bluuebunny/crossref_metadata_2025 huggingface dataset:
Strongly non-linear Boussinesq-type model of the dynamics of internal solitary waves propagating in a multilayer stratified fluid
Authors: Chesnokov A. A. , Ermishina V. E. , Liapidevskii V. Yu.
Published: July 2023

We propose a system of first-order balance laws that describe the propagation of internal solitary waves in a multilayer stratified shallow water with non-hydrostatic pressure in the upper and lower layers. The construction of this model is based on the use of additional variables, which make it possible to approximate the Green–Naghdi-type dispersive equations by a first-order system. In the Boussinesq approximation, the governing equations allow one to simulate the propagation of non-linear internal waves, taking into account fine density stratification, a weak velocity shear in the layers, and uneven topography. We obtain smooth steady-state soliton-like solutions of the proposed model in the form of symmetric and non-symmetric waves of mode-2 adjoining to a given multilayer constant flow. Numerical calculations of the generation and propagation of large-amplitude internal waves are carried out using both the proposed first-order system and Green–Naghdi-type equations. It is established that the solutions of these models practically coincide. The advantage of the first-order equations is the simplicity of numerical implementation and a significant reduction in the calculation time. We show that the results of numerical simulation are in good agreement with the experimental data on the evolution of mode-2 solitary waves in tanks of constant and variable height.
The invariance and distortion of vectorial light across a real-world free space link
Authors: Peters Cade , Cox Mitchell , Drozdov Alice , Forbes Andrew
Published: July 2023

Vectorial structured light, where the polarization is inhomogeneously distributed in space, has found a myriad of applications in both 2D and 3D optical fields. Here, we present an experimental study of the invariance and distortion of vectorial light through a real-world medium of atmospheric turbulence. We show that the amplitude and polarization structure are both severely distorted by the turbulent medium, yet the non-separability of these two degrees of freedom remains invariant. We monitor this invariance under a range of beam types and atmospheric conditions, over extended time periods, revealing the unitary nature of atmospheric turbulence in our experiment. Our results provide conclusive evidence that invariance and distortion are not mutually exclusive and that the degree of classical entanglement remains unaltered through such channels, and will be of interest to the large community interested in classical and quantum communication in free space.
Impact of surface preparation on the epitaxial growth of SrTiO3 on ScAlN/GaN heterostructures
Authors: Jin Eric N. , Lang Andrew C. , Downey Brian P. , Gokhale Vikrant J. , Hardy Matthew T. , Nepal Neeraj , Katzer D. Scott , Wheeler Virginia D.
Published: July 2023

Heterogeneous integration of functional oxides with ultra-wide bandgap (UWBG) semiconductors is desired for the realization of novel hybrid systems applicable to a wide array of commercial electronics and defense applications. In this work, we demonstrate the growth of crystalline SrTiO3 (STO) thin films on high-electron-mobility transistor (HEMT) heterostructures based on an emergent UWBG semiconductor ScAlN, used as the barrier layer on a GaN channel, and determine the effects of the pre-growth chemical treatments of the ScAlN surface on resultant heterostructure properties. We investigate wet chemical cleans of ScAlN with solvents, piranha solution, UV ozone and hydrofluoric acid, and a sulfuric-phosphoric acid mix prior to STO growth, and show that the commonly used piranha solution degrades the ScAlN surface, thereby reducing the crystal quality of the deposited STO layers and lowering the channel mobility. We determine that among the treatments studied, the solvent and sulfuric-phosphoric acid cleans were the least disruptive to the electrical properties of the GaN channel as evidenced from Hall effect measurements, but the sulfuric-phosphoric acid clean results in best oxide crystallinity, as determined from structural characterizations. We perform transmission electron microscopy imaging on the piranha-treated and sulfuric-phosphoric-treated samples to compare the microstructure and find that while intermixing occurs at the oxide-nitride interfaces for both samples, the interface roughness is lower and the STO grain size is larger in the sample with sulfuric-phosphoric acid treatment. This work demonstrates the first epitaxial growth of STO on an UWBG semiconductor and motivates STO/ScAlN/GaN as material platforms for high-frequency, high-power-density HEMTs.
2D shape reconstruction of submillimetric irregular rough particles from speckle pattern in interferometric particle imaging measurement
Authors: Fu Yushi , Zhang Hongxia , Hou Jinghui , Jia Dagong , Liu Tiegen
Published: July 2023

Particle shape is a significant feature of irregular particles. The interferometric particle imaging (IPI) technique has been introduced to retrieve submillimetric irregular rough particle shapes, while inevitable experimental noises hinder the convergence of two-dimensional (2D) particle shapes from single speckle patterns. In this work, a hybrid input–output algorithm with shrink-wrap support and oversampling smoothness constraints is utilized to suppress the Poisson noise in IPI measurement and recover accurate 2D shapes of particles. Our method is tested in numerical simulations on ice crystal shapes and actual IPI measurements on four different types of irregular, rough particles. The shape similarity of the reconstructed 2D shape has reached an average Jaccard Index score of 0.927, and the relative deviation of the reconstructed size is within 7% for all 60 tested irregular particles at the maximum shot noise level of 7.4%. Furthermore, our method has obviously reduced the uncertainty in the 3D shape reconstruction of irregular, rough particles.
A new vibratory response-based method for determining the optimal assembly tightening torque of the high-frequency piezoelectric ultrasonic transducer
Authors: Zhang Hongjie , Liu Xiaochen , Cai Yangchun , Wu Chuanhao , Gao Xinyue
Published: July 2023

Pre-tightening torque has a significant impact on the performance of a bolt-clamped high-frequency piezoelectric ultrasonic transducer widely used in wire bonding. To develop a vibratory response-based method for the determination of optimal pre-tightening torque, the vibration amplitude signals of the transducer under different excitation conditions were monitored, and the characteristic parameters of the response, involving the resonance frequency, settling time within the initial transient response, and vibration amplitude of the steady-state stage, were extracted. Based on a series of in-depth tests, analyses, and discussions, the influences that the pre-tightening torque has on the vibratory response properties were investigated. Then, the experimental measurement and the random forest method were combined to determine the optimal pre-tightening torque. The performance test results show that the developed method can give the optimal pre-tightening torque according to the desired vibrational response properties, and it is feasible, effective, and reliable as well as improves the adaptability and flexibility of the high-frequency ultrasonic transducer in the application.
Extended dissipaton equation of motion for electronic open quantum systems: Application to the Kondo impurity model
Authors: Su Yu , Chen Zi-Hao , Wang Yao , Zheng Xiao , Xu Rui-Xue , Yan YiJing
Published: July 2023

In this paper, we present an extended dissipaton equation of motion for studying the dynamics of electronic impurity systems. Compared with the original theoretical formalism, the quadratic couplings are introduced into the Hamiltonian accounting for the interaction between the impurity and its surrounding environment. By exploiting the quadratic fermionic dissipaton algebra, the proposed extended dissipaton equation of motion offers a powerful tool for studying the dynamical behaviors of electronic impurity systems, particularly in situations where nonequilibrium and strongly correlated effects play significant roles. Numerical demonstrations are carried out to investigate the temperature dependence of the Kondo resonance in the Kondo impurity model.
The three kingdoms—Photoinduced electron transfer cascades controlled by electronic couplings
Authors: Yang Guangjun , Shillito Georgina E. , Zens Clara , Dietzek-Ivanšić Benjamin , Kupfer Stephan
Published: July 2023

Excited states are the key species in photocatalysis, while the critical parameters that govern their applications are (i) excitation energy, (ii) accessibility, and (iii) lifetime. However, in molecular transition metal-based photosensitizers, there is a design tension between the creation of long-lived excited (triplet), e.g., metal-to-ligand charge transfer (3MLCT) states and the population of such states. Long-lived triplet states have low spin–orbit coupling (SOC) and hence their population is low. Thus, a long-lived triplet state can be populated but inefficiently. If the SOC is increased, the triplet state population efficiency is improved—coming at the cost of decreasing the lifetime. A promising strategy to isolate the triplet excited state away from the metal after intersystem crossing (ISC) involves the combination of transition metal complex and an organic donor/acceptor group. Here, we elucidate the excited state branching processes in a series of Ru(II)-terpyridyl push–pull triads by quantum chemical simulations. Scalar-relativistic time-dependent density theory simulations reveal that efficient ISC takes place along 1/3MLCT gateway states. Subsequently, competitive electron transfer (ET) pathways involving the organic chromophore, i.e., 10-methylphenothiazinyl and the terpyridyl ligands are available. The kinetics of the underlying ET processes were investigated within the semiclassical Marcus picture and along efficient internal reaction coordinates that connect the respective photoredox intermediates. The key parameter that governs the population transfer away from the metal toward the organic chromophore either by means of ligand-to-ligand (3LLCT; weakly coupled) or intra-ligand charge transfer (3ILCT; strongly coupled) states was determined to be the magnitude of the involved electronic coupling.
Ultrahigh vacuum pressure measurement using magneto-optical trap on atom chip
Authors: Supakar S. , Singh Vivek , Tiwari V. B. , Mishra S. R.
Published: July 2023

In this work, the UHV background pressure as low as 1.1×10−10 Torr has been measured using the loss rate characteristics of a vapor-loaded magneto-optical trap (MOT) formed on an atom chip in a UHV chamber. The loss rate due to non-rubidium (Rb) gases in the background in the chamber has been estimated by operating the MOT in low cooling beam intensities and low Rb pressure regimes simultaneously. Using this approach, we minimized the contributions of the intra-trap collisions as well as background MOT species collisions to the measured trap loss rate in our setup. These results can be useful for development of cold-atom based UHV pressure standards.
Assessment of the aerodynamic benefits of collocating horizontal- and vertical-axis wind turbines in tandem using actuator line model
Authors: Shao Yixiao , Su Jie , Tu Yu , Kuang Limin , Han Zhaolong , Zhang Kai , Zhou Dai
Published: July 2023

The actuator line model is used to study the vertically staggered wind turbine cluster composed of horizontal- and vertical-axis wind turbines (HAWTs and VAWTs) in a tandem layout. We consider three simple configurations, including VAWT upwind of HAWT (V + H), VAWT downwind of HAWT (H + V), and VAWT between the two HAWTs (H + V + H). A VAWT installed upwind of the HAWT can not only generate power by itself but can also enhance the power generation of the HAWT, and the total power increases by about 100 kW. When installed downstream the HAWT, the presence of the VAWT slightly reduces the power generation efficiency of the HAWT. However, the VAWT utilizes the increased wind speed between the HAWT and the ground and generates more power. The total power increases by about 60 kW. When installed between the two HAWTs, the beneficial effects of the VAWT on the downstream HAWT are not manifested. Nevertheless, the wind turbine cluster still generates 50 kW more power than that without the VAWT. Overall, even in the tandem layout where the wake effects are most pronounced, the collocation of VAWTs can still utilize the otherwise wasted wind resources, thus increasing the power generation density of wind farms.
Doubling the period in a turbulent pulsating flow
Authors: Nikitin Nikolay , Startsev Nikolay
Published: July 2023

In this work, a numerical study of pulsating turbulent flows in pipes of round and square cross sections was carried out. The bulk flow velocity changes proportionally to 1+β sin (ωt) at β  = 1. For all studied values of the Reynolds number from Re = 4000 to Re = 8000, it was found that for small periods T=2π/ω of flow oscillations, the mean characteristics of turbulence change periodically in time with a period of T, and at large values of T, the flow becomes laminar. The most interesting thing is that at intermediate values of T, the turbulence characteristics change periodically in time, but with a period twice as long as the period of flow oscillations.
Spectral characteristic of multi-wavelength random fiber laser using a microfiber knot resonator
Authors: Shen Ming , Li Yanxin , Li Qianying , Shu Xuewen
Published: July 2023

We demonstrate a U-band multi-wavelength random Raman fiber laser (RRFL) based on a microfiber knot resonator (MKR). The RRFL has a forward-pump half-open cavity, wherein a 10-km single mode fiber provides both Rayleigh backscattering feedback and Raman gain. A MKR with a 0.18 nm free spectral range is used as the broadband comb filter. Up to 40 and 38 wavelength channels within 3 dB bandwidth were achieved from the intracavity and the end of the RRFL, respectively. The laser showed a good stability with maximum 0.38 and 0.1 dB peak power fluctuation within an hour at the two outputs, respectively. The spectral evolution with two envelopes was observed, and the impact of the MKR was discussed. The MKR is a small-size all-fiber and wavelength-insensitive broadband filter, which suits well with the broadband operation of the RRFL. The proposed RRFL has a simple structure and good potential tunability and provides guidance for flexible multi-wavelength lasers in the U-band and other wavebands, which have great potential in applications.
Comparison of soil analytical methods for estimating plant-available potassium in highly weathered soils
Authors: Cheng Miaomiao , Bell Richard , Brown Jordan , Ma Qifu , Scanlan Craig
Published: July 2023

Context The NaHCO3-extractable soil K test (Colwell K) is the most frequently used method for soil K across Australia, but there is still uncertainty about the suitability of K testing guidelines for heavy-textured soils. Aims To determine whether Colwell K is suitable for predicting plant-available K on loam- and clay-textured soil types developed from highly weathered soil parent materials in Western Australia (WA). Methods Nine soil K testing methods were used to determine plant-available K on 21 soil types with a wide range of properties collected from three depths on the northern, central and southern farmlands in WA. Key results Quartz and K-feldspars were the dominant minerals in all soils, while limited white mica (1–2%) was identified in less than 10% of samples. The amount of K extracted by silver thiourea was only about 70% of the amounts extracted by NaHCO3 (Colwell K) and NH4OAc. Soil non-exchangeable K extracted by nitric acid and sodium tetraphenyl borate were from similar K pools, while aqua regia K was 1–6 times higher than these values. Conclusion There was no systemic difference or proportional bias between NH4OAc K and Colwell K, and both had good model performance (R2 > 0.86) for total K uptake by wheat in a single growing season in a wide range of soils. Implication In this diverse range of soils formed from weathered parent materials, the reliance on exchangeable K for plant K uptake suggests that plant-available K will be vulnerable to rundown due to negative K balances.
Elevated atmospheric CO
2
drove an increase in tropical cyclone intensity during the early Toarcian hyperthermal
Authors: Yan Qing , Li Xiang , Kemp David B. , Guo Jiaqi , Zhang Zhongshi , Hu Yongyun
Published: July 2023

The occurrence of sedimentary storm deposits around the Tethys Ocean during the early Toarcian hyperthermal (~183 Ma) suggests that intensified tropical cyclone (TC) activity occurred in response to CO
2
rise and marked warming. However, this hypothesized linkage between extreme warmth and storm activity remains untested, and the spatial pattern of any changes in TCs is unclear. Here, model results show that there were two potential storm genesis centers over Tethys during the early Toarcian hyperthermal located around the northwestern and southeastern Tethys. The empirically determined doubling of CO
2
concentration that accompanied the early Toarcian hyperthermal (~500 to ~1,000 ppmv) leads to increased probability of stronger storms over Tethys, in tandem with more favorable conditions for coastal erosion. These results match well with the geological occurrence of storm deposits during the early Toarcian hyperthermal and confirm that increased TC intensity would have accompanied global warming.
Inflammatory and tolerogenic myeloid cells determine outcome following human allergen challenge
Authors: Voskamp Astrid L. , Tak Tamar , Gerdes Maarten L. , Menafra Roberta , Duijster Ellen , Jochems Simon P. , Kielbasa Szymon M. , Kormelink Tom Groot , Stam Koen A. , van Hengel Oscar R.J. , de Jong Nicolette W. , Hendriks Rudi W. , Kloet Susan L. , Yazdanbakhsh Maria , de Jong Esther C. , Gerth van Wijk Roy , Smits Hermelijn H.
Published: July 2023

Innate mononuclear phagocytic system (MPS) cells preserve mucosal immune homeostasis. We investigated their role at nasal mucosa following allergen challenge with house dust mite. We combined single-cell proteome and transcriptome profiling on nasal immune cells from nasal biopsies cells from 30 allergic rhinitis and 27 non-allergic subjects before and after repeated nasal allergen challenge. Biopsies of patients showed infiltrating inflammatory HLA-DRhi/CD14+ and CD16+ monocytes and proallergic transcriptional changes in resident CD1C+/CD1A+ conventional dendritic cells (cDC)2 following challenge. In contrast, non-allergic individuals displayed distinct innate MPS responses to allergen challenge: predominant infiltration of myeloid-derived suppressor cells (MDSC: HLA-DRlow/CD14+ monocytes) and cDC2 expressing inhibitory/tolerogenic transcripts. These divergent patterns were confirmed in ex vivo stimulated MPS nasal biopsy cells. Thus, we identified not only MPS cell clusters involved in airway allergic inflammation but also highlight novel roles for non-inflammatory innate MPS responses by MDSC to allergens in non-allergic individuals. Future therapies should address MDSC activity as treatment for inflammatory airway diseases.
Angular correlations on causally-coherent inflationary horizons
Authors: Hogan Craig , Meyer Stephan S , Selub Nathaniel , Wehlen Frederick
Published: July 2023

We develop a model for correlations of cosmic microwave background (CMB) anisotropy on the largest angular scales, based on standard causal geometrical relationships in slow-roll inflation. Unlike standard models based on quantized field modes, it describes perturbations with nonlocal directional coherence on spherical boundaries of causal diamonds. Causal constraints reduce the number of independent degrees of freedom, impose new angular symmetries, and eliminate cosmic variance for purely angular 2-point correlations. Distortions of causal structure from vacuum fluctuations are modeled as gravitational memory from randomly oriented outgoing and incoming gravitational null shocks, with nonlocally coherent directional displacements on curved surfaces of causal diamonds formed by standard inflationary horizons. The angular distribution is determined by axially symmetric shock displacements on circular intersections of the comoving sphere that represents the CMB photosphere with other inflationary horizons—those centered on it, and those that pass through an observer’s world line. Displacements on thin spheres at the end of inflation have a unique angular power spectrum

C
ℓ

that approximates the standard expectation on small angular scales, but differs substantially at large angular scales due to horizon curvature. For a thin sphere, the model predicts a universal angular correlation function

C
(
Θ
)

with an exact ‘causal shadow’ symmetry,

C
(
π

/

4
<
Θ
<
3
π

/

4
)
=
0

, and significant large-angle parity violation. We apply a rank statistic to compare models with WMAP and Planck satellite data, and find that a causally-coherent model with no shape parameters or cosmic variance agrees with the measured

C
(
Θ
)

better than a large fraction (

>

0.9999

) of standard model realizations. Model-independent tests of holographic causal symmetries are proposed.
A new medium-long term polar motion prediction method based on sliding average within difference series
Authors: Wang Leyang , Miao Wei , Wu Fei
Published: July 2023

In response to the problem that the input data and combination method of existing polar motion (PM) prediction methods are relatively single, which leads to the limited satisfaction of PM prediction accuracy by major satellite navigation orbiting systems and deep space exploration projects. This study borrows the idea of differential method and proposes to push back the forecast after selecting several samples within the PM Y, X and Y–X series by sliding average. In the constructed new series, the high-frequency terms are effectively attenuated. Then, the pushing back forecasts are combined in pairs with those of the traditional method. After least-squares extrapolation and autoregressive (LS + AR) modeling, the optimal combination was found. Among them, the prediction of PMX is obtained by subtracting the forecast of PMY of traditional method and the prediction of PM(Y–X) of the sliding average method, the forecast of PMY is obtained by adding the forecast of PMX of the sliding average method and the forecast of PM(Y–X) of the traditional method. The results of the 418-week hindcast experiment from 2012 to 2021 show that the proposed method has a greater improvement than the traditional method, and the corresponding 1–365-day mean absolute error (MAE) are improved by 31.46% and 21.11%, respectively, on average. It has certain advantages over the IERS Bulletin-A in the medium-long term, and the 150-day lead time predictions, the MAE of PMX and PMY were 14.678 and 17.232 mas, respectively, which were less than the 17.833 and 20.769 mas predicted by IERS Bulletin A. This not only verifies that the stability and ability of the proposed method have some competitive ability, but also provides new ideas for other time-series forecasting studies.
Modal frequencies evaluation of a damaged bridge using RCVMD algorithm based on sensor dynamic responses
Authors: Xiong Chunbao , Wang Meng , Shang Zhi , Liu Tao , Shi Qingfa
Published: July 2023

This paper aims to employ high-rate global navigation satellite system real-time kinematic (GNSS-RTK) and triaxial accelerometer sensors to evaluate the modal frequencies of a damaged long-span bridge based on the proposed modified variational mode decomposition algorithm. Firstly, in the modified VMD, the relative root mean square error was presented to optimize the decomposition parameter K, the correlation criterion was introduced to select the suitable intrinsic mode function components. The above procedure is called the RCVMD algorithm. Subsequently, the performance comparison evaluation experiments proved that the RCVMD algorithm was more advantageous in the decomposition and reconstruction of signals, had a better noise reduction effect in the signal with different noise levels, and was suitable to process the actual measurement response. Finally, in the field experiment, the modal frequencies of the damaged bridge were correctly detected from the GNSS-RTK displacement and acceleration responses according to the RCVMD algorithm, and the accelerometer picked up the high-order structural frequencies, demonstrating the reliability of the proposed method. The frequency characteristics of the damaged bridge are different from the normal state. The first and third-order frequencies increase, which is especially obvious in the first-order frequency, yet the second-order frequency decreases. The measured results have practical applications and can provide data support for the maintenance of the damaged bridge.
GaN-based cryogenic temperature power electronics for superconducting motors in cryo-electric aircraft
Authors: Wadsworth Aaron , Thrimawithana Duleepa J , Zhao Lei , Neuburger Martin , Oliver Rachel A , Wallis David J
Published: July 2023

Climate change has spurred a shift to electric transportation, but aviation faces challenges with electric energy storage and propulsion. Cryogenically cooled superconducting motors, along with cryogenically cooled power electronics, offer a solution to increase the efficiency and power density of electric aircraft. This paper evaluates the feasibility of cryogenic power electronics by characterising new technologies (GaN, nanocrystalline) using new experimental techniques. It is found that the on resistance reductions of GaN E-high electron mobility transistors at cryogenic temperatures depend on the maximum blocking voltage of the device, and the size of the gate resistor for ohmic p-GaN devices. Different types of nanocrystalline cores are shown to vary greatly in their behaviour at cryogenic temperatures, which is measured using a modified core loss measurement circuit. Further analysis shows that the losses of a GaN based cryogenic inverter could potentially halve that of an equivalent Si based inverter.
The rank of contextuality
Authors: Horodecki Karol , Zhou Jingfang , Stankiewicz Maciej , Salazar Roberto , Horodecki Paweł , Raussendorf Robert , Horodecki Ryszard , Ramanathan Ravishankar , Tyhurst Emily
Published: July 2023

Quantum contextuality is one of the most recognized resources in quantum communication and computing scenarios. We provide a new quantifier of this resource, the rank of contextuality (RC). We define RC as the minimum number of non-contextual behaviors that are needed to simulate a contextual behavior. We show that the logarithm of RC is a natural contextuality measure satisfying several properties considered in the spirit of the resource-theoretic approach. The properties include faithfulness, monotonicity, and additivity under tensor product. We also give examples of how to construct contextual behaviors with an arbitrary value of RC exhibiting a natural connection between this quantifier and the arboricity of an underlying hypergraph. We also discuss exemplary areas of research in which the new measure appears as a natural quantifier.
Electronic phase transition, perpendicular magnetic anisotropy and high Curie temperature in Janus FeClF
Authors: Zhang Long , Liu Yuqi , Xu Zhiyuan , Gao Guoying
Published: July 2023

How to enhance the spin polarization, the Curie temperature and the perpendicular magnetic anisotropy (PMA) is crucial for the applications of 2D magnets in spintronic devices. In this work, based on the experimental FeCl2 flakes and the predicted in-plane magnetic anisotropy (IMA) and lower Curie temperature of FeCl2 monolayer, we use first-principles and Monte Carlo simulation to explore the strain and carrier-doping effects on the electronic and magnetic properties of Janus FeClF monolayer. The structure is stable within −10% to 2% biaxial strain. Janus FeClF monolayer can experience transitions from a half-semiconductor to a spin gapless semiconductor (SGS) around the −6% compressive strain, and from the IMA to the PMA at the −7% compressive strain. The super-exchange Fe–F/Cl–Fe interaction induces the ferromagnetic coupling, and the Curie temperature can be considerably enhanced from 56 K to 281 K at the −10% compressive strain. The half-metallicity can be achieved whether under electron doping or hole doping. The Fe-d orbitals and the spin–orbit coupling interaction between occupied and unoccupied intraorbital states are responsible for the electronic phase transition and the magnetic anisotropy, respectively. Remarkably, the compressive −10% strain and the 0.02 e doping collectively increase the Curie temperature to near room temperature (286 K). The high spin polarization (exhibiting SGS and half-metal), the PMA and the near-room-temperature ferromagnetism induced by strain and doping make Janus FeClF a promising candidate for 2D spintronic applications, which will stimulate experimental and theoretical broad studies on this class of Janus monolayers FeXY (X,Y = F, Cl, Br, and X ≠ Y).
Chiral single photons from deterministic quantum emitter arrays via proximity coupling to van der Waals ferromagnets
Authors: Liu Na , Xiao Licheng , Fu Shichen , Ma Yichen , Liu Song , Chen Siwei , Hone James , Yang Eui-Hyeok , Strauf Stefan
Published: July 2023

Chiral single photons are highly sought to enhance encoding capacities or enable propagation-dependent routing in nonreciprocal devices. Unfortunately, most semiconductor quantum emitters (QEs) produce only linear polarized photons unless external magnets are applied. Magnetic proximity coupling utilizing 2D ferromagnets promises to make bulky external fields obsolete. Here we directly grow Fe-doped MoS2 (Fe:MoS2) via chemical vapor deposition that displays pronounced hard ferromagnetic properties even in monolayer form. This approach with monolayer ferromagnets enables full utilization of the strain from the pillar stressor to form QE in WSe2 deterministically. The Fe:MoS2/WSe2 heterostructures display strong hysteretic magneto-response and high-purity chiral single photons with a circular polarization degree of 92 ± 1% (74% average) without external magnetic fields. Furthermore, the chiral single photons are robust against uncontrolled twist-angle and external stray-fields. This ability to manipulate quantum states and transform linear polarized photons into high-purity chiral photons on-chip enables nonreciprocal device integration in quantum photonics.
Spatial and temporal distribution of HCHO and its pollution sources based on satellite remote sensing: a case study of the Yangtze River Economic Belt
Authors: Huang Cheng , Ju Tianzhen , Geng Tunyang , Fan Jiachen , Peng Shuai , Xia Xuhui , Niu Xiaowen
Published: July 2023

In recent years, with the acceleration of industrialization and the expansion of urban scale, air pollution including formaldehyde (HCHO) becomes more and more serious. In order to study HCHO pollution in the Yangtze River Economic Belt (YEB), the temporal and spatial evolution of atmospheric HCHO and its influencing factors were analyzed by using the Ozone Monitoring Instrument (OMI) during 2012–2021. The results showed that the concentration of YEB HCHO column was unevenly distributed, with high values concentrated in Anhui, Jiangsu, Yunnan and Hubei provinces. During the past 10 years, the concentration of YEB HCHO column varied between 10.28 and 17.19 × 1015 molec cm−2, and the lowest concentration of HCHO column was 13.16 × 1015 molec cm−2 in 2015. However, it reached the peak value in 2018 (14.93 × 1015 molec cm−2). In natural sources, normalized vegetation index (NDVI) and leaf area index (LAI) had greater influence on YEB HCHO, and the correlation was −0.91 ∼ 0.97 and −0.9 ∼ 0.95, respectively. The positive correlation area between HCHO and Mean annual temperature (MAT) reached 93%. The contribution of high-intensity human activity areas to HCHO cannot be underestimated. Industrial and civil sources have great influence on HCHO. In addition, the potential source of HCHO in Shanghai is affected by local emission sources, trans-regional potential sources, northwest air mass and ocean airflow.
Reformulation of traditional Iranian food (Doeeneh) using probiotics: Bifidobacterium animalis subsp. lactis BB-12, Lactobacillus acidophilus LA-5, Lacticaseibacillus rhamnosus LGG, and inulin and its effect on diabetic and non-diabetic rats
Authors: AziziShafa Mahdi , Akhondzadeh Basti Afshin , Sharifan Anousheh , Khanjari Ali
Published: July 2023

Objectives

The purposes of this study were to produce novel formulations of Doeeneh using three probiotic strains and different inulin ratios and to investigate the survival of probiotics. Likewise, the effect of Doeeneh on the biological properties of non-diabetic and diabetic rats was also evaluated.

Materials and Methods

Doeeneh, composed of milk and wheat bulgur, was enriched with different proportions of inulin and fermented by Bifidobacterium animalis subsp. lactis BB-12 (B), Lactobacillus acidophilus LA-5 (A), Lacticaseibacillus rhamnosus LGG (R), and their co-cultures. The physicochemical and sensory properties and probiotics viability were investigated for 14 d. Diabetes was induced in albino rats by administration of alloxan monohydrate (150 mg/kg i.p.). Changes in weight and blood glucose were measured weekly, and food and water consumption were measured daily; total cholesterol and triglycerides were measured after 35 d by a biochemical kit.

Results

The increased proportion of high-degree of polymerization inulin decreased pH and increased acidity. However, a higher concentration of inulin applied to Doeeneh resulted in a slower decrease in pH value. This result can show the buffering effect of inulin in Doeeneh as well; changes in pH were slow over time due to the presence of the buffering compounds. Therefore, the probiotics’ survival was in the standard range even in the inulin-free sample. Likewise, the Doeeneh sample containing 5% inulin (SABR3) considerably reduced the levels of blood glucose, total cholesterol, and triglyceride in diabetic rats. Moreover, the diabetic rats fed Doeeneh demonstrated less weight loss and food/water intake than the control.

Conclusions

Traditional foods and their preparation methods are a suitable target for the development of health-oriented products, and functional food with nutraceutical capabilities can be designed and produced based on them.
Characterization of a novel polyextremotolerant fungus, Exophiala viscosa, with insights into its melanin regulation and ecological niche
Authors: Carr Erin C , Barton Quin , Grambo Sarah , Sullivan Mitchell , Renfro Cecile M , Kuo Alan , Pangilinan Jasmyn , Lipzen Anna , Keymanesh Keykhosrow , Savage Emily , Barry Kerrie , Grigoriev Igor V , Riekhof Wayne R , Harris Steven D
Published: July 2023

Black yeasts are polyextremotolerant fungi that contain high amounts of melanin in their cell wall and maintain a primar yeast form. These fungi grow in xeric, nutrient depletes environments which implies that they require highly flexible metabolisms and have been suggested to contain the ability to form lichen-like mutualisms with nearby algae and bacteria. However, the exact ecological niche and interactions between these fungi and their surrounding community are not well understood. We have isolated 2 novel black yeasts from the genus Exophiala that were recovered from dryland biological soil crusts. Despite notable differences in colony and cellular morphology, both fungi appear to be members of the same species, which has been named Exophiala viscosa (i.e. E. viscosa JF 03-3 Goopy and E. viscosa JF 03-4F Slimy). A combination of whole genome sequencing, phenotypic experiments, and melanin regulation experiments have been performed on these isolates to fully characterize these fungi and help decipher their fundamental niche within the biological soil crust consortium. Our results reveal that E. viscosa is capable of utilizing a wide variety of carbon and nitrogen sources potentially derived from symbiotic microbes, can withstand many forms of abiotic stresses, and excretes melanin which can potentially provide ultraviolet resistance to the biological soil crust community. Besides the identification of a novel species within the genus Exophiala, our study also provides new insight into the regulation of melanin production in polyextremotolerant fungi.
Existence of Solutions on the Critical Hyperbola for a Pure Lane–Emden System with Neumann Boundary Conditions
Authors: Pistoia Angela , Schiera Delia , Tavares Hugo
Published: July 2023

We study the following Lane–Emden system: $$\begin{align*} & -\Delta u=|v|^{q-1}v \quad \ \textrm{in}\ \Omega, \qquad -\Delta v=|u|^{p-1}u \quad \ \textrm{in}\ \Omega, \qquad u_{\nu}=v_{\nu}=0 \quad \ \textrm{on}\ \partial \Omega, \end{align*}$$with $\Omega $ a bounded regular domain of ${\mathbb{R}}^{N}$, $N \ge 4$, and exponents $p, q$ belonging to the so-called critical hyperbola $1/(p+1)+1/(q+1)=(N-2)/N$. We show that, under suitable conditions on $p, q$, least-energy (sign-changing) solutions exist, and they are classical. In the proof we exploit a dual variational formulation, which allows to deal with the strong indefinite character of the problem. We establish a compactness condition which is based on a new Cherrier-type inequality. We then prove such condition by using as test functions the solutions to the system in the whole space and performing delicate asymptotic estimates. If $N \ge 5$, $p=1$, the system above reduces to a biharmonic equation, for which we also prove existence of least-energy solutions. Finally, we prove some partial symmetry and symmetry-breaking results in the case $\Omega $ is a ball or an annulus.
Prevotella and Gardnerella Are Associated With Treatment Failure Following First-line Antibiotics for Bacterial Vaginosis
Authors: Plummer Erica L , Sfameni Amelia M , Vodstrcil Lenka A , Danielewski Jennifer A , Murray Gerald L , Fehler Glenda , Fairley Christopher K , Garland Suzanne M , Chow Eric P F , Hocking Jane S , Bradshaw Catriona S
Published: July 2023

Background

Bacterial vaginosis (BV) is a common vaginal dysbiosis that often recurs following first-line antibiotics. We investigated if vaginal microbiota composition was associated with BV recurrence.

Methods

We analyzed samples and data from 121 women who participated in 3 published trials evaluating novel interventions for improving BV cure, including concurrent antibiotic treatment of regular sexual partners (RSPs). Women diagnosed with BV received first-line antibiotics and self-collected vaginal swabs pretreatment and the day after finishing antibiotics (immediately posttreatment). 16S rRNA gene sequencing was performed on vaginal samples. Logistic regression explored associations between BV recurrence and features of the vaginal microbiota pre- and posttreatment.

Results

Sixteen women (13% [95% confidence interval {CI}, 8%–21%]) experienced BV recurrence within 1 month of treatment. Women with an untreated RSP were more likely to experience recurrence than women with no RSP (P = .008) or an RSP who received treatment (P = .011). A higher abundance of Prevotella pretreatment (adjusted odds ratio [AOR], 1.35 [95% CI, 1.05–1.91]) and Gardnerella immediately posttreatment (AOR, 1.23 [95% CI, 1.03–1.49]) were associated with increased odds of BV recurrence.

Conclusions

Having specific Prevotella spp prior to recommended treatment and persistence of Gardnerella immediately posttreatment may contribute to the high rates of BV recurrence. Interventions that target these taxa are likely required to achieve sustained BV cure.
Enhancing performance of electron holography with mathematical and machine learning–based denoising techniques
Authors: Anada Satoshi , Nomura Yuki , Yamamoto Kazuo
Published: July 2023

Electron holography is a useful tool for analyzing functional properties, such as electromagnetic fields and strains of materials and devices. The performance of electron holography is limited by the ‘shot noise’ inherent in electron micrographs (holograms), which are composed of a finite number of electrons. A promising approach for addressing this issue is to use mathematical and machine learning–based image-processing techniques for hologram denoising. With the advancement of information science, denoising methods have become capable of extracting signals that are completely buried in noise, and they are being applied to electron microscopy, including electron holography. However, these advanced denoising methods are complex and have many parameters to be tuned; therefore, it is necessary to understand their principles in depth and use them carefully. Herein, we present an overview of the principles and usage of sparse coding, the wavelet hidden Markov model and tensor decomposition, which have been applied to electron holography. We also present evaluation results for the denoising performance of these methods obtained through their application to simulated and experimentally recorded holograms. Our analysis, review and comparison of the methods clarify the impact of denoising on electron holography research.
Single-cell multi-gene identification of somatic mutations and gene rearrangements in cancer
Authors: Grimes Susan M , Kim Heon Seok , Roy Sharmili , Sathe Anuja , Ayala Carlos I , Bai Xiangqi , Almeda-Notestine Alison F , Haebe Sarah , Shree Tanaya , Levy Ronald , Lau Billy T , Ji Hanlee P
Published: July 2023

In this proof-of-concept study, we developed a single-cell method that provides genotypes of somatic alterations found in coding regions of messenger RNAs and integrates these transcript-based variants with their matching cell transcriptomes. We used nanopore adaptive sampling on single-cell complementary DNA libraries to validate coding variants in target gene transcripts, and short-read sequencing to characterize cell types harboring the mutations. CRISPR edits for 16 targets were identified using a cancer cell line, and known variants in the cell line were validated using a 352-gene panel. Variants in primary cancer samples were validated using target gene panels ranging from 161 to 529 genes. A gene rearrangement was also identified in one patient, with the rearrangement occurring in two distinct tumor sites.
Model Complexity, Expectations, and Asset Prices
Authors: Molavi Pooya , Tahbaz-Salehi Alireza , Vedolin Andrea
Published: July 2023

This paper analyses how limits to the complexity of statistical models used by market participants can shape asset prices. We consider an economy in which the stochastic process that governs the evolution of economic variables may not have a simple representation, and yet, agents are only capable of entertaining statistical models with a certain level of complexity. As a result, they may end up with a lower-dimensional approximation that does not fully capture the intertemporal complexity of the true data-generating process. We first characterize the implications of the resulting departure from rational expectations and relate the extent of return and forecast-error predictability at various horizons to the complexity of agents’ models and the statistical properties of the underlying process. We then apply our framework to study violations of uncovered interest rate parity in foreign exchange markets. We find that constraints on the complexity of agents’ models can generate return predictability patterns that are simultaneously consistent with the well-known forward discount and predictability reversal puzzles.
Integrating Disaster Management Into Curricula: A Successful Collaboration With Community Partners
Authors: Gibson Terri L. , Davis Kathy , Smith Ann L.
Published: July 2023

Millions of people are killed annually in disasters, and even more are injured, displaced, and in need of emergency assistance. Communities continue to need nurses who can respond effectively during times of disaster. A one-credit course was developed to provide a collaborative and engaging approach to prepare students for disaster and mass casualty situations. Student evaluation responses regarding all segments of the course indicate satisfaction and quality learning. The course prepared and qualified students to volunteer for a community service organization and provide community-based care.
Effective Postoperative Surveillance Protocol after Thoracoscopic Esophagectomy Focusing on Symptoms in Patients with Esophageal Cancer
Authors: Tajima Kohei , Koyanagi Kazuo , Ozawa Soji , Kazuno Akihito , Yamamoto Miho , Shoji Yoshiaki , Yatabe Kentaro , Kanamori Kohei , Zhao Hongbo , Mori Masaki
Published: July 2023

BACKGROUND:

The optimal postoperative surveillance protocol after esophagectomy for patients with esophageal cancer has still not been established. We investigated the risk factors for recurrence of esophageal cancer to devise an appropriate surveillance protocol. We focused on the appearance and worsening of symptoms to determine if additional imaging examinations should be performed.

STUDY DESIGN:

We enrolled 416 patients with esophageal and esophagogastric junctional cancer who had undergone thoracoscopic esophagectomy at Tokai University Hospital. Outpatient visits for the patients are usually scheduled at least 4 times per year with CT imaging and blood biochemical examination. We evaluated the time to recurrence after esophagectomy, especially the correlation of this parameter with the appearance and worsening of symptoms during the postoperative outpatient follow-up.

RESULTS:

Of the 416 patients, recurrence occurred in 127 patients (30.5%). The median time to recurrence was 6 months after esophagectomy; recurrence occurred within 24 months in 112 patients (88%), and 51 of these patients (40%) developed some new symptom(s) (symptomatic group) before the diagnosis of recurrence. The number of patients who developed recurrence within 6 months was significantly higher in the symptomatic group compared with that in the asymptomatic group (66.7% vs 46.0%, p = 0.02). The overall survival in the symptomatic group was significantly shorter than that in the asymptomatic group (p < 0.001).

CONCLUSIONS:

We advocate an effective surveillance protocol depending on the appearance and worsening of symptoms to diagnose recurrence of esophageal cancer; we recommend routine imaging examinations every 6 months and clinical outpatient follow-up at even shorter intervals for the first 24 months after esophagectomy.
The evolution of nest site use and nest architecture in modern birds and their ancestors
Authors: Mainwaring Mark C. , Medina Iliana , Tobalske Bret W. , Hartley Ian R. , Varricchio David J. , Hauber Mark E.
Published: July 2023

The evolution of nest site use and nest architecture in the non-avian ancestors of birds remains poorly understood because nest structures do not preserve well as fossils. Nevertheless, the evidence suggests that the earliest dinosaurs probably buried eggs below ground and covered them with soil so that heat from the substrate fuelled embryo development, while some later dinosaurs laid partially exposed clutches where adults incubated them and protected them from predators and parasites. The nests of euornithine birds—the precursors to modern birds—were probably partially open and the neornithine birds—or modern birds—were probably the first to build fully exposed nests. The shift towards smaller, open cup nests has been accompanied by shifts in reproductive traits, with female birds having one functioning ovary in contrast to the two ovaries of crocodilians and many non-avian dinosaurs. The evolutionary trend among extant birds and their ancestors has been toward the evolution of greater cognitive abilities to construct in a wider diversity of sites and providing more care for significantly fewer, increasingly altricial, offspring. The highly derived passerines reflect this pattern with many species building small, architecturally complex nests in open sites and investing significant care into altricial young.

This article is part of the theme issue ‘The evolutionary ecology of nests: a cross-taxon approach’.