bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance of magnetic shape anisotropy in determining triaxial magnetic anisotropy of ferromagnetic semiconductor CrSCl monolayer
Authors: Tu Yufei , Zhang Jiawen , Tian Zhuang Zhuang , Du Hailong , Zhao Long , Jia Minglei , Wang Bing
Published: October 2024

Magnetic anisotropy (MA) is pivotal for stabilizing long-range magnetic order in two-dimensional (2D) systems against thermal fluctuations. Here, we conduct a comprehensive investigation of the electronic and magnetic properties of CrSCl monolayer using first-principles methods and Monte Carlo (MC) simulations. Our results reveal that CrSCl monolayer exhibit a direct band gap ferromagnetic semiconductor (FMS) with a high Curie temperature (TC, 143 K). Notably, we identify triaxial magnetic anisotropy in this monolayer, characterized by the easy magnetization axis along the y-axis, intermediate axis along the x-axis, and hard axis along the z-axis. This anisotropy arises from a combination of magnetocrystalline anisotropy and shape anisotropy, in which shape anisotropy dominating over weak magnetocrystalline anisotropy. Orbital projection analysis shows that the major contribution of magnetic anisotropy energy comes from the d orbital of Cr atom. These findings provide some insights into the strain response of MA and suggest that studies of other FM monolayers may uncover future contenders for strain-switchable and ultra-compact spintronics devices.
A highly sensitive and selective ZnO-based ammonia sensor: Fe- doping effect
Authors: Chaudhary Dinesh Kumar , Joshi Surya Kumari , Shrestha Rajesh
Published: October 2024

This study investigates the gas sensing capabilities of ZnO and Fe-doped ZnO films prepared via a cost-effective spin coating method. The films were characterized optically, structurally, and morphologically. X-ray diffraction revealed good crystal quality with a polycrystalline nature, and wurzite structure, though crystal quality and crystallite size decreased with Fe doping. Optical measurements indicated an increased optical band gap from 3.205 ± 0.002 to 3.220 ± 0.002 eV after Fe doping. Scanning electron microscope images confirmed spherical grainy structures with reduced grain sizes after Fe doping. Gas sensing measurements at room temperature (RT) at an exposure of vapors of various toxic chemicals (acetone, ethanol, propanol, methanol, and ammonia), demonstrated a highly selective nature of ZnO and Fe-ZnO towards the ammonia. The Fe-doping into ZnO improved the ammonia sensing capability of ZnO film. The Fe-ZnO film exhibited a gas response of 388.8 ± 5.5 at 400 ppm ammonia exposure, which was nearly 10 times larger than that of ZnO film with a response/recovery time of 22/51 s, good stability, and good repeatability. The Fe-ZnO film’s higher response is attributed to its smaller grain sizes and surplus of charge carriers after Fe doping which promote the adsorption of extra oxygen ions onto the film’s surface and the subsequent interaction between the adsorbed oxygen ions ammonia molecules. It could detect up to the lower limit of 1 ppm ammonia with a response of 24.2 ± 0.9, which is better than the previous reports. These results reveal the Fe-ZnO film as a viable material for developing a cost-effective and efficient ammonia sensor at room temperature.
Investigating the photocatalytic efficacy of a porous cuprous gallate (CuGa2O4) thick film
Authors: Huseynzade Fatima , Akbaba Yesim , Shawuti Shalima , Can Musa Mutlu
Published: October 2024

The study aimed to investigate the photocatalytic activity of porous copper gallate (CuGa2O4) thick film with significant wall dimensions. The thick film was meticulously fabricated using tape casting systems, with CuGa2O4 nanoparticles synthesized by Sol–Gel technique and subsequently transformed into gels for the tape casting process. Rietveld refinements were employed to elucidate the crystal structure and lattice parameters of the CuGa2O4 spinel oxide lattice. Moreover, electronic energy configurations and optical transmittance measurements were acquired through UV-visible spectrophotometry. The correlations between the crystal structure, band gap change and formation of electronic energy levels in relation to the photocatalytic performance of CuGa2O4 were explored. The comprehensive examination provides valuable insights into the complex interaction between material properties and photocatalytic behavior, offering a nuanced understanding of the potential applications of porous CuGa2O4 thick films in various technological fields.
Positron interactions with vinyl acetate from 0.1 eV to 5 keV
Authors: Kaur Savinder , Arora Ajay Kumar , Bharadvaja Anand , Baluja Kasturi Lal
Published: October 2024

Scattering cross sections from positron impact on vinyl acetate are explored in the energy region 0.1 eV to a 5 keV, employing a cc-pVTZ basis set. The optimized molecular wavefunction of the target was obtained through a multi-center expansion of Gaussian-type orbitals in the Hartree–Fock self-consistent field framework. The elastic cross sections are computed using the single-centre-expansion formalism. Two distinct models were employed to address the long-range effects associated with the target's polar nature and yielded almost identical corrections. The Born-corrected elastic cross sections align more strongly with the existing experimental corrected data than the results reported from the independent-atom-model approximation. The differential and momentum transfer cross sections after applying Born-correction are also reported. The direct ionization cross sections are obtained using the binary-encounter-Bethe model for positrons. The cross sections obtained by summing elastic and ionization cross sections align closely with ‘forward angle corrected’ experimental total cross sections across a significant energy range. The agreement significantly improves beyond 30 eV, suggesting that the omission of excitation and positronium formation cross sections becomes less significant. A brief analysis of the electron interaction with the target is also made.
The electronic structure, optical, and transport properties of novel SrScCu3M4 (M = Se, Te) semiconductors
Authors: Khan Muhammad Salman , Gul Banat , Mohamed Abdelhay Salah , Abbas Faheem
Published: October 2024

The density functional theory is used to investigate the complex relationships between the physical properties of the novel quaternary SrScCu3M4 (M = Se, Te) semiconductors. The computed negative formation energy values of these materials demonstrate their stable nature. The distribution of ELF around chalcogens and Cu atoms shows substantial localization, indicating strong covalent bonding. The phonon dispersion curves show that the materials have good structural stability with no negative frequencies. The s/p states of Se and s/p/d of Te play minor roles, while Cu-d states have a considerable influence on the valence band region. The computed energy gap values without SOC for SrScCu3Se4 and SrScCu3Te4 are 1.29, and 0.90, respectively. The predicted energy gap values with SOC for SrScCu3Se4 and SrScCu3Te4 are 1.35, and 0.87, respectively. SrScCu3Se4 is a harder and more compressible material than SrScCu3Te4, as confirmed by its higher bulk modulus. The ε
1(ω) values decrease and ultimately become negative, which suggests these materials are reflective. SrScCu3Te4 exhibits plasmon resonance at a high energy domain as compared to SrScCu3Se4, resulting in a greater loss function. The current study can establish the potential efficiency of these materials in cutting-edge optoelectronic devices.
New scheme of cooperative compressed spectrum sensing
Authors: Benzater Hadj Abdelkader , Lassami Nacerredine , Teguig Djamal
Published: October 2024

This study addresses key challenges in sparse signal recovery and compressed spectrum sensing (CSS), focusing on low signal-to-noise ratios (SNR), and the computational complexity of cooperative systems. Motivated by the need for faster and more accurate recovery techniques, we first investigate and generalize the Reduced-Set Matching Pursuit (RMP) algorithm, which overcomes the speed and accuracy limitations of conventional greedy algorithms. Secondly, we propose a novel spatial averaging technique that enhances detection performance by exploiting data from multiple users to counteract low SNR. Lastly, we integrate cooperation into CSS, further improving the detection capabilities during the recovery process. Compared to existing techniques like Joint Sparse Recovery (JSR) and CoSaMP, which face computational and accuracy constraints in real-time applications, the RMP algorithm, combined with the Virtual method (data transformation) and AND fusion rule, delivers superior performance than JSR methods. Moreover, spatial averaging significantly increases the probability of cooperative detection Q

d
, with SNR increasing linearly by a factor of L − 1 per channel. The results are validated through the implementation of SDR. These findings demonstrate the potential of RMP and cooperation to overcome current limitations in CSS, advancing the state-of-the-art in spectrum sensing for collaborative networks.
Zinc cobalt sulfide with carbon (graphene oxide and CNT) based nanocomposite as positive electrode for asymmetric coin cell supercapacitors
Authors: Ravisankar D , Geetha D , Ramesh P S
Published: October 2024

The world dependence on portable electronic devices has increased the demand for high-performance energy storage devices. The use of transition metal sulfides as faradaic electrode materials for electrochemical energy storage is rapidly increasing due to their high energy density. Herein Zinc Cobalt Sulfide (ZCS) with graphene oxide (GO) and carbon nanotubes (CNT) were used to create an interconnected ZCS composite network using a solvothermal technique. The materials were characterized by utilizing XRD, FT-Raman, TGA, FESEM/EDX, XPS, and BET. The electrochemical performance of the materials was examined using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The prepared electrodes exhibited both pseudocapacitor behavior and double-layer capacitor behavior, indicating the hybrid nature. Furthermore, All the electrode ZCS, ZCS/GO, ZCS/CNT, and ZCS/GO/CNT electrodes demonstrated higher capacitance behavior, with values of 420, 551, 585 and 811 F g−1 at 1 A/g. Among these ZCS/GO/CNT electrode exhibits outstanding electrochemical properties, with a notable retention of 81.08% at 10 Ag−1 because Combining ZCS nanoparticles with interconnected GO and CNT provides excellent electronic conductivity and stability. The assembled ZCS/GO/CNT//graphene oxide asymmetric coin cell (ACC) supercapacitor showed a high energy density of 33.3 Wh kg–1 at a power density of 624 W kg–1. The 3D nanostructure of ZCS/GO/CNT/Graphene oxide has great potential for developing foldable energy storage devices.
Using linear and nonlinear entanglement witnesses to generate and detect bound entangled states on an IBM quantum processor
Authors: Gulati Vaishali , Singh Gayatri , Dorai Kavita
Published: October 2024

We investigate bound entanglement in three-qubit mixed states which are diagonal in the Greenberger-Horne-Zeilinger (GHZ) basis. Entanglement in these states is detected using entanglement witnesses and the analysis focuses on states exhibiting positive partial transpose (PPT). We then compare the detection capabilities of optimal linear and nonlinear entanglement witnesses. In theory, both linear and nonlinear witnesses produce non-negative values for separable states and negative values for some entangled GHZ diagonal states with PPT, indicating the presence of entanglement. Our experimental results reveal that in cases where linear entanglement witnesses fail to detect entanglement, nonlinear witnesses are consistently able to identify its presence. Optimal linear and nonlinear witnesses were generated on an IBM quantum computer and their performance was evaluated using two bound entangled states (Kay and Kye states) from the literature, and randomly generated entangled states in the GHZ diagonal form. Additionally, we propose a general quantum circuit for generating a three-qubit GHZ diagonal mixed state using a six-qubit pure state on the IBM quantum processor. We experimentally implemented the circuit to obtain expectation values for three-qubit mixed states and compute the corresponding entanglement witnesses.
Minimally deformed regular Hayward black hole solutions in Rastall theory
Authors: Sharif M , Sallah Malick
Published: October 2024

We profit from the gravitational decoupling algorithm via the minimal deformation scheme and extend the regular Hayward black hole, thereby obtaining novel black hole models in the context of Rastall theory. The field equations sourced by multiple matter are decoupled into two systems. The initial set is determined by the metric potentials of the Hayward black hole while the second set which describes additional source is solved using a constraint given by an equation of state. The solutions of the subfield equations allow us to obtain two new solutions by combining them in a linear manner. For given values of the Rastall and decoupling parameters, their some thermodynamic characteristics are studied for the resulting models. It turns out that only the first model preserves asymptotic flatness. It is found that the first and second models are described by exotic and ordinary matter, respectively. Finally, we obtain an acceptable behavior of the Hawking temperature and thermodynamic stability for both models.
Gravitational waves for eccentric extreme mass ratio inspirals of self-dual spacetime
Authors: Liu Yunlong , Zhang Xiangdong
Published: October 2024

In this paper, we calculate the frequencies of geodesic orbits in self-dual spacetime on the equatorial plane and obtain the leading-order effects of loop quantum parameters P on the energy flux and angular momentum flux in eccentric extreme mass ratio inspirals. The gravitational waveform under different eccentricity is carried out by improved “analytic-kludge” method. We calculate the waveform mismatches for the LISA detector and the measurement error on loop quantum parameters. The constraint capability on P will be improved by a factor of 3 to 10, compared to the weak field experiments in the solar system.
Impact of lensing bias on the cosmological dispersion measure
Authors: Takahashi Ryuichi
Published: October 2024

The cosmological dispersion measure (DM) as a function of redshift, derived from localized fast radio bursts (FRBs), has been used as a tool for constraining the cosmic ionized fraction and cosmological parameters.
For these purposes, the DM in a homogeneous cosmological model has typically been used, neglecting the inhomogeneity of matter distribution.
In this study, we derive a bias in the ensemble average of the DM over many FRBs owing to gravitational lensing by the inhomogeneous matter distribution based on cosmological perturbation theory.
We demonstrate that the ensemble average is 0.4 %–1 % smaller than the DM in the corresponding homogeneous model for a source redshift of z
s=1, according to recent cosmological hydrodynamic simulations of IllustrisTNG and BAHAMAS.
This reduction occurs because light rays from FRBs tend to avoid high-density regions owing to lensing deflection.
We also discuss another selection effect, magnification bias, where demagnified FRBs with low DMs, fainter than the detection threshold, are excluded from the observed sample, leading to a selective observation of magnified FRBs with high DMs.
Lensing bias, including magnification bias, must be considered to achieve percent level accuracy in the DM-redshift relation.
Kármán vortex street in Bose–Einstein condensate with PT symmetric potential
Authors: Shao Kaihua , Xi Baolong , Xi Zhonghong , Tu Pu , Ma Jinping , Zhao Xi , Meng Hongjuan , Shi Yuren
Published: October 2024

Kármán vortex street not only exists in nature, but also widely appears in engineering practice, which is of great significance for understanding superfluid. Parity-time (PT) symmetric potential provides a good platform for the study of Kármán vortex streets. In this paper, different patterns of vortex shedding formed behind PT symmetric potential in Bose–Einstein condensate (BEC) are simulated numerically. Kármán vortex streets and others are discovered to emerge in the wake of a moving obstacle with appropriate parameters. Compared with BEC without PT symmetric potential, the frequency and amplitude of the drag force are more complex. The parametric regions of the combined modes are scattered around the Kármán vortex street. Numerical simulations indicate that the imaginary part of the PT symmetric potential affects the vortex structure patterns. Finally, we proposed an experimental protocol that may observe a Kármán vortex street.
Constraints on covariant Horava-Lifshitz gravity from precision measurement of planetary gravitomagnetic field
Authors: Zhang 张 Li-Dong 立冬 , Li 李 Li-Fang 丽仿 , Xu 徐 Peng 鹏 , Bian 边 Xing 星 , Luo 罗 Zi-Ren 子人
Published: October 2024

As a generalization of Einstein's theory, Horava-Lifshitz gravity has attracted significant interest owing to its healthy ultraviolet behavior. In this paper, we analyze the impact of the Horava-Lifshitz corrections on the gravitomagnetic field. We propose a new measurement method for the planetary gravitomagnetic field based on space-based laser interferometry, which is further used to constrain the Horava-Lifshitz parameters. Our analysis shows that high-precision laser gradiometers can indeed limit the parameters in Horava-Lifshitz gravity and improve the results by one or two orders of magnitude compared with the existing theories. Our novel method also provides insights into how to constrain the parameters in the modified gravitational theory to gain deeper understanding of this complex framework and pave the way for potential technological advancements in the field.
Research on differentiated lightning protection application of power lines based on laser point cloud data
Authors: Ma Zhiqing , Zhao Wenhua , Li Qiuyang , Yang Taohui , Qu Quanlei , Bao Zhenghong , Wang Shengjie , Hai Jingwen
Published: October 2024

The collection and processing of data in lightning protection assessment of transmission lines takes a long time and accuracy is difficult to ensure. Therefore, a laser point cloud data registration method based on pole and tower material coordinate transformation is proposed for differential lightning protection evaluation of transmission lines. Using DBSCAN algorithm, combined with point cloud data voxel filtering and noise reduction methods, to achieve data segmentation of transmission line tower body. Based on the characteristics of the symmetrical structure of the tower body, the coordinate transformation method is adopted to achieve the registration of multiple point cloud data. The parameters in the tower structure are obtained by concatenating and fusing elements such as the wire point cloud, lightning protection line point cloud, and tower point cloud. After verification by lightning protection assessment, the proposed method simplifies the processing flow of data compliance detection during the assessment process, reduces the time cost of lightning protection assessment, and greatly improves the accuracy and effectiveness of lightning risk assessment results.
PID controller design for manipulating electrorheological valves with mesh electrodes using in 2D matrix display
Authors: Zhan Ruochen , Guo Shaopeng , Xu Luning , Han Li
Published: October 2024

The electrorheological (ER) valve with parallel electrodes structure has an inherent characteristic. The electrodes gap is the same as its flow channel gap, which causes a strong coupling relationship between the applied voltages and the flow rates of the ER valve. If flow rates of ER valves in the condition of turn on operational mode were increased, their applied voltages were increased necessarily for keeping their shutdown operational mode, which brings a bunch of problems of product costs and dimensions, especially when multiple ER valves with different operational modes work together, such as application of ER valves matrix used in 2D matrix displays. The mesh electrodes structure can decouple the relationship between the electrodes gap and the flow channel gap of parallel electrodes structure. However, due to the complexity of mesh electrodes structure, a mathematic model is difficult to be established theoretically. And, a mathematic model of ER valve with mesh electrodes plays a vital role in designing its controller. By analyzing the composition elements of an ER valve with mesh electrodes, a semi experimental model was established using the parametric identification toolbox of MATLAB. The consistency between the output of recognition model and the output of validation data reaches 93.46%. Subsequently the PID controller for ER valves with mesh electrodes was designed to meet the operational demands of a 2D matrix display using Simulink. The constrain of simulation was that the pressures of flow channel inlets of ER valves, the dynamic responses of ER valves with mesh electrodes kept stable and within its operational range. The results will be helpful for applications of ER valves with mesh electrodes.
A portable test system for the radar
Authors: Huang Zhiqiang , Liu Shangguang , Zhong Yonglei , Gong Wei
Published: October 2024

In order to adapt to the increasingly fierce battlefield confrontation scenarios, a portable, fast deployment and folding test system for the radar is proposed. The corresponding key test items of radar such as spectrum, waveform, lobe, target tracking and data analysis can be completed on the test system. After the Built-in-Test (BIT) information and test system results are integrated, the corresponding evaluation report and implementation recommendations can be provided to the maintenance personnel. This paper expounds the design of each subsystem step by step. The Main Control Unit (MCU) is the task scheduling and information integration center for the system. The corresponding high frequency components, processing components, storage components have been implemented systematic and miniaturized design. In the end, the improvement direction and prospect of the test system are given.
A flat sealing test device using water as the medium
Authors: Guo Fengquan , Ma Chuanhai , Wang Jingyi
Published: October 2024

The planar sealing test device uses water as the working medium to determine the sealing of the test plane, Water has a sealing effect and an intuitive visual effect. Fix the test piece on the testing device platform, and the working medium water moves upward under the thrust of the piston rod to fully cover the test piece. Increase a certain amount of air pressure inside the test piece, check for bubbles around the test piece, and determine the sealing of the plane. This design compensates for the shortcomings of flat sealing inspection equipment, and more conveniently and efficiently solves the sealing inspection problem before the assembly of flat sealing components, reducing energy consumption, saving resources, and improving production efficiency.
Research on Textured Polishing Wheel (TPW) patterns for polishing dental ceramic materials in anhydrous environments
Authors: Hou Liyuan , Chen Chaoxu , Yang Wei
Published: October 2024

Dental ceramics commonly utilize high-hardness fused silica materials for the fabrication of inlays, crowns, and artificial dental implants, with their processing efficiency and surface roughness (Ra) directly influencing manufacturing costs and product quality. This study presents the development of a Textured Polishing Wheel (TPW) featuring three distinct surface patterns (spiral, linear, and radial), achieved through single-point diamond and pulsed laser processing techniques. It investigates the effects of these patterns on the removal rate and surface roughness (Ra) of dental ceramics during the polishing process. Results indicate that while TPW demonstrates comparable material removal depth to non-textured polishing wheels, it marginally increases surface roughness (Ra). Moreover, TPW significantly reduces burning and wear on the wheel surface during polishing. Pulsed laser ablation of TPW leads to further improvement in surface roughness, thereby enhancing the processing of dental ceramics. Experimental findings highlight the superior performance of spiral TPW, achieving a material removal rate of 4.2
μm/h
and a surface roughness (Ra) of approximately 2.2
nm
, thus meeting the manufacturing and functional requirements of dental ceramics.
Upgrade of the NaI(Tl) crystal encapsulation for the NEON experiment
Authors: Choi J.J. , Jeon E.J. , Kim J.Y. , Kim K.W. , Kim S.H. , Kim S.K. , Kim Y.D. , Ko Y.J. , Koh B.C. , Ha C. , Park B.J. , Lee S.H. , Lee I.S. , Lee H. , Lee H.S. , Lee J. , Oh Y.M. ,   The NEON collaboration
Published: October 2024

The Neutrino Elastic-scattering Observation with NaI(Tl)
experiment (NEON) aims to detect coherent elastic neutrino-nucleus
scattering (CEνNS) in a NaI(Tl) crystal using reactor anti-electron
neutrinos at the Hanbit nuclear power plant complex. A total of
13.3 kg of NaI(Tl) crystals were initially installed in December
2020 at the tendon gallery, 23.7 ± 0.3 m away from the reactor
core, which operates at a thermal power of 2.8 GW. Initial
engineering operation was performed from May 2021 to March 2022 and
observed unexpected photomultiplier-induced noise and a decreased
light yield that were caused by leakage of liquid scintillator into
the detector due to weakness of detector encapsulation. We upgraded
the detector encapsulation design to prevent the leakage of the
liquid scintillator. Meanwhile two small-sized detectors were
replaced with larger ones resulting in a total mass of 16.7 kg.
With this new design implementation, the detector system has been
operating stably since April 2022 for over a year without detector
gain drop. In this paper, we present an improved crystal
encapsulation design and stability of the NEON experiment.
3D printed feathers with embedded aerodynamic sensing
Authors: Tu Ruowen , Delplanche Rémy A , Tobalske Bret W , Inman Daniel J , Sodano Henry A
Published: October 2024

Bird flight is often characterized by outstanding aerodynamic efficiency, agility and adaptivity in dynamic conditions. Feathers play an integral role in facilitating these aspects of performance, and the benefits feathers provide largely derive from their intricate and hierarchical structures. Although research has been attempted on developing membrane-type artificial feathers for bio-inspired aircraft and micro air vehicles (MAVs), fabricating anatomically accurate artificial feathers to fully exploit the advantages of feathers has not been achieved. Here, we present our 3D printed artificial feathers consisting of hierarchical vane structures with feature dimensions spanning from 10−2 to 102 mm, which have remarkable structural, mechanical and aerodynamic resemblance to natural feathers. The multi-step, multi-scale 3D printing process used in this work can provide scalability for the fabrication of artificial feathers tailored to the specific size requirements of aircraft wings. Moreover, we provide the printed feathers with embedded aerodynamic sensing ability through the integration of customized piezoresistive and piezoelectric transducers for strain and vibration measurements, respectively. Hence, the 3D printed feather transducers combine the aerodynamic advantages from the hierarchical feather structure design with additional aerodynamic sensing capabilities, which can be utilized in future biomechanical studies on birds and can contribute to advancements in high-performance adaptive MAVs.
Slow post-fire carbon balance recovery despite increased net uptake rates in Alaskan tundra
Authors: Hung Jacqueline K Y , Arndt Kyle A , Murphy Patrick , Montemayor Marco , Rodenhizer Heidi , Ludwig Sarah , Rogers Brendan M , Natali Susan M
Published: October 2024

Increasing wildfire occurrence and intensity have immediate effects on northern ecosystems due to combustion of aboveground vegetation and belowground soil organic matter. These immediate impacts have indirect and longer term effects, including deepening of the active layer, changes in soil decomposition rates, and shifts in plant community composition. Despite the increasing fire impacts across the tundra region, the implications of wildfire on ecosystem carbon balance are not well understood. Using paired eddy covariance towers in unburned and burned tundra, we examined the effects of a 2015 wildfire on carbon dioxide and methane fluxes in a wetland tundra ecosystem in the Yukon–Kuskokwim Delta, Alaska, from 2020 to 2022. Wildfire increased the amplitude and variability of carbon uptake and release on seasonal and annual timescales and increased the temperature sensitivity of soil respiration. Seven years post fire, there was annual net uptake in both unburned and burned tundra based on net ecosystem exchange, with the sink strength of burned tundra exceeding that of the unburned tundra by 1.18–1.64 times. However, when considering emissions, it would take approximately 86 years to recover the carbon lost from the wildfire itself. Soil moisture was a dominant driver of fluxes and positively associated with higher rates of carbon dioxide uptake and release and methane release. This study underscores the importance of understanding the effects of wildfire-induced shifts on tundra carbon cycling, allowing better predictions of long-term landscape-scale climate feedbacks as the climate continues to warm.
Grassland albedo as a nature-based climate prospect: the role of growth form and grazing
Authors: McGregor S , Cromsigt J P G M , te Beest M , Chen J , Roy D P , Hawkins H-J , Kerley G I H
Published: October 2024

Nature-based solutions for mitigating climate change focus largely on land management to reduce carbon emissions and enhance carbon sequestration. Tree planting, commonly advocated for carbon offset, threatens grassland biodiversity and may induce positive radiative forcing (warming) by lowering albedo. Before making decisions about land-use changes in grasslands, an understanding of the fine-scale albedo of grassy versus woody vegetation is needed. Existing satellite-based albedo products offer global coverage with temporally fine, but spatially coarse, resolution, whereas fine-scale in situ grassland albedo data are sparse. We examined the hypotheses that albedo varies seasonally between grass type patches, between shrub and grass patches, and with grazing at the patch scale. Using a tripod-mounted albedometer, we quantified albedo of seven distinct grassland patches in South Africa’s eastern Karoo during early and late dormancy and growing seasons. Patches included intensely-grazed grazing lawn (Cynodon dactylon), grazed and less-grazed red tussock grass (Themeda triandra), grazed and less-grazed white tussock grass (Eragrostis lehmanniana), shrub (Pentzia incana) encroached grass, and bare ground. Season influenced albedo in all patches and, additionally, we found strong differences for the same period between years due to varying rainfall and temperature patterns. For grass-dominated patches, albedo differences were most pronounced during early dormancy, likely due to an effect of grass inflorescences. Albedo of intensely-grazed grazing lawns was consistently higher than other patches, except during early dormancy when white tussock grass albedo was equally high. We found no albedo difference between grazed and less-grazed tussock patches of either red or white grass. Shrub-encroached patches exhibited consistently lower albedo than other patches. Our findings underscore the nuanced relationship between grassland patches and albedo, with shrub encroachment, proposed afforestation, and certain grasses possibly increasing warming potential through reduced albedo. As climate initiatives extend into grasslands, understanding these patterns is essential for climate change mitigation and grassland conservation.
Lidar-derived estimates of boreal shrub biomass in Southcentral Alaska
Authors: Martin Kaili A , Dial Roman J , Cook Bruce D , Morton Douglas C , Larson Erin I , Andersen Hans-Erik
Published: October 2024

Despite widespread observations of shrub proliferation and expansion (shrubification), few studies quantify shrub biomass at the regional scale. Here we describe and implement a two-part modeling approach to estimate and map tall shrub (diameter at root collar > 2.5 cm) expected aboveground biomass, or E[SHB], across a 16.6 million ha boreal region where shrubification occurs in wetlands and subalpine ecosystems. Using n = 384 field plots nested within m= 11 study sites across southcentral Alaska, we constructed random forest models of the probability (pSH) that shrub wood volume surpasses tree wood volume, and generalized additive models of aboveground biomass of tall shrubs (SHB) using rasterized aerial lidar variables collected by NASA Goddard’s Lidar, Hyperspectral, and Thermal (G-LiHT) Airborne Imager, together with gridded climate data from a Parameter-elevation Regressions on Independent Slopes Model 30-year normal climatology (PRISM). Applying those models to G-LiHT tiles, then averaging across tiles within n = 843 watersheds covering 9.2 million ha, we estimated that below 1000 m asl, the area-weighted mean value of E[SHB] = pSH x SHB = 6.6 Mg ha−1 with sd = 4.5 Mg ha−1. This is the first study to estimate current shrub biomass density at the regional scale in southcentral Alaska and serves as a biomass baseline for measuring and modeling aboveground carbon fluxes where plant communities are undergoing climate-driven change.
Multi-headed lattices and Green functions
Authors: Chen Qipin , Chern Shane , Jiu Lin
Published: October 2024

Lattice geometries and random walks on them are of great interest for their applications in different fields such as physics, chemistry, and computer science. In this work, we focus on multi-headed lattices and study properties of the Green functions for these lattices such as the associated differential equations and the Pólya numbers. In particular, we complete the analysis of three missing cases in dimensions no larger than five. Our results are built upon an automatic machinery of creative telescoping.
Optimal circular states
Authors: Luo Shunlong , Tang Siting , Zhang Yue
Published: October 2024

In quantum optics, superpositions of coherent states, such as the Schrödinger cat states and compass states, and more generally, circular states, have attracted widespread attention due to their nice properties and significant applications. Concerning circular states, a natural question arises as what are the optimal parameters in these states for maximally achieving certain specified quantum features such as average photon number and nonclassicality. It turns out that this issue is highly nontrivial and subtle. In this work, we investigate optimal circular states for average photon number, and determine the optimal parameters by a combination of analytical and numerical methods. In particular, we establish several analytical results and also some rather detailed numerical results. We tabulate some numerical results, which may be useful in both theoretical and experimental studies of superpositions of coherent states.
A universal formula for the entanglement asymmetry of matrix product states
Authors: Capizzi Luca , Vitale Vittorio
Published: October 2024

Symmetry breaking is a fundamental concept in understanding quantum phases of matter, studied so far mostly through the lens of local order parameters. Recently, a new entanglement-based probe of symmetry breaking has been introduced under the name of entanglement asymmetry, which has been employed to investigate the mechanism of dynamical symmetry restoration. Here, we provide a universal formula for the entanglement asymmetry of matrix product states with finite bond dimension, valid in the large volume limit. We show that the entanglement asymmetry of any compact—discrete or continuous—group depends only on the symmetry breaking pattern, and is not related to any other microscopic features.
Conservation of Ramsey’s theorem for pairs and well-foundedness
Authors: Le Houérou Quentin , Patey Ludovic Levy , Yokoyama Keita
Published: October 2024

In this article, we prove that Ramsey’s theorem for pairs and two colors is

Π
1
1

\Pi ^1_1

-conservative over 

R
C
A

0

+

B

Σ
2
0

+

W
F

(

ϵ
0

)

\mathsf {RCA}_0 + \mathsf {B}\Sigma ^0_2 + \mathsf {WF}(\epsilon _0)

and over 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="sans-serif upper R sans-serif upper C sans-serif upper A Subscript 0 Baseline plus sans-serif upper B normal upper Sigma 2 Superscript 0 plus union Underscript n Endscripts sans-serif upper W sans-serif upper F left-parenthesis omega Subscript n Superscript omega Baseline right-parenthesis">

R
C
A

0

+

B

Σ
2
0

+

⋃
n

W
F

(

ω
n
ω

)

\mathsf {RCA}_0 + \mathsf {B}\Sigma ^0_2 + \bigcup _n \mathsf {WF}(\omega ^\omega _n)

. These results improve theorems from Chong, Slaman and Yang [Adv. Math. 308 (2017), pp. 121–141] and Kołodziejczyk and Yokoyama [In search of the first-order part of Ramsey’s theorem for pairs, Springer, Cham, 2021] and belong to a long line of research towards the characterization of the first-order part of Ramsey’s theorem for pairs.
Optimal rigidity estimates for varifolds almost minimizing the Willmore energy
Authors: Bi Yuchen , Zhou Jie
Published: October 2024

For an integral

2
2

-varifold

V
=

v
_

(
Σ
,

θ

⩾
1

)

V=\underline {v}(\Sigma ,\theta _{\geqslant 1})

in

R

n

\mathbb {R}^n

with generalized mean curvature

H
∈

L
2

H\in L^2

such that

μ
(

R

n

)
=
4
π

\mu (\mathbb {R}^n)=4\pi

and

∫

Σ

|

H

|

2

d
μ
⩽
16
π
(
1
+

δ
2

)

\int _{\Sigma }|H|^2d\mu \leqslant 16\pi (1+\delta ^2)

, we show that

Σ
\Sigma

is

W

2
,
2

W^{2,2}

close to the standard embedding of the round sphere in a quantitative way when

δ
>

δ
0

≪
1

\delta > \delta _0\ll 1

. For

n
=
3

n=3

, we prove that the sharp constant is

δ
0
2

=
2
π

\delta _0^2=2\pi

.
Rapid evasive behaviors of diamondback moth larvae against ants
Authors: Ito Kazuya , Yano Shuichi
Published: October 2024

Larvae of the diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) wriggle vigorously backward when physically stimulated. To explore whether this behavior is effective against ant attacks on their host plants with three-dimensional structures, we experimentally observed DBM larval movements and consequences thereof when attacked by Formica japonica (Hymenoptera: Formicidae) ants on the upper and lower surfaces of host plant leaves. On the upper surfaces of leaves, DBM larvae wriggled backward in response to ant attacks, and most larvae hung from leaf edges by spinning silk threads. On the lower surfaces of leaves, DBM larvae did not wriggle backward but immediately hung from the lower surface in response to attacks. No ants were able to pursue hanging larvae. We conclude that wriggling backward by DBM larvae belongs to a sequence of evasive movements against ant attacks on upper leaf surfaces. To our knowledge, this is the first report of combined wriggling and hanging behaviors by Lepidopteran larvae that are effective against ants in three-dimensional habitats.
Novel multi-omics deconfounding variational autoencoders can obtain meaningful disease subtyping
Authors: Li Zuqi , Katz Sonja , Saccenti Edoardo , Fardo David W , Claes Peter , Martins dos Santos Vitor A P , Van Steen Kristel , Roshchupkin Gennady V
Published: October 2024

Unsupervised learning, particularly clustering, plays a pivotal role in disease subtyping and patient stratification, especially with the abundance of large-scale multi-omics data. Deep learning models, such as variational autoencoders (VAEs), can enhance clustering algorithms by leveraging inter-individual heterogeneity. However, the impact of confounders—external factors unrelated to the condition, e.g. batch effect or age—on clustering is often overlooked, introducing bias and spurious biological conclusions. In this work, we introduce four novel VAE-based deconfounding frameworks tailored for clustering multi-omics data. These frameworks effectively mitigate confounding effects while preserving genuine biological patterns. The deconfounding strategies employed include (i) removal of latent features correlated with confounders, (ii) a conditional VAE, (iii) adversarial training, and (iv) adding a regularization term to the loss function. Using real-life multi-omics data from The Cancer Genome Atlas, we simulated various confounding effects (linear, nonlinear, categorical, mixed) and assessed model performance across 50 repetitions based on reconstruction error, clustering stability, and deconfounding efficacy. Our results demonstrate that our novel models, particularly the conditional multi-omics VAE (cXVAE), successfully handle simulated confounding effects and recover biologically driven clustering structures. cXVAE accurately identifies patient labels and unveils meaningful pathological associations among cancer types, validating deconfounded representations. Furthermore, our study suggests that some of the proposed strategies, such as adversarial training, prove insufficient in confounder removal. In summary, our study contributes by proposing innovative frameworks for simultaneous multi-omics data integration, dimensionality reduction, and deconfounding in clustering. Benchmarking on open-access data offers guidance to end-users, facilitating meaningful patient stratification for optimized precision medicine.
Cancerous time estimation for interpreting the evolution of lung adenocarcinoma
Authors: Han Yourui , Chen Bolin , Bian Jun , Kang Ruiming , Shang Xuequn
Published: October 2024

The evolution of lung adenocarcinoma is accompanied by a multitude of gene mutations and dysfunctions, rendering its phenotypic state and evolutionary direction highly complex. To interpret the evolution of lung adenocarcinoma, various methods have been developed to elucidate the molecular pathogenesis and functional evolution processes. However, most of these methods are constrained by the absence of cancerous temporal information, and the challenges of heterogeneous characteristics. To handle these problems, in this study, a patient quasi-potential landscape method was proposed to estimate the cancerous time of phenotypic states’ emergence during the evolutionary process. Subsequently, a total of 39 different oncogenetic paths were identified based on cancerous time and mutations, reflecting the molecular pathogenesis of the evolutionary process of lung adenocarcinoma. To interpret the evolution patterns of lung adenocarcinoma, three oncogenetic graphs were obtained as the common evolutionary patterns by merging the oncogenetic paths. Moreover, patients were evenly re-divided into early, middle, and late evolutionary stages according to cancerous time, and a feasible framework was developed to construct the functional evolution network of lung adenocarcinoma. A total of six significant functional evolution processes were identified from the functional evolution network based on the pathway enrichment analysis, which plays critical roles in understanding the development of lung adenocarcinoma.
SELF-Former: multi-scale gene filtration transformer for single-cell spatial reconstruction
Authors: Chen Tianyi , Wei Xindian , Xie Lianxin , Zhang Yunfei , Liu Cheng , Shen Wenjun , Wu Si , Wong Hau-San
Published: October 2024

The spatial reconstruction of single-cell RNA sequencing (scRNA-seq) data into spatial transcriptomics (ST) is a rapidly evolving field that addresses the significant challenge of aligning gene expression profiles to their spatial origins within tissues. This task is complicated by the inherent batch effects and the need for precise gene expression characterization to accurately reflect spatial information. To address these challenges, we developed SELF-Former, a transformer-based framework that utilizes multi-scale structures to learn gene representations, while designing spatial correlation constraints for the reconstruction of corresponding ST data. SELF-Former excels in recovering the spatial information of ST data and effectively mitigates batch effects between scRNA-seq and ST data. A novel aspect of SELF-Former is the introduction of a gene filtration module, which significantly enhances the spatial reconstruction task by selecting genes that are crucial for accurate spatial positioning and reconstruction. The superior performance and effectiveness of SELF-Former’s modules have been validated across four benchmark datasets, establishing it as a robust and effective method for spatial reconstruction tasks. SELF-Former demonstrates its capability to extract meaningful gene expression information from scRNA-seq data and accurately map it to the spatial context of real ST data. Our method represents a significant advancement in the field, offering a reliable approach for spatial reconstruction.
Cuticular morphology of Schinus L. and related genera
Authors: Matel Theodore P , Gandolfo Maria A , Mitchell John D
Published: October 2024

The Anacardiaceae are a characteristic angiosperm family of the Neotropics where they comprise ~32 genera and 200 species (~80 genera and 800 species globally). Among Neotropical Anacardiaceae genera, Schinus has the greatest species richness with 42 species distributed from tropical latitudes of Brazil and Peru south to the temperate steppe, matorral, and Valdivian temperate forest communities of Patagonia. Previous studies have found some anatomical and morphological leaf traits (e.g. simple vs. compound leaf organization) useful in characterizing lineages within Schinus, but also document traits that are homoplastic within the genus (e.g. stomatal distribution) and convergent among Schinus and its close relatives Lithrea and Mauria (e.g. mesophyll arrangement). Here, we present a survey of leaf cuticular traits in 53 species of Schinus and its closest relatives Lithrea, Mauria, and Euroschinus based on characters observed with scanning electron and optical light microscopy. We use ordinated Bray–Curtis distances based on 18 characters and 2D nonmetric multidimensional scaling to show that cuticular morphology resolves the three most diverse genera, Euroschinus, Mauria, and Schinus, but does not resolve intrageneric sections of Schinus. We propose that a distinctive acuminate gland type occurring only within Euroschinus may constitute a potential synapomorphy for this genus. Within Schinus, we find inconsistency in stomatal distribution among specimens of a single species, among species of a single section, and between sections of the genus, and suggest that current evidence is insufficient to implicate either phenotypic plasticity or homoplasy as the causative mechanism of this variation.
Facial oedema and necrotic ulcers: a cutaneous reaction to liraglutide
Authors: Santana-Gutiérrez Adalberto , Bautista-Gómez Andrea J , González-Guajardo Jorge A , Rosales-Solís Gloria M , Ocampo-Candiani Jorge , Muñoz-Garza Fania Z
Published: October 2024

Owing to rising obesity rates, new drugs like liraglutide, a glucagon-like peptide-1 receptor agonist, are increasingly used for weight loss. While liraglutide-related skin reactions are rare, this case report describes a 44-year-old man with severe facial oedema and necrotic ulcers following liraglutide administration. Despite having taken the drug 5 years earlier without issue, the patient developed symptoms after receiving two doses. A skin biopsy revealed necrosis and inflammation, and the condition was successfully treated with steroids. The report underscores the need to consider cutaneous adverse effects in patients using liraglutide.