bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-intrusive reduced-order model for time-dependent stochastic partial differential equations utilizing dynamic mode decomposition and polynomial chaos expansion
Authors: Wang Shuman , Batool Afshan , Sun Xiang , Pan Xiaomin
Published: July 2024

In this study, we present a novel non-intrusive reduced-order model (ROM) for solving time-dependent stochastic partial differential equations (SPDEs). Utilizing proper orthogonal decomposition (POD), we extract spatial modes from high-fidelity solutions. A dynamic mode decomposition (DMD) method is then applied to vertically stacked matrices of projection coefficients for future prediction of coefficient fields. Polynomial chaos expansion (PCE) is employed to construct a mapping from random parameter inputs to the DMD-predicted coefficient field. These lead to the POD–DMD–PCE method. The innovation lies in vertically stacking projection coefficients, ensuring time-dimensional consistency in the coefficient matrix for DMD and facilitating parameter integration for PCE analysis. This method combines the model reduction of POD with the time extrapolation strengths of DMD, effectively recovering field solutions both within and beyond the training time interval. The efficiency and time extrapolation capabilities of the proposed method are validated through various nonlinear SPDEs. These include a reaction–diffusion equation with 19 parameters, a two-dimensional heat equation with two parameters, and a one-dimensional Burgers equation with three parameters.
Valley contrasting chirality in triple Dirac points
Authors: Im Jonghyeok , Baitha Monu Nath , Kim Kyoungsik
Published: July 2024

The presented study suggests a silicon photonic topological insulator with triple Dirac points, each associated with a specific valley; there is a contrast in the chirality (handedness) of the photon states between these valleys. This contrasting chirality results in interesting optical properties, potentially leading to topologically protected robust wave guiding effect in compact structure with sharp edge.
A platform for planar dynamic compression of crystalline hydrogen toward the terapascal regime
Authors: Schwemmlein A. K. , Collins G. W. , LaPierre A. J. , Sprowal Z. K. , Polsin D. N. , Jeanloz R. , Celliers P. M. , Eggert J. H. , Rygg J. R.
Published: July 2024

We describe a method for laser-driven planar compression of crystalline hydrogen that starts with a sample of solid para-hydrogen (even-valued rotational quantum number j) having an entropy of 0.06 kB/molecule at 10 K and 2 atm, with Boltzmann constant kB. Starting with this low-entropy state, the sample is compressed using a small initial shock (<0.2 GPa), followed by a pressure ramp that approaches isentropic loading as the sample is taken to hundreds of GPa. Planar loading allows for quantitative compression measurements; the objective of our low-entropy compression is to keep the sample cold enough to characterize crystalline hydrogen toward the terapascal range.
Effects of wire size on electrical and shock-wave characteristics in underwater electrical explosions of aluminum wires
Authors: Zhang Shaojie , Chen Wansheng , Lu Yong , Zhang Yongmin , Wang Shuangming , Qiu Aici , Ma Liang , Gao Liang , Chen Fei
Published: July 2024

Initial wire resistance is an important parameter in an underwater electrical wire explosion because it directly affects the discharge characteristics of the circuit and indirectly affects the explosion and shock-wave generation. This paper presents a study on how the initial resistance affects electrical and shock-wave characteristics of underwater electrical explosions of aluminum wires with an initial energy storage of ∼53.5 kJ under the optimal mode. Load voltage, circuit current, and shock-wave pressure were recorded and analyzed. The experimental results show that the average of the discharge channel resistance and the total energy deposition all increase with the initial resistance. In addition, there is no simple functional relationship between the energy deposition during the phase transition process and the initial resistance, while the energy deposition during the plasma growth process increases with the initial resistance. As for shock waves at ∼33 cm, it is observed that when the initial resistance increases from 674.82 to 1581.60 μΩ, the peak pressure, energy density, and impulse increase from 12.65 MPa, 2.67 kJ/m2, and 964.51 Pa s to 42.37 MPa, 18.21 kJ/m2, and 1940.42 Pa s, respectively. In other words, for the optimal mode, an underwater electrical explosion with thinner and longer wire is more conducive to generating strong shock waves in the far-field regime. These results should help select loads for underwater electrical wire explosions in engineering applications.
Mechanics equilibrium in Tai-chi diagram
Authors: Dang Fei , Xiao Qingquan , Yang Pengfei
Published: July 2024

Tai chi culture has a widespread influence on the world. Tai-chi diagrams, as the symbol of Tai chi culture, express the balance between Yin and Yang through the centrosymmetric pattern, but the balance connotation of Tai-chi diagrams needs a comprehensive understanding in more aspects, e.g., the balance in mechanics. In this work, we propose a mechanics theory to investigate the intrinsic mechanism of Yin–Yang equilibrium in ancient and modern Tai-chi diagrams. The model based on the minimum potential energy theory can effectively describe the interface curves of the Yin–Yang equilibrium by modifying boundary conditions, which is proven by experiments. The results show that the balance of Tai-chi diagrams is not only manifested in its symmetrical appearance but also reflected in its intrinsic balance configuration in mechanics. The model presented herein provides a new perspective to understand the balance of Tai-chi diagrams, which may provide useful insights into the applications of Tai-chi diagrams.
Interaction of highly focused intense laser radiation with transparent dielectrics: Subwavelength nanogratings formation
Authors: Bogatskaya A. V. , Volkova E. A. , Popov A. M.
Published: July 2024

Femtosecond laser writing of birefringent subwavelength nanolattices in dielectrics has been studied for almost two decades since it reveals a number of applications for optical memory devices, optical waveguides, microfluidic channels, etc. In this work, a numerical study of the formation of plasma quasiperiodic nanostructures in a fused silica in the propagation direction of a focused laser pulse is carried out. It is shown that the focused beam creates a dense plasma, which provides an effective reflection of the incident laser pulse, leading to the formation of a standing wave. In the bundles of standing wave, an effective ionization emerges, which forms plasma gratings with a subwavelength period. The conducted modeling allows us to determine the conditions under which the proposed regime of material nanostructuring is possible. It is shown that the energy absorbed in plasma gratings will ensure the substance melting, which leads to the formation of “frozen” quasiperiodic nanopatterns.
Compton rocket effect due to the action of radiation reaction force in degenerate plasma
Authors: Berezhiani V. I. , Mahajan S. M.
Published: July 2024

A closed set of fluid equations with radiation reaction force (RRF) are constructed from the moments of the appropriate single particle kinetic equation describing a relativistic degenerate (high density) electron plasma. The closure, in analogy with the Maxwellian closure for non-degenerate plasmas, is affected via a parametrized Fermi-Dirac distribution. It is shown that the degeneracy increases RRF just as will be predicted from the so-called “Compton Rocket” effect.
Iterative modal reconstruction for sparse particle tracking data
Authors: Grille Guerra Adrian , Sciacchitano Andrea , Scarano Fulvio
Published: July 2024

A method to reconstruct the dense velocity field from relatively sparse particle tracks is introduced. The approach leverages the properties of proper orthogonal decomposition (POD), and it iteratively reconstructs the detailed spatial modes from a first, coarse estimation thereof. The initially coarse Cartesian representation of the velocity field is obtained by local data averaging, where POD is applied. The spatial resolution of the POD modes is enhanced by reprojecting them onto the sparse particle velocity to iteratively improve the reconstruction of the temporal coefficients. Finally, the enhanced velocity field is represented at high-resolution with a reduced order model using the dominant POD modes. The method is referred to as iterative modal reconstruction (IMR), as an extension of the recently proposed data-enhanced particle tracking velocimetry algorithm, introduced for cross correlation-based velocity data. Experiments in the wake of a cylinder at ReD = 27 000 are used to assess the suitability of the method to resolve the turbulent Kármán–Benard wake. The approach is benchmarked against traditional as well as state-of-the-art reconstruction methods, illustrating the capability of IMR of enhancing the spatial resolution of sparse velocity data.
Interband cascade light-emitting diodes grown on silicon substrates using GaSb buffer layer
Authors: Ince Fatih F. , Frost Mega , Shima Darryl , Rotter Thomas J. , Addamane Sadhvikas , McCartney Martha R. , Smith David J. , Canedy Chadwick L. , Tomasulo Stephanie , Kim Chul Soo , Bewley William W. , Vurgaftman Igor , Meyer Jerry R. , Balakrishnan Ganesh
Published: July 2024

Interband cascade light-emitting diodes (ICLEDs) offer attractive advantages for infrared applications, which would greatly expand if high-quality growth on silicon substrates could be achieved. This work describes the formation of threading dislocations in ICLEDs grown monolithically on GaSb-on-Silicon wafers. The epitaxial growth is done in two stages: the GaSb-on-Silicon buffer is grown first, followed by the ICLED growth. The buffer growth involves the nucleation of a 10-nm-thick AlSb buffer layer on the silicon surface, followed by the GaSb growth. The AlSb nucleation layer promotes the formation of 90° and 60° interfacial misfit dislocations, resulting in a highly planar morphology for subsequent GaSb growth that is almost 100% relaxed. The resulting GaSb buffer for growth of the ICLED has a threading dislocation density of ∼107/cm2 after ∼3 μm of growth. The fabricated LEDs showed variations in device performance, with some devices demonstrating comparable light–current–voltage curves to those for devices grown on GaSb substrates, while other devices showed somewhat reduced relative performance. Cross-sectional transmission electron microscopy observations of the inferior diodes indicated that the multiplication of threading dislocations in the active region had most likely caused the increased leakage current and lower output power. Enhanced defect filter layers on the GaSb/Si substrates should provide more consistent diode performance and a viable future growth approach for antimonide-based ICLEDs and other infrared devices.
Preparation and photocatalytic performance of BiOCl nanosheet–TiO2 nanotube array composites
Authors: Liu Yude , You Mengqin , Li Rui , Du Jun
Published: July 2024

Combining BiOCl with TiO2 nanomaterials is beneficial to enhance the photocatalytic activity and optoelectronic activity. In this paper, BiOCl nanosheet–TiO2 nanotube array composites were synthesized to enhance the photocatalytic degradation performance for methyl orange (MO) of TiO2 under ultraviolet light irradiation. BiOCl nanosheets were deposited on TiO2 nanotube arrays by the straightforward impregnation method. X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, and photocurrent (i–t) were used to evaluate the composites of BiOCl nanosheets–TiO2 nanotube arrays. The results showed that the tetragonal BiOCl nanosheets clustered together on the surface of the TiO2 nanotubes and grew along the (110) crystal plane. The composites outperformed pure TiO2 regarding outstanding structure and overall photocatalytic performance, and the MO photocatalytic degradation rate was 98.5%. For the 30-BiOCl–TiO2, its photocurrent intensity (58 µA) was 4.5 higher than TiO2 (13 µA). The degradation rate of 87% can still be reached after three cycles.
Integrative implementation of scattering reduction and radiation enhancement for an electrically small antenna by subwavelength plasmas
Authors: Chen Peiqi , Nie Qiuyue , Zhang Zhonglin , Lin Shu , Meng Zhuotao , Yan Changshi , Zhao Xingyu , Ai Xin , Wei Guoqiang , Shi Zhixin
Published: July 2024

The integrative design of scattering and radiation characteristics of antennas is of great practical significance for modern wireless communication. In this work, from the perspective of separate and cooperative modes, we comprehensively discussed the possibility of simultaneously and harmoniously implementing scattering suppression and radiation enhancement for an electrically small antenna by subwavelength plasmas. For the separate mode where the two functions are decoupled based on a two-layer structure, it is shown that an overdense–underdense core–shell density profile is preferred to achieve the optimal synergism between radiation enhancement and plasmonic-cloaking-induced invisibility, where the angular frequency of detecting waves (ωd) is supposed to be lower than that of communication signals (ωc). For the cooperative mode where the two functions are coupled within one plasma shell, the collaborative strategies between plasmonic-cloaking/Fano-resonance-induced invisibility and radiation enhancement are analyzed. The results show that the plasmonic-cloaking type requires ωd > ωc, while for the Fano-resonance type, ωd is larger/less than ωc when radiation enhancement is dominated by the symmetrically/asymmetrically coupled plasmon modes. Also, we provided clearer perspectives to distinguish the physical differences between plasmonic-cloaking and Fano-resonance-induced invisibility and between radiation enhancement underlying the two modes. Our results provide promising solutions for designing next-generation plasma-based tunable and intelligent stealth antennas.
Barrier crossing in a viscoelastic medium under active noise: Predictions of Kramers’ flux-over-population method
Authors: Cherayil Binny J.
Published: July 2024

The biochemical activity inside a cell has recently been suggested to act as a source of hydrodynamic fluctuations that can speed up or slow down enzyme catalysis [Tripathi et al., Commun. Phys. 5, 101 (2022).] The idea has been tested against and largely corroborated by simulations of activated barrier crossing in a simple fluid in the presence of thermal and athermal noise. The present paper attempts a wholly analytic solution to the same noise-driven barrier crossing problem but generalizes it to include viscoelastic memory effects of the kind likely to be present in cellular interiors. A calculation of the model’s barrier crossing rate, using Kramers’ flux-over-population formalism, reveals that in relation to the case where athermal noise is absent, athermal noise always accelerates barrier crossing, though the extent of enhancement depends on the duration τ0 over which the noise acts. More importantly, there exists a critical τ0—determined by the properties of the medium—at which Kramers’ theory breaks down and, on approach to which, the rate grows significantly. The possibility of such a giant enhancement is potentially open to experimental validation using optically trapped nanoparticles in viscoelastic media that are acted on by externally imposed colored noise.
Comparative analysis of fluctuations in viscoelastic stress: A comparison of the temporary network and dumbbell models
Authors: Winters Arturo , Öttinger Hans Christian , Vermant Jan
Published: July 2024

Traditionally, stress fluctuations in flowing and deformed materials are overlooked, with an obvious focus on average stresses in a continuum mechanical approximation. However, these fluctuations, often dismissed as “noise,” hold the potential to provide direct insights into the material structure and its structure-stress coupling, uncovering detailed aspects of fluid transport and relaxation behaviors. Despite advancements in experimental techniques allowing for the visualization of these fluctuations, their significance remains largely untapped as modeling efforts continue to target Newtonian fluids within the confines of Gaussian noise assumptions. In the present work, a comparative analysis of stress fluctuations in two distinct microstructural models is carried out: the temporary network model and the hydrodynamic dumbbell model. Despite both models conforming to the upper convected Maxwell model at a macroscopic level, the temporary network model predicts non-Gaussian fluctuations. We find that stress fluctuations within the temporary network model exhibit more pronounced abruptness at the local scale, with only an enlargement of the control volume leading to a gradual Gaussian-like noise, diminishing the differences between the two models. These findings underscore the heightened sensitivity of fluctuating rheology to microstructural details and the microstructure–flow coupling, beyond what is captured by macroscopically averaged stresses.
Flow-induced vibration of the drilling pipe with internal flow under the combination of control rods and rotation
Authors: Chen Wei , Bao Yanxu , Lin Yongshui , Zhang Xiaoyu , Shao Jiangyan , Dong Qin , Rheem Chang-Kyu , Wen Binrong , Li Xiaobin
Published: July 2024

The effect of a combination of control rods and rotations on the fluid induced vibration (FIV) response of pipes with internal flow is numerically investigated. A numerical simulation method for a pipe with internal flow was established according to a strip theory. The results show that the control rod arrangement does not change the vortex shedding on the noninternal flow pipe. As the rotation rate α increases, the pipe vortex layer is deflected, increasing the influence of the control rod. The pipe vortex shedding stops at α = 0.75, and the dimensionless cross-flow amplitude reduction (RAy) reaches 0.95. For the pipe with an internal flow velocity of V = 1 m/s, the vortex shedding stops earlier. As the α increases from 0 to 0.5, the RAy of noninternal flow pipe increases from 0.07 to 0.85. The internal flow has an enhanced effect on FIV suppression. The control rod–rotation combination provides more stable FIV suppression of the pipe than the two-dimensional elastically mounted cylinders.
Broken symmetries in quasi-2D charged systems via negative dielectric confinement
Authors: Gao Xuanzhao , Gan Zecheng
Published: July 2024

We report spontaneous symmetry breaking (SSB) phenomena in symmetrically charged binary particle systems under planar nanoconfinement with negative dielectric constants. The SSB is triggered solely via the dielectric confinement effect, without any external fields. The mechanism of SSB is found to be caused by the strong polarization field enhanced by nanoconfinement, giving rise to charge/field oscillations in the transverse directions. Interestingly, dielectric contrast can even determine the degree of SSB in transverse and longitudinal dimensions, forming charge-separated interfacial liquids and clusters on square lattices. Furthermore, we analytically show that the formed lattice constant is determined by the dielectric mismatch and the length scale of confinement, which is validated via molecular dynamics simulations. The novel broken symmetry mechanism may provide new insights into the study of quasi-2D systems and the design of future nanodevices.
Adiabatic theory of resonant particle dynamics with frequency chirping chorus waves in magnetospheric plasmas
Authors: Zheng Jiangshan , Wang Ge , Li Bo
Published: July 2024

We present the adiabatic regime for the particles interacting with the frequency chirping waves in the inhomogeneous magnetic field. Despite the rapid change of the parameters during the interaction, we can construct an adiabatic invariant with new canonical coordinates, which is shown to be conserved as long as the particles stay trapped in the reference frame moving with the resonance. Assuming the trapped particle distribution as a function of the adiabatic invariant and the water-bag approximation, we derive an analytic form of the nonlinear current as a function of the inhomogeneous parameter that describes the frequency chirping and inhomogeneities in the background magnetic field. The nonlinear current expression is also examined in the Vlasov hybrid simulations, and the simulation results show that the nonlinear current can be well described by the adiabatic water-bag approximation, except for the chirping onset stage and the source region where the adiabatic approximation is invalid.
Distinguishing homolytic vs heterolytic bond dissociation of phenylsulfonium cations with localized active space methods
Authors: Wang Qiaohong , Agarawal Valay , Hermes Matthew R. , Motta Mario , Rice Julia E. , Jones Gavin O. , Gagliardi Laura
Published: July 2024

Modeling chemical reactions with quantum chemical methods is challenging when the electronic structure varies significantly throughout the reaction and when electronic excited states are involved. Multireference methods, such as complete active space self-consistent field (CASSCF), can handle these multiconfigurational situations. However, even if the size of the needed active space is affordable, in many cases, the active space does not change consistently from reactant to product, causing discontinuities in the potential energy surface. The localized active space SCF (LASSCF) is a cheaper alternative to CASSCF for strongly correlated systems with weakly correlated fragments. The method is used for the first time to study a chemical reaction, namely the bond dissociation of a mono-, di-, and triphenylsulfonium cation. LASSCF calculations generate smooth potential energy scans more easily than the corresponding, more computationally expensive CASSCF calculations while predicting similar bond dissociation energies. Our calculations suggest a homolytic bond cleavage for di- and triphenylsulfonium and a heterolytic pathway for monophenylsulfonium.
Nontrivial effects of geometric and charge defects on one-dimensional confined water
Authors: Xue Minmin , Shen Chun , Zhang Zhuhua
Published: July 2024

Water confined within nanochannels with specific functionalities serves as the foundation for a variety of emerging nanofluidic applications. However, the structure and dynamics of the confined liquid are susceptibly influenced by practically hard-to-avoid defects, yet knowledge of this fact remains largely unexplored. Here, using extensive molecular dynamics simulations, we elucidate the significant influence of geometric and charge defects on one-dimensional confined water. We show that the two types of defects can both reshape the water density distribution by constraining the translocation of water molecules along the circumferential direction. In addition to structural alterations, collective translocation and rotation of water slabs arise during transportation under external pressure. Below the temperature threshold marking the initiation of liquid-solid transition, the geometric defect retards water diffusion through a pinning effect, while the charge defect induces an anti-freezing effect. The latter is attributed to the electrostatic interaction between the charge defect and water molecules that hinders the formation of a stable hydrogen bond network by disrupting molecular dipole orientation. Consequently, this behavior results in a reduction in the number and lifetime of hydrogen bonds within the phase transition interval. The distinct roles of the two types of defects could be utilized to control the structure and dynamics of confined liquids that may result in distinct functionalities for nanofluidic applications.
The anomalous Hall effect in the epitaxial-grown semiconducting CuCo2O4 thin film
Authors: Ji Xianghao , Zheng Biao , Xue Mingzhu , Liu Xue , Gao Wenshuai , Tian Mingliang , Chen Xuegang
Published: July 2024

The high-quality inverse spinel CuCo2O4 thin films are epitaxially grown on (001) MgAl2O4 substrates by radio frequency magnetron sputtering. The electrical transport properties exhibit typical semiconducting characteristics, accompanying the enhancement of resistivity with the thinning of CuCo2O4 thickness. The transport properties could be well understood by the Mott variable range hopping model. The anomalous Hall effect with a clear hysteresis loop is observed below 100 K, indicating the existence of out-of-plane magnetization in the epitaxial-grown CuCo2O4 films. In addition, the negative magnetoresistance at low temperature reverses to the positive magnetoresistance (≥100 K), which is related to the changes from the decrease in spin/carrier scattering under the magnetic field at low temperature to the enhancement of carrier deflection due to the conventional Lorenz force (≥100 K). The observed physical properties are closely related to the orbital occupation of Cu ion in CuCo2O4 films, which is a significant difference compared to that of documented metallic NiCo2O4. This work is a good comprehensive study of inverse spinel oxide thin films.
Strong microwave absorption of Fe-deficient SrFe9.4Cu0.8Sn0.5O19-d with enhanced permittivity and ferromagnetic resonance by high annealing temperature
Authors: Liu Bo , Li Lun , Li Kewei , Wang Xiaoqiong , Tan Yukun , Zhao Shifeng , Zhou Wenping , Xing Shuya , Yang Wenyun , Liu Shunquan , Chang Hong
Published: July 2024

The oxygen environments of Fe+3-δ ions determine the magnetic anisotropy of M-type ferrites. The high annealing temperature increases the oxygen content and decreases the lattice strain in M-type SrFe9.4Cu0.8Sn0.5O19-d ferrites. The anisotropic field and the coercive field decrease with the increasing annealing temperature. Annealed at 1400 °C, a ferromagnetic resonance is observed at the frequency above 9.5 GHz, with the real part having a peak and the imaginary part of the permeability having a high plateau over a wide frequency range. It enables the microwave energy' dissipation by the magnetic loss. Furthermore, the extra oxygen ions ease up the dipole polarizations' rotation and significantly increase the dielectric permittivity. At thin thickness of 1.3 mm, the effective absorption bandwidth (RL≤−10 dB) of SrFe9.4Cu0.8Sn0.5O19-d annealed at 1400 °C is 7.1+ GHz from 10.9 to 18+ GHz. SrFe9.4Cu0.6Sn0.6O19-d annealed at 1400 °C has the microwave absorption bandwidth of 8.8 GHz from 9.2 to 18+ GHz at 1.6 mm. Both are very promising microwave absorbing materials.
Chemical heterogeneity size effects at nanoscale on interface thermal resistance of solid–liquid polymer interface via molecular dynamics simulations
Authors: Luo Qing-Yao , Surblys Donatas , Matsubara Hiroki , Ohara Taku
Published: July 2024

The shrinking size of integrated chips poses thermal management challenges. Understanding the size effect of chemical heterogeneity on solid–liquid interfacial thermal transfer is essential for heterogeneous chip design, yet the underlying mechanisms remain lacking. The present work used the liquid n-alkanes as the thermal interface material between solid platinum substrates. To characterize chemical heterogeneity, periodic solid surface patterns composed of patches with alternating solid–liquid affinities were constructed. By using non-equilibrium molecular dynamics simulations, we investigated the size effect of chemically heterogeneous patterns on interfacial thermal resistance (ITR) at the nanoscale. At larger heterogeneity sizes, i.e., larger patch sizes, most alkane molecules directly in contact weak interaction patches cannot interact with strong interaction patches due to long atomic distances. In the case of alkanes in contact a cold substrate, alkanes in contact weak interaction patches transferred thermal energy to the substrate at a lower rate than those in contact strong interaction patches. The different rates resulted in the higher temperature of alkanes in contact weak interaction patches than those in contact strong interaction patches and, therefore, a larger disparity between temperature jump at the strong interaction areas and that at the weak interaction areas. The non-uniformity of temperature jump distribution increased ITR when compared to the heterogeneous surface system characterized by a smaller patch size with a more uniform temperature distribution in the plane perpendicular to the heat flux direction. In addition, the classical parallel thermal resistance model predicted ITR accurately for the heterogeneous surface systems with small size patches but overestimated overall thermal resistance.
Indigenous women thrive in Los Alamos internships
Authors: Feder Toni
Published: July 2024

A small program is having a big impact on its participants.
Sexual risk and testing for sexually transmissible infections in Aboriginal and Torres Strait Islander peoples and non-Indigenous young South Australians: results of an online survey
Authors: Harfield Stephen , Elliott Salenna , Barzi Federica , Minto Kiara , Dean Judith A. , Ward James
Published: July 2024

Background Disproportionate rates of sexually transmissible infections (STIs) among Aboriginal and Torres Strait Islander young people are often attributed to risk-taking behaviours, but research rarely conducts direct comparison with their non-Indigenous peers to address this negative discourse. Methods ‘Let’s Talk About It 2019’ was a cross-sectional online survey of South Australians (16–29 years). It prioritised recruitment of Aboriginal and Torres Strait Islander respondents to compare behaviours with non-Indigenous peers using multivariable Poisson regression models. Results Aboriginal and Torres Strait Islander (n = 231) and non-Indigenous (n = 2062) respondents reported similar condom use (40% vs 43%, P = 0.477) and sexual debut median ages (16 years vs 17 years). Higher proportions of Aboriginal and/or Torres Strait Islander respondents reported a recent health check (48% vs 38%, P = 0.002), STIs (60% vs 49%, P < 0.001) and HIV (37% vs 28%, P = 0.006) testing, STI diagnosis (29% vs 21%, P = 0.042), and intoxication during last sex (30% vs 18%, P < 0.001). Conclusions Behaviours associated with STI transmission were mostly similar among Aboriginal and Torres Strait Islander and non-Indigenous respondents. Higher STI/HIV testing among Aboriginal and Torres Strait Islander respondents suggests effectiveness of targeted programs. Interventions targeting substance use and condom use among all young people are needed. Future interventions need to focus beyond behaviours and explore social determinants of health and sexual networks as contributors to disproportionate STI rates.
A force-sensitive mutation reveals a non-canonical role for dynein in anaphase progression
Authors: Salvador-Garcia David , Jin Li , Hensley Andrew , Gölcük Mert , Gallaud Emmanuel , Chaaban Sami , Port Fillip , Vagnoni Alessio , Planelles-Herrero Vicente José , McClintock Mark A. , Derivery Emmanuel , Carter Andrew P. , Giet Régis , Gür Mert , Yildiz Ahmet , Bullock Simon L.
Published: July 2024

The diverse roles of the dynein motor in shaping microtubule networks and cargo transport complicate in vivo analysis of its functions significantly. To address this issue, we have generated a series of missense mutations in Drosophila Dynein heavy chain. We show that mutations associated with human neurological disease cause a range of defects, including impaired cargo trafficking in neurons. We also describe a novel microtubule-binding domain mutation that specifically blocks the metaphase–anaphase transition during mitosis in the embryo. This effect is independent from dynein’s canonical role in silencing the spindle assembly checkpoint. Optical trapping of purified dynein complexes reveals that this mutation only compromises motor performance under load, a finding rationalized by the results of all-atom molecular dynamics simulations. We propose that dynein has a novel function in anaphase progression that depends on it operating in a specific load regime. More broadly, our work illustrates how in vivo functions of motors can be dissected by manipulating their mechanical properties.
The interface of gravity and dark energy
Authors: Lackeos Kristen , Lieu Richard
Published: July 2024

At sufficiently large radii dark energy modifies the behavior of (a) bound orbits around a galaxy and (b) virialized gas in a cluster of galaxies. Dark energy also provides a natural cutoff to a cluster’s dark matter halo. In (a) there exists a maximum circular orbit beyond which periodic motion is no longer possible, and orbital evolution near critical binding is analytically calculable using an adiabatic invariant integral. The finding implicates the study of wide galaxy pairs. In (b), dark energy necessitates the use of a generalized Virial Theorem to describe gas at the outskirts of a cluster. When coupled to the baryonic escape condition, aided by dark energy, the results is a radius beyond which the continued establishment of a hydrostatic halo of thermalized baryons is untenable. This leads to a theoretically motivated virial radius. We use this theory to probe the structure of a cluster’s baryonic halo and apply it to X-ray and weak-lensing data collected on cluster Abell 1835. We find that gas in its outskirts deviates significantly from hydrostatic equilibrium beginning at

∼

1.3
 
Mpc

, the ‘inner’ virial radius. We also define a model dependent dark matter halo cutoff radius to A1835. The dark matter cutoff gives an upper limit to the cluster’s total mass of

∼

7
×

10

15

M

⊙

. Moreover, it is possible to derive an ‘outer’ hydrostatic equilibrium cutoff radius given a dark matter cutoff radius. A region of cluster gas transport and turbulence occurs between the inner and outer cutoff radii.
Evaluation of the performance of digital x-ray systems in pelvis radiography
Authors: Jreije Antonio , Krynke Leonid , Gricienė Birutė , Rimkus Bernardas , Dementavičienė Jūratė , Skovorodko Kirill
Published: July 2024

The aim of this study was to investigate the performance of eight digital radiography systems and to optimise the dose-image quality relationship for digital pelvis radiography. The study involved eight digital radiography systems used for general examinations at Vilnius University Hospital Santaros Klinikos. An anthropomorphic pelvic phantom (CIRS, US) was used to simulate a patient undergoing clinical pelvis radiography. Dose quantities entrance surface dose, dose area product (DAP) and exposure parameters (kVp, mA, mAs) were measured and the effects on the images were evaluated, considering physical contrast to noise ratio (CNR) and observer-based evaluations as image quality metrics. Increasing the tube voltage by 5 kVp from standard protocol led to a reduction in radiation dose (DAP) by 12%–20% with a slight impact on image quality (CNR decreases by 2%–10%). There was an inter-observer variability in image rating across different equipment (kappa value between 0 and 0.3); however, both observers agreed that increasing kVp up to 85–90 kV had no effect on perceived image quality. The results indicate that optimisation strategies should be tailored specifically for each x-ray system since significant performance differences and wide variations in radiation dose exist across various digital radiography systems used in clinical settings. The use of high kVp can be used for dose optimisation in digital pelvis radiography without compromising image diagnostic accuracy.
Persistent and anti-persistent motion in bounded and unbounded space: resolution of the first-passage problem
Authors: Marris Daniel , Giuggioli Luca
Published: July 2024

The presence of temporal correlations in random movement trajectories is a widespread phenomenon across biological, chemical and physical systems. The ubiquity of persistent and anti-persistent motion in many natural and synthetic systems has led to a large literature on the modelling of temporally correlated movement paths. Despite the substantial body of work, little progress has been made to determine the dynamical properties of various transport related quantities, including the first-passage or first-hitting probability to one or multiple absorbing targets when space is bounded. To bridge this knowledge gap we generalise the renewal theory of first-passage and splitting probabilities to correlated discrete variables. We do so in arbitrary dimensions on a lattice for the so-called correlated or persistent random walk, the one step non-Markovian extension of the simple lattice random walk in bounded and unbounded space. We focus on bounded domains and consider both persistent and anti-persistent motion in hypercubic lattices as well as the hexagonal lattice. The discrete formalism allows us to extend the notion of the first-passage to that of the directional first-passage, whereby the walker must reach the target from a prescribed direction for a hitting event to occur. As an application to spatio-temporal observations of correlated moving cells that may be either repelled or attracted to hard surfaces, we compare the first-passage statistics to a target within a reflecting domain depending on whether an interaction with the reflective interface invokes a reversal of the movement direction or not. With strong persistence we observe multi-modality in the first-passage distribution in the former case, which instead is greatly suppressed in the latter.
Electron-scale turbulence characteristics with varying electron temperature gradient in LHD
Authors: Nasu T. , Tokuzawa T. , Nakata M. , Ida K. , Inagaki S. , Nishiura M. , Yoshimura Y. , Yanai R. , Tanaka K. , Yoshinuma M. , Kobayashi T. , Ejiri A. , Watanabe K.Y. , Yamada I. ,   LHD Experiment Group
Published: July 2024

Electron-scale turbulence, whose wavelength is the electron Larmor radius, is thought to have the potential to cause stiffness in an electron temperature gradient and degrade the confinement of future burning plasma in which the electron heating by alpha particles is dominant. The dependence of electron-scale turbulence and electron heat flux on the electron temperature inverse gradient length

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, were investigated. The electron temperature gradient was successfully varied in the range of

−
3
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ax

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<
12

by controlling the injection power of on/off-axis electron cyclotron heating. The results show a significant increase in the electron-scale turbulence with increasing

R
ax

/

L

T
e

, especially in conditions where Electron Temperature Gradient (ETG) instability is linearly unstable, suggesting the presence of ETG turbulence at high

R
ax

/

L

T
e

. The electron heat flux also increases steeply with increasing

R
ax

/

L

T
e

. In addition, the electron-scale turbulence is observed even at

R
ax

/

L

T
e

∼
0

, which is stable in linear GKV calculations. Finding the cause of this phenomenon is an interesting task for the future.
Summary of the 11th Conference on Magnetic Confined Fusion Theory and Simulation
Authors: HAO 郝 Guangzhou 广周 , XU 许 Jianqiang 健强 , SUN 孙 Youwen 有文 , GUO 郭 Zhibin 志彬
Published: July 2024

This conference report summarizes recent progress in plasma theory and simulation that was presented in contributed papers and discussions at the 11th Conference on Magnetic Confined Fusion Theory and Simulation (CMCFTS) held in Chengdu, China, 27–30 October, 2023. Progress in various fields has been achieved. For example, results on zonal flow generation by mode coupling, simulations of the key physics of divertor detachment, energetic particle effects on magnetohydrodynamic (MHD) modes in addition to ion- and electron-scale turbulence, physics of edge coherent modes and edge-localized modes, and the optimization of ion heating schemes as well as confinement scenarios using advanced integrated modeling are presented at the conference. In this conference, the scientific research groups were organized into six categories: (a) edge and divertor physics; (b) impurity, heating, and current drive; (c) energetic particle physics; (d) turbulent transport; (e) MHD instability; and (f) integrated modeling and code development. A summary of the highlighted progress in these working groups is presented.
On noncommutative differential forms
Authors: Tsygan Boris
Published: July 2024

We review the topic of noncommutative differential forms, following the works of Karoubi, Cuntz–Quillen, Cortiñas, Ginzburg–Schedler, and Waikit Yeung. In particular we give a new proof of the theorem of Ginzburg and Schedler that compares extended noncommutative De Rham cohomology to cyclic homology. This theorem is a stronger version of a theorem of Karoubi. We also describe an algebraic structure, namely a category in DG cocategories, that noncommutative forms and other versions of noncommutative calculus are particular cases of.
Nehru
Authors: Panagariya Arvind
Published: July 2024

It is widely believed that Nehru embraced Fabian socialism while studying in Cambridge and London. This is an entirely erroneous impression. His conversion to any form of socialism did not occur until he visited England again in 1927, with a stop in the Soviet Union on the way back. At this time, he became a radical socialist, bordering communist. The chapter amasses a wealth of evidence showing this evolution. In all likelihood, it was during the deliberations of the National Planning Committee of Congress that he began shifting to a more moderate form of socialism, principally because of the pushback by the leading industrialists who were also members of the committee. This shift eventually led him to opt for the mixed economy model in which private and public sectors operated side by side.
The Nehru Development Model
Authors: Panagariya Arvind
Published: July 2024

Nehru must be credited with the design of the economic policy framework that India adopted after independence. As such, it is entirely appropriate to label the model India adopted as the Nehru Development Model. Objectives Nehru set out for himself were the removal of poverty, self-sufficiency, and socialism. The strategy to achieve these objectives consisted of the development of heavy industry upfront to maximize long-run growth, small-scale industry to generate employment and production of consumer goods, agriculture to ensure the supply of food, and minimum reliance on international trade. Policy instruments deployed included public-sector control of the commanding heights of the industry, control of private-sector investment through licensing, import licensing, price and distribution controls, and the creation of institutions of technical education. The chapter systematically documents these facts by reference to the writings and speeches of Nehru.
Export and Foreign Investment Policies
Authors: Panagariya Arvind
Published: July 2024

Until the sterling balances ran out, policymakers not only neglected exports but actively restricted them through export controls, export taxes on the major commodities, and anti-export domestic policies. The result was that India lost the opportunity to capture the space vacated by the United States and the United Kingdom in the world cotton textiles export market to Japan. After 1957, the need for export revenues was progressively recognized, but available fiscal resources to stimulate exports proved inadequate in the absence of devaluation. In contrast to his stance on the import and export policies, Nehru pursued a remarkably liberal foreign investment policy. He was keen on the rapid expansion of the public sector, but he was keener still on growth to eradicate India’s poverty. Therefore, when faced with a conflict between the expansion of the public sector and growth, he opted for the latter. Accordingly, his policy accommodated the private sector and, likewise, the foreign capital inflows.
The Political Leadership I
Authors: Panagariya Arvind
Published: July 2024

Nehru’s socialism became integral to the thinking of the influential politicians who survived him. None of them publicly challenged the essential elements of his model. Lal Bahadur Shastri, who succeeded him, is believed to have lacked enthusiasm for the heavy industry but never mentioned it in his speeches. He died in 1966 and was succeeded by Indira Gandhi, who happened to be more socialist than Nehru, her father. In a power struggle with the conservative wing of Congress, she scored a decisive victory by painting them as the friends of the big business. Subsequently, the nationalization of the major banks, insurance, coal, and energy companies only increased her popularity. Although her rival Morarji Desai was able to gain power in 1977, his policies were hardly different from hers. She returned to power in 1980, and until the end of 1984, when she was assassinated, the grip of socialism on the economy remained tight.
Economists and Other Policy Analysts
Authors: Panagariya Arvind
Published: July 2024

This chapter considers the impact of socialism on policy analysts, particularly economists. Remarkably, economists trained and raised in India have remained wedded to the socialist ideology even after the launch of the 1991 economic reforms. Until the mid-1980s, it was rare to come across any reform advocates from within India. Even in the mid-1980s, it was a tiny group of economists who had spent time abroad and worked inside the government that began pushing for baby steps toward liberalization. Though reform advocacy is no longer a lonely affair as it was even a decade ago, it remains the case that locally trained professional economists with a consistent record of advocacy of pro-market reforms are rare. For their part, leading Indian universities, including the Jawaharlal Nehru University, Delhi University, and Ashoka University, continue to be dominated by left or left-leaning economists.
Introduction
Authors: Antony Alexander K , Thompson William R
Published: July 2024

This chapter discusses the interplay between peace and transition. It highlights the significance of de-agrarianization in understanding the issue of contemporary war and peace. The democratic peace, the capitalist peace, economic interdependence, and boundary settlement or territorial peace are linked to the transition from the dominance of agricultural strategies to the dominance of industrial strategies in various ways. The chapter then looks into the alternative ways of examining the emergence of zones of peace. It provides an overview of the industrialization transition, which has not been operating universally as it diffused unevenly across the work after its origins in Western Europe.
A Dyadic Perspective
Authors: Antony Alexander K , Thompson William R
Published: July 2024

This chapter presents a dyadic perspective on research programs focused on the interdependence of industrialization, democratization, capitalism, and border settlements. It discusses all four explanatory foci simultaneously in two iterations, which starts with how the industrialization transition is based on the percentage of a state’s labor force that is involved in non-agricultural economic activity. The other iteration involves the capitalist peace literature exhibiting less consensus about how best to measure change in the international political economy. The chapter also presents the results of Granger-causality tests for the relationships among industrialization transition, democracy, trade openness, and border settlement. It considers the decline of some types of interstate warfare.
More Measurement Issues for Diffusion, Zones of Peace, and Network Effects
Authors: Antony Alexander K , Thompson William R
Published: July 2024

This chapter tackles the measurement issues for diffusion, zones of peace, and network effects. The measurement of zones involves the identification of discrete regions according to the designation of the United Nations and the accounting of state neighborhoods based on their local environment. Moreover, measuring various zones of peace requires examining the overall pattern of structural relations between a state and the other actors in its neighborhood. The chapter then enumerates conflict zones, negative peace zones, positive peace zones, and security communities as the four neighborhood conflict and peace gradations identified in which a state can be located. It then details how to examine the influence of the neighborhood environment while using large-N, quantitative methods.