicularly magnetized current-injection electrodes
Authors: Sato Kaname , Takahashi Yutaro , Akisato Shujiro , Mikami Ryota , Suganuma Nao , Ashizawa Yugo , Kawaguchi Hayate , Nakajima Yoshikata , Ukai Tomofumi , Fuji Yasuhiko , Hanajiri Tatsuro , Kaneko Junya , Nakamura Osamu , Van Thach Pham , Awano Hiroyuki , Hasegawa Shigehiko , Sakai Masamichi
Published: March 2023

Spin-charge (SC) coupling is crucial in spintronics and the coupling mechanisms can be classified into bulk characteristic via spin-orbit interaction (SOI) or the interfacial characteristic provided by a junction formed by magnetic and nonmagnetic conductors. The two types of SC couplings account for the transverse resistance (TR) in a planer channel subjected to out-of-plane-polarized spin current injection. This is because interfacial spin-accumulation induces the diffusive transport of spin-angular momentum, which is converted into transverse charge accumulation via SOI. We explore the SC coupling characteristics of a lateral junction consisting of (i) a rare-earth transition metal (RE-TM) ferrimagnet with perpendicular magnetic anisotropy and (ii) a compensated metal, YH2, where electrons and holes simultaneously participate in spin and charge transports. This set-up allows us to observe the TR, which mirrors the magnetization of the RE-TM employed as the current-source electrode in the planer Hall-bar structure. The results show that the inverse spin Hall effect contributes significantly to the TR. Along with the TR measurement, we formulate a minimal expression of the TR when out-of-plane-polarized electron and hole spin currents are injected from the magnetic electrode. Since this formulation is independent of the details of the SC coupling mechanism, it is applied to interpret the observation result to reveal the SC coupling characteristics of the RE-TM and YH2 set-up.