bluuebunny/crossref_metadata_2025 huggingface dataset:
In-plane thermoelectric properties of graphene/xBN/graphene van der Waals heterostructures
Authors: Makumi Sylvester W , Bem Daniel , Musila Nicholas , Foss Cameron , Aksamija Zlatan
Published: February 2023

2D materials have attracted broad attention from researchers for their unique electronic properties, which may be been further enhanced by combining 2D layers into vertically stacked van der Waals heterostructures (vdWHs). Among the superlative properties of 2D systems, thermoelectric (TE) energy conversion promises to enable targeted energy conversion, localized thermal management, and thermal sensing. However, TE conversion efficiency remains limited by the inherent tradeoff between conductivity and thermopower. In this paper, we use first-principles calculation to study graphene-based vdWHs composed of graphene layers and hexagonal boron nitride (h-BN). We compute the electronic band structures of heterostructured systems using Quantum Espresso and their TE properties using BoltzTrap2. Our results have shown that stacking layers of these 2D materials opens a bandgap, increasing it with the number of h-BN interlayers, which significantly improves the power factor (PF). We predict a PF of ∼1.0 × 1011 W K−2 m s for the vdWHs, nearly double compared to 5 × 1010 W K−2 m s that we obtained for single-layer graphene. This study gives important information on the effect of stacking layers of 2D materials and points toward new avenues to optimize the TE properties of vdWHs.
Indoor radon survey in Whitehorse, Canada, and dose assessment
Authors: Hansen Violeta , Sabo Angela , Korn Juergen , MacLean Douglas , Rigét Frank Farsø , Clausen Daniel Spelling , Cubley Joel
Published: February 2023

Radon-222 (222Rn) and its decay products are the primary sources of a population’s exposure to background ionizing radiation. Radon decay products are the leading cause of lung cancer for non-smokers and the second leading cause of lung cancer after smoking for smokers. A community-driven long-term radon survey was completed in 232 residential homes in different subdivisions of Whitehorse, the capital of the Yukon, during the heating season from November to April in 2016–2017 and in 2017–2018. Radon concentrations were measured in living rooms and bedrooms on ground floors. The arithmetic and geometric means of indoor radon activity concentrations in different subdivisions of Whitehorse ranged from 52 ± 0.6 Bq m−3 and 37 ± 2.3 Bq m−3 in the Downtown area of Whitehorse to 993.0 ± 55.0 Bq m−3 and 726.2 ± 2.4 Bq m−3 in Wolf Creek. Underlying geology and glacial surfaces may partly explain these variations of indoor radon concentrations in subdivisions of Whitehorse. A total of 78 homes (34.0%) had radon concentrations higher than 100 Bq m−3, 47 homes (20.5%) had concentrations higher than 200 Bq m−3 and 33 homes (14.4%) had concentrations higher than 300 Bq m−3. The indoor radon contribution to the annual effective inhalation dose to residents ranged from 3.0 mSv in the Downtown area to 51.0 mSv in Wolf Creek. The estimated annual average dose to adults in Whitehorse, Yukon, is higher than the world’s average annual effective dose of 1.3 mSv due to the inhalation of indoor radon. The annual radon inhalation effective dose was assessed using radon measurements taken during winter; hence the assessed dose may be overestimated. Cost-efficient mitigation methods are available to reduce radon in existing buildings and to prevent radon entry into new buildings.
Weak signal enhancement for rolling bearing fault diagnosis based on adaptive optimized VMD and SR under strong noise background
Authors: Luo Jianqing , Wen Guangrui , Lei Zihao , Su Yu , Chen Xuefeng
Published: February 2023

Owing to the nonlinearity and nonstationarity of the bearing fault signal, it is difficult to identify fault characteristics under the influence of a strong noise environment. The extraction of early weak fault features is critical for the reliability of bearing operations. Therefore, an urgent problem is reasonable noise reduction and feature enhancement in weak-signal processing. Traditional variational modal decomposition (VMD) and stochastic resonance (SR) are commonly applied to detect weak signals in fault diagnosis. The VMD method can decompose the signal into several intrinsic mode functions (IMFs) to effectively reduce the modal aliasing problem. However, uniform standards for the key parameters of decomposition and the selection of the optimal IMF after decomposition are lacking. Meanwhile, some disadvantages of SR still exist; for example, the interference of multiscale noise may lead to false detection by incorrect selection of high-pass filter parameters, and the system parameters are not adaptive to different signals to achieve the best response output. To better address the weak signal feature enhancement, a novel rolling bearing fault diagnosis method combining adaptive VMD and SR by improved differential search (IDS) optimization is proposed. First, the bearing fault signal is decomposed into several IMFs using the IDS-VMD. Second, the feature information of the fault signal is retained and reconstructed using the correlation kurtosis for sensitive modal extraction. Furthermore, the fault features of the reconstructed signal are effectively enhanced by the variable-step IDS-SR, which can reasonably transfer the noise energy of the input components to the fault characteristic frequency. Finally, the periodic pulse can be observed in the corresponding envelope spectrum. The simulated and experimental data show that the proposed method can not only effectively extract the signal feature information in the actual fault but also realize early weak fault diagnosis of rolling bearings more accurately.
Insulated rail joint (IRJ) contact characterisation-an ultrasonic reflectometry approach for a cross-material interface
Authors: Zhou Lu , Luo Yun-Ke , Lewis Roger
Published: February 2023

Vehicle–track interaction at insulated rail joints (IRJs) plays a significant role in the wear evolvement and damage of the IRJ components. It is, however, challenging to characterise the contact conditions within the region non-destructively and accurately using experimental tools, especially when the IRJ contact involves both wheel–rail and wheel–endpost contact pairs. This study presents an ultrasonic technique to monitor and characterise static IRJ contacts in a non-invasive manner. The proposed ultrasonic reflectometry technique can realise high-resolution visualisation of contact patch and contact pressure distribution for both wheel–rail contact and wheel–endpost contact, by striking a beam of focused ultrasonic signals at the contact interface. Different data post-processing strategies are applied for the two types of contacts and a deconvolution algorithm is applied to rectify the measurements near the rail–endpost boundary. The ultrasonic measurements are verified through finite element simulations and the results show good agreement with each other in terms of both contact area and contact pressure level. It is expected that the proposed ultrasonic approach can be a reliable tool to assist in revealing the contact behaviour of IRJs more profoundly.
Optimized hydrodynamic interactions in phalanx school arrays of accelerated thunniform swimmers
Authors: Abouhussein Ahmed , Peet Yulia T
Published: February 2023

Optimal fish array hydrodynamics in accelerating phalanx schools are investigated through a computational framework which combines high fidelity Computational Fluid Dynamics (CFD) simulations with a gradient free surrogate-based optimization algorithm. Critical parameters relevant to a phalanx fish school, such as midline kinematics, separation distance and phase synchronization, are investigated in light of efficient propulsion during an accelerating fish motion. Results show that the optimal midline kinematics in accelerating phalanx schools resemble those of accelerating solitary swimmers. The optimal separation distance in a phalanx school for thunniform biologically-inspired swimmers is shown to be around 2L (where L is the swimmer’s total length). Furthermore, separation distance is shown to have a stronger effect, ceteris paribus, on the propulsion efficiency of a school when compared to phase synchronization.
Valence subbands profile regulation in AlGaN quantum well based on k·p theory
Authors: Wang Xianjun , Jiang Ke , Sun Xiaojuan , Zhang Zi-Hui , Chen Yuxuan , Wang Bingxiang , Li Dabing
Published: February 2023

The profiles for the valence subbands of an AlGaN-based quantum well (QW) is investigated by considering quantum confinement effect (QCE) and strain through the
k
·
p
theory. We have found that to increase the QCE and the compressive strain would rise the relative position of the heavy hole (HH) subband to the crystal field splitting hole (CH) subband in the valence band of the QW. However, although the variation trend of the relative valance subbands position is similar, the underlying mechanisms of the modulation by the QCE and strain are not the same. In addition, we have found that if the energy level between the HH and the CH subbands is close at a certain
k

t

point, the subband anti-crossing effect of the QW will enhance their coupling level, causing dipole moments from the conduction subbands to these valence subbands transformation between each other. These results can provide important basis for the active region design of some AlGaN-based short wavelength, high carrier injection, or monolithic integration optoelectronic devices.
Synergetic role of Ni and GOns to improve the microstructure and mechanical creep rate of Sn-5.0Sb-0.7Cu solder alloy
Authors: Mousa M M , Mahmoud M A , El-Zhery M M , Sobhy M
Published: February 2023

The role of minor additions of Ni and GOns to Sn- 5 wt% Sb- 0.7 wt% Cu (SSC-507) has been explored. Findings of scanning electron microscopy (SEM), energy dispersive x-ray spectrometry (EDX), and x-ray diffractometry (XRD) display the new phases like (Cu,Ni)6Sn5 and the size decrement of β-Sn grains. A slight increase in the melting temperature was observed using differential scanning calorimetry (DSC) analysis due to adding Ni (ΔTm = 1.02 °C) and GOns (ΔTm = 0.75 °C). Interestingly, 0.1 wt% Ni addition reduced the under-cooling by ∼28%, whenever adding of 0.1 wt% GOns enhanced the under-cooling by ∼115%. The average size of β-Sn grains of SSC-507 plain solder was decreased from ∼150 to ∼70 μm due to adding of Ni and then GOns. The enhanced creep resistance of SSC-Ni-GOns alloy motivated the values of creep fracture and enhanced the stress exponent parameters (n) by ∼27%. The outcomes of tensile creep examination demonstrate that increasing levels of stress and testing temperatures raise the steady-state creep rates for all tested alloys. The average activation energy (E) for the three solders ranged from ∼46.5 kJ mol−1 to ∼54.3 kJ mol−1 which close to that of pipe-diffusion mechanism in Sn based solder alloy.
Model for anisotropic compact stars via Chaplygin equation of state in Tolman space-time
Authors: Kumar Mahesh , Kumar Jitendra
Published: February 2023

In this work, we construct a unique anisotropic solution for spherically symmetric spacetime by investigating the Chaplygin EOS for the anisotropic fluid distribution. For generating the solutions, we have used Tolman metric potential Tolman R C (1939Phys. Rev.,55, 364–373) to solve the field equations. The anisotropic solution gives well behaved results and the energy conditions are fully satisfied. The TOV equation, Harrison-Zeldovik-Novikov criteria, and adiabatic index have been used to verify the stability of the model. Because this model meets all of these characteristics, it may be used to investigate realistic compact objects. We have also used this model to calculate the masses and radii of compact stars like Her X-1, 4U 1538-52, SAX J1808.4-3658, and LMC X-4, and found that these values were consistent with observational data which was derived using the provided solution.
Evidence of fresh cosmic ray in galactic plane based on DAMPE measurement of B/C and B/O ratios
Authors: Zhang Pei-Pei , He Xin-Yu , Liu Wei , Guo Yi-Qing
Published: February 2023

More and more experiments have identified that the energy spectra of both primary and secondary cosmic-rays exhibit a hardening above ∼ 200 GV. More recently, the DAMPE experiment has reported a hardening of boron-to-carbon ratio at 200 GV. These signs call for modifications of the conventional cosmic-ray (CR) picture. In this work, we propose that the plethoric secondary cosmic rays, for example, boron, antiprotons, originate from the hadronic interactions of freshly accelerated cosmic rays with the interstellar gas near the sources. We find that secondary-to-primary ratios, for example, boron-to-carbon, boron-to-oxygen and antiproton-to-proton ratios, can be well described. The measurements of electrons and positrons can also be accounted for.
Spatial search by continuous-time quantum walk on truncated simplex lattices
Authors: Zhu Xuanmin , Deng Yuanchun , Zhang Dezheng , Gao Runping , Wei Qun , Luo Zijiang
Published: February 2023

Quantum search via continuous-time quantum walk on truncated simplex lattices is an important example of the quantum search on the structured database. In this letter, when the search target is a set of the marked vertices, the run time of the quantum search and the critical jumping rates are derived. Quantum search with the partial information of the location of the marked vertex is also discussed. Furthermore, with the edge weights suitably adjusted, the three-stage search process can be optimized into a two-stage quantum search algorithm on the second-order truncated simplex lattice.
Limiting Magnitudes of the Wide Field Survey Telescope (WFST)
Authors: Lei Lei , Zhu Qing-Feng , Kong Xu , Wang Ting-Gui , Zheng Xian-Zhong , Shi Dong-Dong , Fan Lu-Lu , Liu Wei
Published: February 2023

Expected to be of the highest survey power telescope in the northern hemisphere, the Wide Field Survey Telescope (WFST) will begin its routine observations of the northern sky since 2023. WFST will produce a lot of scientific data to support the researches of time-domain astronomy, asteroids and the solar system, galaxy formation and cosmology and so on. We estimated that the 5σ limiting magnitudes of WFST with 30 s exposure are u = 22.31 mag, g = 23.42 mag, r = 22.95 mag, i = 22.43 mag, z = 21.50 mag, w = 23.61 mag. The above values are calculated for the conditions of airmass = 1.2, seeing = 0.″75, precipitable water vapor = 2.5 mm and Moon-object separation = 45° at the darkest New Moon night of the Lenghu site (V = 22.30 mag, Moon phase θ = 0°). The limiting magnitudes in different Moon phase conditions are also calculated. The calculations are based on the empirical transmittance data of WFST optics, the vendor provided CCD quantum efficiency, the atmospherical model transmittance and spectrum of the site. In the absence of measurement data such as sky transmittance and spectrum, we use model data.
3D Kinematics of Classical Cepheids According to Gaia EDR3 Catalog
Authors: Bobylev V. V. , Bajkova A. T.
Published: February 2023

The kinematics of about 2000 classical Cepheids of the Milky Way with data from Gaia EDR3 catalog has been studied. For some of these stars, there are line-of-sight velocities. On the basis of the nonlinear rotation model, the parameters of the rotation curve of the Galaxy were determined. The circular linear rotation velocity of the near-solar neighborhood around the Galaxy center was V
0 = 236 ± 3 km s−1 for the assumed Sun’s galactocentric distance R
0 = 8.1 ± 0.1 kpc. Analysis of residual velocities of Cepheids based on the linear Ogorodnikov–Milne model showed the presence of the following significantly different from zero gradients: ∂U/∂x, ∂U/∂z, ∂V/∂x, ∂V/∂z and ∂W/∂x, which behave differently depending on the selection radius. The most interesting is the gradient ∂W/∂x ∼ − 0.5 ± 0.1 km s−1 kpc−1 (positive rotation of this star system around the Galactic axis y, Ω
y
) since the velocities W are free of Galactic rotation. Here we have an indirect influence of various effects leading to a perturbation of the vertical velocities of the Galactic disk stars. Based on a simpler model, a more accurate estimate of this rotation is obtained, Ω
y
= 0.51 ± 0.07 km s−1 kpc−1.
The new monolithic ASIC of the preshower detector for di-photon measurements in the FASER experiment at CERN
Authors: Gonzalez-Sevilla S.
Published: February 2023

The ForwArd Search ExpeRiment (FASER) is an experiment searching for new light and weakly-interacting particles at CERN’s Large Hadron Collider. FASER is composed of different sub-detectors, including silicon microstrip detectors, scintillator counters and an electromagnetic calorimeter. In this paper, a new preshower detector for the FASER experiment is presented. The new detector, based on monolithic pixel ASICs, will provide excellent spatial and time resolutions and a large charge dynamic range. First results from a prototype chip produced by IHP in 130 nm SiGe BiCMOS technology are shown.
A wide-band, high-resolution vacuum flat crystal spectrometer for LEAF facility
Authors: Wang W. , Shao C.J. , Yang Y. , Yu D.Y. , Xue Y.L. , Cai X.H.
Published: February 2023

A wide-band, high-resolution vacuum flat-crystal
spectrometer was developed for analyzing the x-rays spectra of
hollow atoms. The spectrometer was designed to cover an energy
dynamic range of 0.6 to 16 keV by combining different flat crystals
and an x-ray CCD detector mounted on a twistable bellows that could
modulate the Bragg angles ranging from 25° to 50°.The
performance of the spectrometer was evaluated in energy range of
3–12 keV by measuring the K and L x-rays generated by
10–30 keV electron beam collisions with solid titanium, silver and
gold targets, respectively. The typical resolving power of the
spectrometer is estimated to be around 103, with a single
exposure measurement range of 144–1411 eV and corresponding energy
resolution of 3.5–33.2 eV. This spectrometer could be utilized
to investigate the fine hyper-satellite line structure of hollow
atoms with 10 ≤ Z ≤ 26.
Fabrication of mechanical skeleton of small-diameter vascular grafts via rolling on water surface
Authors: Li Shuo , Yang Lei , Zhao Zijian , Wang Jie , Lv Hongying , Yang Xiaoniu
Published: February 2023

Mimicking the multilayered structure of blood vessels and constructing a porous inner surface are two effective approaches to achieve mechanical matching and rapid endothelialization to reduce occlusion in small-diameter vascular grafts. However, the fabrication processes are complex and time consuming, thus complicating the fabrication of personalized vascular grafts. A simple and versatile strategy is proposed to prepare the skeleton of vascular grafts by rolling self-adhesive polymer films. These polymer films are directly fabricated by dropping a polymer solution on a water surface. For the tubes, the length and wall thickness are controlled by the rolling number and position of each film, whereas the structure and properties are tailored by regulating the solution composition. Double-layer vascular grafts (DLVGs) with microporous inner layers and impermeable outer layers are constructed; a microporous layer is formed by introducing a hydrophilic polymer into a polyurethane (PU) solution. DLVGs exhibit a J-shaped stress–strain deformation profile and compliance comparable to that of coronary arteries, sufficient suture retention strength and burst pressure, suitable hemocompatibility, significant adhesion, and proliferation of human umbilical vein endothelial cells. Freshly prepared PU tubes exhibit good cytocompatibility. Thus, this strategy demonstrates potential for rapid construction of small-diameter vascular grafts for individual customization.
Design of novel bioadhesive chitosan film loaded with bimetallic gold-silver nanoparticles for antibiofilm and wound healing activity
Authors: Singh Chandrashekhar , Mehata Abhishesh Kumar , Vikas  , Tiwari Punit , Setia Aseem , Malik Ankit Kumar , Singh Sanjeev K , Tilak Ragini , Muthu Madaswamy S
Published: February 2023

Microbial infections and antibiotic resistance are among the leading causes of morbidity and mortality worldwide. The bimetallic chitosan (CS)-capped gold-silver nanoparticles (CS-AuAg-NPs) were prepared by the seeded growth synthesis technique. The nanoparticles were optimized for particle size (PS), zeta potential (ZP) and antibacterial activity by Box–Behnken design at three levels and three factors. The developed CS-AuAg-NPs were polydispersed with mean hydrodynamic PS in the range of 55 – 289 nm and ZP ranges from +8.53 mV to +38.6 mV. The optimized CS-AuAg-NPs found to have a minimum inhibitory concentration and minimal bactericidal concentration of 1.625 ± 0.68 and 3.25 ± 0.74 µg ml−1 towards multidrug resistant (MDR) Staphylococcus aureus ATCC 25923 (MDR AT) and 3.25 ± 0.93 and 3.25 ± 0.86 µg ml−1 towards MDR S. aureus clinical isolate MDR1695 (MDR CI) strain, respectively. The CS-AuAg-NPs were much more effective against MDR AT and MDR CI compared to clindamycin standard. The live/dead assay of clinical isolates strain demonstrated significant reduction of bacterial cells ∼67.52 folds compared to control group in 12 h. The hemolysis study suggested that CS-AuAg-NPs were non-hemolytic and safer for application in the wound. Furthermore, CS-AuAg-NPs were distributed in the CS film, which showed 87% wound recovery after 7 d in mice model. Hence, we concluded that CS-AuAg-NPs was safer and more effective against MDR bacteria and capable of skin regeneration in the infected wound.
Transnational agricultural land acquisitions threaten biodiversity in the Global South
Authors: Davis Kyle Frankel , Müller Marc F , Rulli Maria Cristina , Tatlhego Mokganedi , Ali Saleem , Baggio Jacopo A , Dell’Angelo Jampel , Jung Suhyun , Kehoe Laura , Niles Meredith T , Eckert Sandra
Published: February 2023

Agricultural large-scale land acquisitions have been linked with enhanced deforestation and land use change. Yet the extent to which transnational agricultural large-scale land acquisitions (TALSLAs) contribute to—or merely correlate with—deforestation, and the expected biodiversity impacts of the intended land use changes across ecosystems, remains unclear. We examine 178 georeferenced TALSLA locations in 40 countries to address this gap. While forest cover within TALSLAs decreased by 17% between 2000 and 2018 and became more fragmented, the spatio-temporal patterns of deforestation varied substantially across regions. While deforestation rates within initially forested TALSLAs were 1.5 (Asia) to 2 times (Africa) higher than immediately surrounding areas, we detected no such difference in Europe and Latin America. Our findings suggest that, whereas TALSLAs may have accelerated forest loss in Asia, a different mechanism might emerge in Africa where TALSLAs target areas already experiencing elevated deforestation. Regarding biodiversity (here focused on vertebrate species), we find that nearly all (91%) studied deals will likely experience substantial losses in relative species richness (−14.1% on average within each deal)—with mixed outcomes for relative abundance—due to the intended land use transitions. We also find that 39% of TALSLAs fall at least partially within biodiversity hotspots, placing these areas at heightened risk of biodiversity loss. Taken together, these findings suggest distinct regional differences in the nature of the association between TALSLAs and forest loss and provide new evidence of TALSLAs as an emerging threat to biodiversity in the Global South.
An exact formula for the variance of linear statistics in the one-dimensional jellium model
Authors: Flack Ana , Majumdar Satya N , Schehr Grégory
Published: February 2023

We consider the jellium model of N particles on a line confined in an external harmonic potential and with a pairwise one-dimensional Coulomb repulsion of strength α > 0. Using a Coulomb gas method, we study the statistics of

s
=
(
1

/

N
)

∑

i
=
1

N

f
(

x
i

)

where f(x), in principle, is an arbitrary smooth function. While the mean of s is easy to compute, the variance is nontrivial due to the long-range Coulomb interactions. In this paper we demonstrate that the fluctuations around this mean are Gaussian with a variance

Var

(
s
)
≈
b

/

N
3

for large N. In this paper, we provide an exact compact formula for the constant

b
=
1

/

(
4
α
)

∫

−
2
α

2
α

[

f

′

(
x
)

]
2

d
x

. In addition, we also calculate the full large deviation function characterizing the tails of the full distribution

for several different examples of f(x). Our analytical predictions are confirmed by numerical simulations.
Rail Structure Interaction Analysis for Providing CWR on Un-Ballasted Multi-Span Open Web Steel Girder Bridge
Authors: Prakash D Jeetendra , Sravana P , Rao P Srinivasa
Published: February 2023

Rail structure interaction (RSI) requires thorough study to understand the force transfer mechanism between the track and bridge components due to train vertical live loads, braking/traction loads and thermal loads accordingly. RSI analysis gives us an outline of the axial stress in rail, support reactions transferred to the bridge components and the relative displacement caused between the track and bridge. This paper investigates rail structure interaction analysis of unballasted multi-span steel through girder railway bridge carrying dedicated freight corridor (DFC) of 32.5t axle load. For this purpose, RSI analysis is performed as per the guidelines given in UIC774-3R [7] Code of Practice (International Union of Railways) for two different multi-span bridge with a span configuration of 7x63m and 6x48m respectively and the axial stress in rail, relative displacement between rail and bridge and support reactions transferred to the bridge components are calculated based on the span and stiffnesses of the bridges. From the analysis results, it shall be concluded whether to explore the possibility of providing a provision of continuous welded rail (CWR) on the bridge or to adopt switch expansion joints (SEJ) or other expansion devices accordingly.
Free Vibration Analysis of Symmetric and Asymmetric RCC Structures
Authors: Seeram Madhuri , Kumar Pramod
Published: February 2023

Symmetric and asymmetric structures behave differently under external loads even though they are of an equal number of stories or equal in dimensions. It is necessary to estimate the dynamic properties of the asymmetric structures carefully to avoid failure. Modal analysis for symmetric and asymmetric multi-storied reinforced concrete (RC) buildings is very essential to assess the dynamic characteristics of the structure. The plan asymmetric buildings with the shift of core from a central position to different positions and vertical asymmetry with the mass variation in vertical direction and setback stories are considered for the present study. Flexural beam elements are modelled to represent the columns. Two translations i.e., longitudinal, and transverse displacements of the building and rotation about the vertical axis of the structure are taken as global degrees of freedom at each node. The distance between the mass center and stiffness centre on each floor is taken as eccentricity. A finite element model is developed using MATLAB code to estimate the natural frequencies. Different RCC structures of 5 to 20-storied buildings are modelled by developing global stiffness and mass matrices based on the member connectivity. Eigen-value technique is used to estimate the natural frequencies. From the study it is observed that the natural period in asymmetric structures is found more than the symmetric building. The structure with setback also showed larger natural period.
Floquet topological phases on a honeycomb lattice using elliptically polarized light
Authors: Seshadri Ranjani
Published: February 2023

We study the effect of driving a two-dimensional honeycomb system out of equilibrium using an elliptically polarized light as a time-dependent perturbation. In particular, we try to understand the topological phase diagram of this driven system when the external drive is a vector potential given by

A
(
t
)
=
(

A

0
x

cos
(
Ω
t
)
,

A

0
y

cos
(
Ω
t
+

ϕ

0

)
)

. These topological phases are characterized by the Floquet Chern number which, in each of these phases, is related to the number of robust edge modes on a nanoribbon. We show that varying the ratio A
0x
/A
0y
of the external drive is a possible way to take the system from a trivial to a topological phase and vice versa.
Enhanced the sensitivity of one-dimensional photonic crystals infiltrated with cancer cells
Authors: Segovia-Chaves Francis , Carlos Trujillo Juan , Trabelsi Youssef
Published: February 2023

In this work, we use a one-dimensional photonic crystal as a biosensor composed of alternating GaAs and air layers. Within the cavity where they are infiltrated, the Normal, Jurkat, HeLa, PC-12, MDA-MB-231, and MCF-7 cells are bounded by layers of nanocomposite and graphene to increase biosensor sensitivity. The transmission spectrum was calculated using the transfer matrix method. We observed that, when the structural periodicity is broken, defect modes that characterize each cell are created. These defect modes move at a wavelength as the dielectric constant increases. Additionally, the separation between defect modes and bandwidth determines sensitivity, Q factor, and FOM, in which average values of 406.84 nm/RIU, 1765.53, and 535.44 were obtained, respectively, for normal light incidence. Regarding Transverse-Electric (TE) and Transverse-Magnetic (TM) polarization, the defect modes shift toward shorter wavelengths as the angle of incidence increases. For TE polarization, transmittance decreased and the distance between the modes increased. At a 50° angle, sensitivity, Q factor, and FOM increased up to 497.55 nm/RIU, 3182.02, and 1401.25, respectively. Conversely, at a 50° angle in TM polarization, sensitivity remained constant at a value of 407 nm/RIU, along with increased transmittance and decreased performance. Finally, sensitivity and performance were optimized by modifying the cavity thickness value at an incidence angle of 30° for TE polarization, and at an incidence angle of 10° for TM polarization. In both cases, the increased cavity thickness shifted the defect modes toward longer wavelengths while increasing sensitivity up to 495.75 nm/RIU for TE and 451.33 nm/RIU for TM.
Helical streamers guided by surface electromagnetic standing waves
Authors: ZOU Dandan , TU Chensheng , CUI Chunmei
Published: February 2023

The streamer that is driven by the specific pulse DC discharge parameters can stably form a three-dimensional helical plasma channel in a long dielectric tube in the low-temperature plasma experiment, in cases when there were neither external background magnetic field or other factors that destroyed the poloidal symmetry of the tube. The formation mechanism and chirality of helical streamers are discussed according to the surface electromagnetic standing wave theory. The shape of the helical streamers and the characteristics of helical branches are quantitatively analyzed to further expand the application of plasma and streamer theory in the helix problem and chiral catalytic synthesis.
The Dirac impenetrable barrier in the limit point of the Klein energy zone
Authors: De Vincenzo Salvatore
Published: February 2023

We reanalyze the problem of a 1D Dirac single particle colliding with the electrostatic potential step of height V
0 with a positive incoming energy that tends to the limit point of the so-called Klein energy zone, i.e. E → V
0 − mc
2, for a given V
0. In such a case, the particle is actually colliding with an impenetrable barrier. In fact, V
0 → E + mc
2, for a given relativistic energy E( < V
0), is the maximum value that the height of the step can reach and that ensures the perfect impenetrability of the barrier. Nevertheless, we note that, unlike the nonrelativistic case, the entire eigensolution does not completely vanish, either at the barrier or in the region under the step, but its upper component does satisfy the Dirichlet boundary condition at the barrier. More importantly, by calculating the mean value of the force exerted by the impenetrable wall on the particle in this eigenstate and taking its nonrelativistic limit, we recover the required result. We use two different approaches to obtain the latter two results. In one of these approaches, the corresponding force on the particle is a type of boundary quantum force. Throughout the article, various issues related to the Klein energy zone, the transmitted solutions to this problem, and impenetrable barriers related to boundary conditions are also discussed. In particular, if the negative-energy transmitted solution is used, the lower component of the scattering solution satisfies the Dirichlet boundary condition at the barrier, but the mean value of the external force when V
0 → E + mc
2 does not seem to be compatible with the existence of the impenetrable barrier.
Biskyrmion-based artificial neuron
Authors: Ribeiro de Assis Ismael , Mertig Ingrid , Göbel Börge
Published: February 2023

Magnetic skyrmions are nanoscale magnetic whirls that are highly stable and can be moved by currents. They have led to the prediction of a skyrmion-based artificial neuron device with leak-integrate-fire functionality. However, so far, these devices lack a refractory process, estimated to be crucial for neuronal dynamics. Here we demonstrate that a biskyrmion-based artificial neuron overcomes this insufficiency. When driven by spin-orbit torques, a single biskyrmion splits into two subskyrmions that move towards a designated location and can be detected electrically, ultimately resembling the excitation process of a neuron that fires. The attractive interaction of the two skyrmions leads to a unique trajectory: Once they reach the detector area, they automatically return to the center to reform the biskyrmion but on a different path. During this reset period, the neuron cannot fire again. Our suggested device resembles a biological neuron with the leak, integrate, fire and refractory characteristics increasing the bio-fidelity of current skyrmion-based devices.
Nirenberg’s contributions to linear partial differential equations: Pseudo-differential operators and solvability
Authors: Dencker Nils
Published: February 2023

This article is a survey of Louis Nirenberg’s contributions to linear partial differential equations, focusing on his groundbreaking work on pseudo-differential operators and solvability.
The Oxford Encyclopedia of Environmental Economics
Authors: Kahn James R.
Published: February 2023

Environmental economics is an increasingly important area of research, though is often misunderstood by natural scientists, policymakers, and neoclassical economists alike. The Oxford Encyclopedia of Environmental Economics aims to bridge this gap, offering an expansive overview of the field’s key concepts, practical applications, and interdisciplinary perspectives from a set of diverse and authoritative authors. Major themes of the collection include environmental regulation, valuation, sustainability, natural resources, impacts on risk and human health, among others. Articles introduce readers to the topic at an accessible level while also being of interest to high level scholars in environmental economics and related fields seeking greater understanding of the subject.
Facilitators and barriers to implementing an acute geriatric community hospital in the Netherlands: a qualitative study
Authors: Ribbink Marthe E , de Vries-Mols Wieteke C B M , MacNeil Vroomen Janet L , Franssen Remco , Resodikromo Melissa N , Buurman Bianca M ,   the AGCH study group, Struan F A , van den Broek R H A , Frenkel W J , Henstra M J , Kaland K J , Koelé M , van Maanen M A , Melkert C J M , Parlevliet J L , van Poelgeest E P , Potgieter E , Oudejans I , Smorenberg A , van Rijn P M A , van der Velde N , van der Woude S , Willems H C , Wyatt D
Published: February 2023

Background

there is a trend across Europe to enable more care at the community level. The Acute Geriatric Community Hospital (AGCH) in the Netherlands in an acute geriatric unit situated in a skilled nursing facility (SNF). It provides hospital-level care for older adults with acute medical conditions. The aim of this study is to identify barriers and facilitators associated with implementing the AGCH in a SNF.

Methods

semi-structured interviews (n = 42) were carried out with clinical and administrative personnel at the AGCH and university hospital and stakeholders from the partnering care organisations and health insurance company. Data were analysed using thematic analysis.

Results

facilitators to implementing the AGCH concept were enthusiasm for the AGCH concept, organising preparatory sessions, starting with low-complex patients, good team leadership and ongoing education of the AGCH team. Other facilitators included strong collaboration between stakeholders, commitment to shared investment costs and involvement of regulators.

Barriers to implementation were providing hospital care in an SNF, financing AGCH care, difficulties selecting patients at the emergency department, lack of protocols and guidelines, electronic health records unsuited for hospital care, department layout on two different floors and complex shared business operations. Furthermore, transfer of acute care to the community care meant that some care was not reimbursed.

Conclusions

the AGCH concept was valued by all stakeholders. The main facilitators included the perceived value of the AGCH concept and enthusiasm of stakeholders. Structural financing is an obstacle to the expansion and continuation of this care model.
Genetically downregulated Interleukin-6 signalling is associated with a lower risk of frailty
Authors: Mourtzi Niki , Georgakis Marios K , Ntanasi Eva , Hatzimanolis Alexandros , Ramirez Alfredo , Heilmann-Heimbach Stephanie , Grenier-Boley Benjamin , Lambert Jean-Charles , Yannakoulia Mary , Kosmidis Mary , Dardiotis Efthimios , Hadjigeorgiou Giorgos , Sakka Paraskevi , Scarmeas Nikolaos
Published: February 2023

Background

numerous studies point towards a critical role of Interleukin 6 (IL-6) pathway in frailty pathogenesis yet the causal relationship between the two remains elusive.

Methods

we selected genetic variants near the IL-6 receptor locus (IL-6R) associated with reduced C-reactive protein (CRP) levels, a downstream effector of IL-6 pathway, and we used them as genetic proxies of IL-6 signalling downregulation. We then performed a two-sample Mendelian randomisation (MR) to investigate the association with frailty status, as defined by the Frailty Index (FI) in 11,171 individuals from the Hellenic Longitudinal Investigation of Ageing and Diet (HELIAD) study. MR analysis was repeated after excluding depression or cognition-related FI items as well as following age or sex stratification. Association with frailty was also examined using an alternative instrument, weighted on s-IL-6R levels. Replication was attempted in UK Biobank dataset.

Results

genetic predisposition to IL-6 signalling downregulation, weighted on CRP levels, was associated with lower risk of frailty, inserted either as categorical (odds ratio [95% confidence interval] = 0.15 [−3.39, −0.40], P = 0.013) or continuous variable (beta [se] = −0.09 [0.003], P = 0.0009). Sensitivity analyses revealed similar estimates across different MR methods with no evidence for horizontal pleiotropy or heterogeneity. Results remained robust after exclusion of depression or cognition-related FI items and following sex or age stratification. Genetically increased s-IL-6R levels were negatively correlated with frailty and this finding remained significant in a meta-analysis of UK Biobank and HELIAD cohorts.

Conclusion

our results support a potential causal effect of IL-6 signalling on frailty and further suggest that downregulation of IL-6 levels may reduce frailty risk.
Epistatic interactions among multiple copies of FLC genes with naturally occurring insertions correlate with flowering time variation in radish
Authors: Mitsui Yuki , Yokoyama Hinano , Nakaegawa Wataru , Tanaka Keisuke , Komatsu Kenji , Koizuka Nobuya , Okuzaki Ayako , Matsumoto Takashi , Takahara Manabu , Tabei Yutaka
Published: February 2023

Brassicaceae crops, which underwent whole-genome triplication during their evolution, have multiple copies of flowering-related genes. Interactions among multiple gene copies may be involved in flowering time regulation; however, this mechanism is poorly understood. In this study, we performed comprehensive, high-throughput RNA sequencing analysis to identify candidate genes involved in the extremely late-bolting (LB) trait in radish. Then, we examined the regulatory roles and interactions of radish FLOWERING LOCUS C (RsFLC) paralogs, the main flowering repressor candidates. Seven flowering integrator genes, five vernalization genes, nine photoperiodic/circadian clock genes and eight genes from other flowering pathways were differentially expressed in the early-bolting (EB) cultivar ‘Aokubinagafuto’ and LB radish cultivar ‘Tokinashi’ under different vernalization conditions. In the LB cultivar, RsFLC1 and RsFLC2 expression levels were maintained after 40 days of cold exposure. Bolting time was significantly correlated with the expression rates of RsFLC1 and RsFLC2. Using the EB × LB F2 population, we performed association analyses of genotypes with or without 1910- and 1627-bp insertions in the first introns of RsFLC1 and RsFLC2, respectively. The insertion alleles prevented the repression of their respective FLC genes under cold conditions. Interestingly, genotypes homozygous for RsFLC2 insertion alleles maintained high RsFLC1 and RsFLC3 expression levels under cold conditions, and two-way analysis of variance revealed that RsFLC1 and RsFLC3 expression was influenced by the RsFLC2 genotype. Our results indicate that insertions in the first introns of RsFLC1 and RsFLC2 contribute to the late-flowering trait in radish via different mechanisms. The RsFLC2 insertion allele conferred a strong delay in bolting by inhibiting the repression of all three RsFLC genes, suggesting that radish flowering time is determined by epistatic interactions among multiple FLC gene copies.
An immune-suppressing protein in human endogenous retroviruses
Authors: Zhang Huan , Ni Shengliang , Frith Martin C
Published: February 2023

Motivation

Retroviruses are important contributors to disease and evolution in vertebrates. Sometimes, retrovirus DNA is heritably inserted in a vertebrate genome: an endogenous retrovirus (ERV). Vertebrate genomes have many such virus-derived fragments, usually with mutations disabling their original functions.

Results

Some primate ERVs appear to encode an overlooked protein. This protein is homologous to protein MC132 from Molluscum contagiosum virus, which is a human poxvirus, not a retrovirus. MC132 suppresses the immune system by targeting NF-κB, and it had no known homologs until now. The ERV homologs of MC132 in the human genome are mostly disrupted by mutations, but there is an intact copy on chromosome 4. We found homologs of MC132 in ERVs of apes, monkeys and bushbaby, but not tarsiers, lemurs or non-primates. This suggests that some primate retroviruses had, or have, an extra immune-suppressing protein, which underwent horizontal genetic transfer between unrelated viruses.

Contact

mcfrith@edu.k.u-tokyo.ac.jp
scBGEDA: deep single-cell clustering analysis via a dual denoising autoencoder with bipartite graph ensemble clustering
Authors: Wang Yunhe , Yu Zhuohan , Li Shaochuan , Bian Chuang , Liang Yanchun , Wong Ka-Chun , Li Xiangtao
Published: February 2023

Motivation

Single-cell RNA sequencing (scRNA-seq) is an increasingly popular technique for transcriptomic analysis of gene expression at the single-cell level. Cell-type clustering is the first crucial task in the analysis of scRNA-seq data that facilitates accurate identification of cell types and the study of the characteristics of their transcripts. Recently, several computational models based on a deep autoencoder and the ensemble clustering have been developed to analyze scRNA-seq data. However, current deep autoencoders are not sufficient to learn the latent representations of scRNA-seq data, and obtaining consensus partitions from these feature representations remains under-explored.

Results

To address this challenge, we propose a single-cell deep clustering model via a dual denoising autoencoder with bipartite graph ensemble clustering called scBGEDA, to identify specific cell populations in single-cell transcriptome profiles. First, a single-cell dual denoising autoencoder network is proposed to project the data into a compressed low-dimensional space and that can learn feature representation via explicit modeling of synergistic optimization of the zero-inflated negative binomial reconstruction loss and denoising reconstruction loss. Then, a bipartite graph ensemble clustering algorithm is designed to exploit the relationships between cells and the learned latent embedded space by means of a graph-based consensus function. Multiple comparison experiments were conducted on 20 scRNA-seq datasets from different sequencing platforms using a variety of clustering metrics. The experimental results indicated that scBGEDA outperforms other state-of-the-art methods on these datasets, and also demonstrated its scalability to large-scale scRNA-seq datasets. Moreover, scBGEDA was able to identify cell-type specific marker genes and provide functional genomic analysis by quantifying the influence of genes on cell clusters, bringing new insights into identifying cell types and characterizing the scRNA-seq data from different perspectives.

Availability and implementation

The source code of scBGEDA is available at https://github.com/wangyh082/scBGEDA. The software and the supporting data can be downloaded from https://figshare.com/articles/software/scBGEDA/19657911.

Supplementary information

Supplementary data are available at Bioinformatics online.
Measuring the Quality of Statutory Social Workers’ Communication Skills with Young People: Reliability of the My Social Work Partner Scales
Authors: Baviskar Siddhartha , Antczak Helle B , Bjerregaard Anne H , Ebsen Frank C , Larsen Karin S , Mackrill Thomas , Rosted Malene K , Steensbæk Signe
Published: February 2023

Statutory meetings are at the core of social work practice, yet there is no quantitatively tested common set of criteria for assessing statutory social workers’ communication skills with young people. Reliably measuring such skills is important for the training and supervision of social workers as well for drawing conclusions about whether such skills impact service users’ outcomes. To fill this gap, we developed a new measure, the My Social Work Partner (MRP in Danish abbreviation) scales, which measure eleven dimensions of statutory communication. We tested the inter-coder reliability and intra-coder reliability of codings on the MRP scales using the intra-class correlation coefficient (ICC) in a random sample of thirty videotapes of statutory meetings. Five professional social workers participated in the inter-coder reliability test; three of them coded the same films again after a three- to five-month interval for the intra-coder reliability test. ICC estimates of inter-coder reliability ranged from good to excellent. Intra-coder reliability estimates ranged from fair to excellent. Overall, the results are promising and support the use of the MRP scales in social work practice with young persons, education and research. Future research will focus on how to improve the intra-coder reliability of the scales, in particular the Dialogue structure scale.