bluuebunny/crossref_metadata_2025 huggingface dataset:
Antigenic mapping of the hemagglutinin of the H9 subtype influenza A viruses using sera from Japanese quail (
Coturnix c. japonica
)
Authors: Carnaccini Silvia , Cáceres C. Joaquín , Gay L. Claire , Ferreri Lucas M. , Skepner Eugene , Burke David F. , Brown Ian H. , Geiger Ginger , Obadan Adebimpe , Rajao Daniela S. , Lewis Nicola S. , Perez Daniel R.
Published: October 2023

Influenza A viruses (FLUAV) of the H9N2 subtype are zoonotic pathogens that cause significant economic damage to the poultry industry. Vaccination to prevent and control H9N2 infections in poultry is widely employed in the Middle East and Asia. We used phylogenetics and antigenic analysis to study the antigenic properties of the H9 hemagglutinin (HA) using sera produced in Japanese quail (
Coturnix c. japonica
). Consensus HA1 sequences were generated to capture antigenic diversity among isolates. We constructed chimeric H9N2 viruses containing the HA1 of each consensus sequence on a constant isogenic backbone. The resulting viruses were used to generate antisera from quail, a common and significant minor poultry species whose anti-HA response profiles remain poorly defined. Antigenic maps were generated by plotting the cross-hemagglutination inhibition (HI) data from the panel of quail sera against the chimeric constructs and 51 H9 field isolates. The chimeric antigens were divided into four different antigenic profiles (cyan, blue, orange, and red). Site-directed mutagenesis analysis showed nine amino acid positions of antigenic relevance. Substitutions at amino acid positions 149, 150, and 180 (H9 HA numbering) had relatively significant impact on HI activity using quail sera. Substitutions E180A and R131K/E180A led to the most significant antigenic change transitions. This study provides insights into the antigenic profile of H9 FLUAVs, with important implications for understanding antigenic drift and improving vaccine development for use in minor poultry species.

IMPORTANCE

Determining the relevant amino acids involved in antigenic drift on the surface protein hemagglutinin (HA) is critical to understand influenza virus evolution and efficient assessment of vaccine strains relative to current circulating strains. We used antigenic cartography to generate an antigenic map of the H9 hemagglutinin (HA) using sera produced in one of the most relevant minor poultry species, Japanese quail. Key antigenic positions were identified and tested to confirm their impact on the antigenic profile. This work provides a better understanding of the antigenic diversity of the H9 HA as it relates to reactivity to quail sera and will facilitate a rational approach for selecting more efficacious vaccines against poultry-origin H9 influenza viruses in minor poultry species.
Gain without pain: adaptation and increased virulence of Zika virus in vertebrate host without fitness cost in mosquito vector
Authors: Jaeger Anna S. , Marano Jeffrey , Riemersma Kasen K. , Castaneda David , Pritchard Elise M. , Pritchard Julia C. , Bohm Ellie K. , Baczenas John J. , O'Connor Shelby L. , Weger-Lucarelli James , Friedrich Thomas C. , Aliota Matthew T.
Published: October 2023

Zika virus (ZIKV) is now in a post-pandemic period, for which the potential for re-emergence and future spread is unknown. Adding to this uncertainty is the unique capacity of ZIKV to directly transmit between humans via sexual transmission. Recently, we demonstrated that direct transmission of ZIKV between vertebrate hosts leads to rapid adaptation resulting in enhanced virulence in mice and the emergence of three amino acid substitutions (NS2A-A117V, NS2A-A117T, and NS4A-E19G) shared among all vertebrate-passaged lineages. Here, we further characterized these host-adapted viruses and found that vertebrate-passaged viruses do not lose fitness or transmission potential in mosquitoes. To understand the contribution of genetic changes to the enhanced virulence and transmission phenotype, we engineered these amino acid substitutions, singly and in combination, into a ZIKV infectious clone. We found that NS4A-E19G contributed to the enhanced virulence and mortality phenotype in mice. Further analyses revealed that NS4A-E19G results in increased viral loads and distinct transcriptional patterns for innate immune genes in the brain. None of the substitutions contributed to changes in mosquito vector competence. Together, these findings suggest that direct transmission chains could enable the emergence of more virulent ZIKV strains without compromising mosquito transmission capacity, although the underlying genetics of these adaptations are complex.

IMPORTANCE

Previously, we modeled direct transmission chains of Zika virus (ZIKV) by serially passaging ZIKV in mice and mosquitoes and found that direct mouse transmission chains selected for viruses with increased virulence in mice and the acquisition of non-synonymous amino acid substitutions. Here, we show that these same mouse-passaged viruses also maintain fitness and transmission capacity in mosquitoes. We used infectious clone-derived viruses to demonstrate that the substitution in nonstructural protein 4A contributes to increased virulence in mice.
Evolutionary and spatiotemporal analyses reveal multiple introductions and cryptic transmission of SARS-CoV-2 VOC/VOI in Malta
Authors: Trovao Nidia S. , Pan Vincent , Goel Chirag , Gallego-García Pilar , Liu Yunxi , Barbara Christopher , Borg Rebecca , Briffa Mark , Cilia Chanelle , Grech Laura , Vassallo Mario , Treangen Todd J. , Posada David , Beheshti Afshin , Borg Joseph , Zahra Graziella
Published: October 2023

Genomic surveillance and epidemiology have shed light on the viral diversity driving coronavirus disease 2019 (COVID-19) outbreaks and are important during waves of highly transmissible and immune-escaping variants of interest or of concern (VOCs). We analyzed the epidemiological data of the understudied country of Malta and related the patterns observed with viral genetic sequences obtained through the surveillance system headed by the Mater Dei Hospital and the University of Malta. We reconstructed the evolutionary history and spatiotemporal dynamics of Maltese severe acute respiratory syndrome coronavirus 2 viruses using a phylodynamics framework. Our findings suggest that the number of cases associated with B.1.1.7/Alpha, B.1.617.2.X/Delta, and B.1.1.529.X/Omicron VOCs was nine times higher than those associated with wild-type variants. The positivity rates in Malta remained low to moderate (<10%). A combination of public health interventions appeared to have allowed Malta to mitigate the impact of COVID-19. Our phylodynamic reconstruction traced most of the 173 viral introductions inferred to countries in Northern Europe, which is consistent with flight connectivity patterns. We also observed prolonged periods of cryptic transmission (median = 102 days) until expansion into larger outbreaks. These larger outbreaks were more easily detected by the intermittent genomic surveillance in Malta, characterized by periods of sequencing hiatus. Our study demonstrates that integrating epidemiological and genomic data are crucial for uncovering the COVID-19 dynamics of understudied locations, particularly when genomic surveillance is suboptimal. Accordingly, strengthening the genomic surveillance system in Malta should help in the earlier detection of introductions and minimize viral expansion in the country while informing public health interventions.

IMPORTANCE

Our study provides insights into the evolution of the coronavirus disease 2019 (COVID-19) pandemic in Malta, a highly connected and understudied country. We combined epidemiological and phylodynamic analyses to analyze trends in the number of new cases, deaths, tests, positivity rates, and evolutionary and dispersal patterns from August 2020 to January 2022. Our reconstructions inferred 173 independent severe acute respiratory syndrome coronavirus 2 introductions into Malta from various global regions. Our study demonstrates that characterizing epidemiological trends coupled with phylodynamic modeling can inform the implementation of public health interventions to help control COVID-19 transmission in the community.
New insights into the pathogenesis and transmission of
Brucella pinnipedialis
: systemic infection in two bottlenose dolphins (
Tursiops truncatus
)
Authors: Vargas-Castro Ignacio , Crespo-Picazo José Luis , Fayos Manena , Jiménez-Martínez María de los Ángeles , Torre-Fuentes Laura , Álvarez Julio , Moura André E. , Hernández Marta , Buendía Aranzazu , Barroso-Arévalo Sandra , García-Seco Teresa , Pérez-Sancho Marta , De Miguel María Jesús , Andrés-Barranco Sara , Marco-Cabedo Vicente , Peñin-Villahoz Gaizka , Muñoz Pilar María , Domínguez Lucas , García-Párraga Daniel , Sánchez-Vizcaíno José Manuel
Published: October 2023

The emergence of
Brucella
infections in marine mammals is a growing concern. The present study reports two cases of systemic
Brucella pinnipedialis
infection detected in bottlenose dolphins (
Tursiops truncatus
) pair stranded together in the Cantabrian coast of Spain. Both animals showed systemic lesions associated with the
Brucella
infection, more severe in the younger dolphin, considered the likely offspring of the other individual. Real-time PCR, bacterial culture, and whole-genome sequencing were used to detect and characterize the
Brucella
strains involved in both dolphins. The phylogenetic analysis performed on the
Brucella
genomes retrieved revealed that the species involved was
B. pinnipedialis
(ST25). Both animals resulted seropositive in a commercial multispecies blocking ELISA but tested negative in the standard Rose Bengal test. To the best of our knowledge, this is the first report of a systemic infection resulting in various lesions associated with
Brucella pinnipedialis
(ST25) in two bottlenose dolphins. It is also the initial isolation of
Brucella
in the milk of a non-pregnant or non-aborting female cetacean likely stranded with its offspring. These findings provide new insights into the epidemiology and clinical impact of
B. pinnipedialis
infection in cetaceans and underscore the importance of continued diagnostic surveillance to gain better understanding of brucellosis effects and transmission in marine mammal populations.

IMPORTANCE

Brucella
spp. are zoonotic pathogens that can affect both terrestrial and marine mammals.
Brucella ceti
has been identified in various cetacean species, but only one sequence type (ST27) has been reported in humans. However, it is important to conduct surveillance studies to better understand the impact of marine
Brucella
species on marine mammals, a typically understudied host group. Here, we describe a systemic infection by two related strains of
Brucella pinnipedialis
(ST25) in a couple of live-stranded bottlenose dolphins, with more severe lesions in the younger animal. Furthermore,
B. pinnipedialis
was first detected in milk from a female cetacean that stranded with its offspring. Our study reveals novel insights into the epidemiology and pathological consequences of
B. pinnipedialis
infections in cetaceans, emphasizing the crucial importance of ongoing surveillance and accurate diagnosis to understand the impact of this pathogen on marine mammal populations.
Another tick bites the dust: exploring the association of microbial composition with a broad transmission competence of tick vector species
Authors: Mota Tiago F. , Fukutani Eduardo R. , Martins Kelsilandia A. , Salgado Vanessa R. , Andrade Bruno B. , Fraga Deborah B. M. , Queiroz Artur T. L.
Published: October 2023

Ticks harbor and transmit many different pathogens. While some species are competent vectors of a single pathogen, mono-competent vectors (MCV), other species are proven to be competent vectors of several pathogens, pluri-competent vectors (PCV). Such a difference in vector competence might be related to the microbiome. To better comprehend its influence on the vector competence of ticks for one or several pathogens, a data-driven approach using publicly available databases was applied on bacterial 16S rRNA from MCV and PCV tick species. Alpha and beta diversity, co-occurrence networks, and functional profiles were analyzed. A differential analysis was performed to identify bacterial genera associated with PCV ticks. These tick species presented higher richness, and the bacterial composition showed a significant difference between MCV and PCV ticks. The bacteria genera of PCV ticks demonstrated fewer correlations within each other in comparison with MCV ticks. The differential analysis revealed 14 bacteria genera related to PCV tick species, such as
Rickettsia
,
Staphylococcus
, and
Corynebacterium
. Using 24 differently abundant genera, tick samples from another data set could be classified into either PCV or MCV with high accuracy and concordance. Moreover, pathway regulation related to reactive oxygen species detoxification, β-Lactam resistance, and dTDP-L-rhamnose biosynthesis could be participating in the competence of PCV ticks for several tick-borne pathogens. These findings enlighten our understanding of the bacteria community’s role on some tick species’ broad vector competence.

IMPORTANCE

Some tick species are competent to transmit more than one pathogen while other species are, until now, known to be competent to transmit only one single or any pathogen. Such a difference in vector competence for one or more pathogens might be related to the microbiome, and understanding what differentiates these two groups of ticks could help us control several diseases aiming at the bacteria groups that contribute to such a broad vector competence. Using 16S rRNA from tick species that could be classified into these groups, genera such as Rickettsia and Staphylococcus seemed to be associated with such a broad vector competence. Our results highlight differences in tick species when they are divided based on the number of pathogens they are competent to transmit. These findings are the first step into understanding the relationship between one single tick species and the pathogens it transmits.
Air Composition over the Russian Arctic: 1—Methane
Authors: Antokhina O. Yu. , Antokhin P. N. , Arshinova V. G. , Arshinov M. Yu. , Belan B. D. , Belan S. B. , Guruleva E. V. , Davydov D. K. , Ivlev G. A. , Kozlov A. V. , Law K. , Rasskazchikova T. M. , Paris J.-D. , Savkin D. E. , Simonenkov D. V. , Sklyadneva T. K. , Tolmachev G. N. , Fofonov A. V.
Published: October 2023

In the Arctic, global warming is 2–3 times faster than over other regions of the globe. As a result, noticeable changes are already being recorded in all areas of the environment. However, there is very little data on such changes in the Russian Arctic. Therefore, to fill the gap in the data on the vertical distribution of the gas and aerosol composition of air in this region, an experiment was carried out on the Tu-134 Optik flying laboratory in September 2020 to sound the atmosphere and water surface over the water areas of all seas in the Russian Arctic. This paper analyzes the spatial distribution of methane. It is shown that during the experiment its concentration was the highest over the Kara Sea (2090 ppb) and the lowest over the Chukchi Sea (2005 ppb). The East Siberian and Bering Seas were slightly different from the Chukchi Sea in terms of the methane concentration. Average values of CH4 are characteristic of the Barents (2030 ppb) and the Laptev Seas (2040 ppb). The difference between the concentrations at an altitude of 200 meters and in the free troposphere attained 150 ppb over the Kara Sea, decreased to 91 and 94 ppb over the Barents and Laptev Seas, and further decreased over the East Siberian, Chukchi, and Bering Seas to 66, 63, and 74 ppb, respectively. Horizontal heterogeneity in the distribution of methane over the Arctic seas is the greatest over the Laptev Sea, where it attained 73 ppb. It is two times higher than over the Barents and Kara Seas, and 5–7 times higher than over the East Siberian and Bering Seas.
Deeply virtual compton scattering at future electron-ion colliders
Authors: Xie Gang , Kou Wei , Fu Qiang , Ye Zhenyu , Chen Xurong
Published: October 2023

The study of hadronic structure has been carried out for many years. Generalized parton distribution functions (GPDs) provide broad information on the internal structure of hadrons. Combining GPDs and high-energy scattering experiments, we expect yielding three-dimensional physical quantities from experiments. The Deeply Virtual Compton Scattering (DVCS) process is a powerful tool for studying GPDs. It is one of the important experiments of Electron Ion Collider (EIC) and Electron ion collider at China (EicC) in the future. In the initial stage, the proposed EicC will have polarized electrons with energies of $$3 \sim 5$$

3
∼
5

 GeV colliding with polarized protons with energies of $$12 \sim 25$$

12
∼
25

 GeV, with luminosity up to $$1 \sim 2 \times 10^{33}$$

1
∼
2
×

10
33

 cm$$^{-2}$$

-
2

 s$$^{-1}$$

-
1

. EIC, which will be constructed in the coming years, will cover center-of-mass energies ranging from 30 to 50 GeV, with a luminosity of about $$10^{33} \sim 10^{34}$$

10
33

∼

10
34

 cm$$^{-2}$$

-
2

 s$$^{-1}$$

-
1

. In this work, we present a detailed simulation of DVCS to study the feasibility of experiments at EicC and EIC. Referring the method used by HERMES Collaboration, and comparing the model calculations with pseudo data of asymmetries attributed to the DVCS, we obtained a model-dependent constraint on the total angular momentum of up and down quarks in the proton.
Performance of high impedance resonators in dirty dielectric environments
Authors: Ungerer J. H. , Sarmah D. , Kononov A. , Ridderbos J. , Haller R. , Cheung L. Y. , Schönenberger C.
Published: October 2023

High-impedance resonators are a promising contender for realizing long-distance entangling gates between spin qubits. Often, the fabrication of spin qubits relies on the use of gate dielectrics which are detrimental to the quality of the resonator. Here, we investigate loss mechanisms of high-impedance NbTiN resonators in the vicinity of thermally grown SiO2 and Al2O3 fabricated by atomic layer deposition. We benchmark the resonator performance in elevated magnetic fields and at elevated temperatures and find that the internal quality factors are limited by the coupling between the resonator and two-level systems of the employed oxides. Nonetheless, the internal quality factors of high-impedance resonators exceed 103 in all investigated oxide configurations which implies that the dielectric configuration would not limit the performance of resonators integrated in a spin-qubit device. Because these oxides are commonly used for spin qubit device fabrication, our results allow for straightforward integration of high-impedance resonators into spin-based quantum processors. Hence, these experiments pave the way for large-scale, spin-based quantum computers.
Classification of pairing phase transition in the hot nucleus
Authors: Gao Yuhang , Lin Yanlong , Liu Lang
Published: October 2023

The hot nucleus [Formula: see text] is investigated using covariant density functional theory, where the shell-model-like approach treats the pairing correlation. Lee–Yang’s theorem is applied to classify the pairing phase transition by analyzing the distribution of zeros of the partition function in the complex temperature plane. The distribution of zeros of the partition function converges with increasing particle numbers and illustrates the characteristics of the phase transition. In our calculations, we determine the first-order of the phase transition near the critical temperature. Different seniority states show the pairing phase transition from a superfluid to a normal phase, ranging from fully paired states to completely unpaired states.
INFLUENCE OF ARGON IRRADIATION ON ELECTRICAL PROPERTIES OF PVA/NaI POLYMER COMPOSITES
Authors: ATTA A. , ALOTAIBI B. M. , WALY S. A. , REHEEM A. M. ABDEL , AL-YOUSEF HAIFA A.
Published: October 2023

In this work, PVA/NaI consisting of polyvinyl alcohol (PVA) and sodium iodine (NaI) is irradiated using argon at fluence (45×10[Formula: see text], 90×10[Formula: see text], and 135×10[Formula: see text] ion/cm2). The structure is investigated by XRD technique. The influence of argon ion is studied theoretically by SRIM/TRIM simulations. The target vacancies are recorded 46/ion, target displacements are 47/ion, and the replacements atoms are 1/ion. Also, the dielectric properties were determined in the frequency of 100 Hz to 5 MHz. With an average fluence 90×10[Formula: see text] ions/cm2, electrical conductivity and dielectric constants have increased to twice their initial value. Additionally, after being exposed to an ion beam, the dielectric loss is reduced to around half of its original value. For both the control and irradiation samples, the attenuation and half layers were estimated. The dielectric characteristics of the irradiated samples were found to improve. Numerous uses, including energy storage and batteries, are rendered possible by these results.
FLUID CHARACTERISTICS AND POLISHING EXPERIMENT OF INCLINED HOLE ARRAY USING ABRASIVE WATER FLOW
Authors: XIAO LIJUN , TANG YANGYANG , LIU ZHUANG , GAO CHANGSHUI , SHENG CHAO
Published: October 2023

Inclined hole arrays on superalloys have important applications in aeroengines. However, defects occur during fabrication of inclined holes using thermal drilling methods, i.e. electrical discharge drilling (EDD), including a recast layer and microcracks on the hole wall. Therefore, abrasive water flow polishing (AWFP) of a superalloy inclined hole array machined via EDD was investigated in this study. Two types of specimens were designed: a hole array of identical size and a hole array with an identical inclination angle. The fluid simulation revealed that the fluid velocity and pressure on the lower edge of the inclined hole were significantly higher than those on the upper edge when the fluid flowed forward. The fluid characteristics exhibited opposite trends when backward flow was implemented. Time-division bidirectional flow can effectively compensate for flow field nonuniformity and improve material removal consistency during polishing. The experimental results show that for inclined holes with identical inclination angles, the size expansion decreases with an increase in the hole diameter owing to the lower fluid velocity and material removal volume in the relatively larger holes. Consequently, surface roughness Ra increases with hole size. For inclined holes with identical diameters, the size expansions of the entrance and exit approach the same level; whereas, Ra decreased with an increase in the inclination angle. The hole taper slightly reduced in all cases. Using garnet abrasives with 1300 mesh size, 1.5 wt.% abrasive concentration, and 3 MPa fluid pressure, the surface roughness Ra of target holes was reduced from pre-polishing [Formula: see text] 5.0 [Formula: see text]m to approximately post-polishing 1.0 [Formula: see text]m. The recast layer on the hole wall caused by EDD was completely removed.
FURTHER IMPROVING THE MECHANICAL AND HIGH-TEMPERATURE TRIBOLOGICAL PROPERTIES OF SILICON-DOPED DIAMOND-LIKE CARBON FILM BY TUNGSTEN INCORPORATION
Authors: YU WEIJIE , HUANG WEIJIU , WANG JUNJUN , SU YONGYAO , GONG XIAOHONG
Published: October 2023

As an excellent solid lubrication material, the poor high-temperature tribological properties of diamond-like carbon (DLC) films severely limit their applications. In this study, tungsten (W) was incorporated into Si-doped DLC films fabricated via reactive magnetron sputtering. The effect of the W content ranging from 0 to 13.12 at.% on the film structure, bonding states, mechanical and high-temperature tribological properties of Si and W co-doped DLC (Si–W-DLC) films has been investigated. The results show that a small amount of tungsten incorporation (4.45 at.%, Si–[Formula: see text]-DLC) increases the mechanical properties of the Si–[Formula: see text]-DLC film without a significant decrease in the fraction of sp3 content. The incorporation of 4.45 at.% W improves the wear resistance and stabilizes the friction coefficient curves at temperatures up to [Formula: see text]C. The high residual stress caused by the highly distorted C–W bond and the low friction coefficient attributed to the formation of WO3 on the sliding surface should be responsible for the excellent tribological performance of the Si–[Formula: see text]-DLC film. It is believed that the Si and W co-doped DLC film can provide another strategy for expanding the high-temperature application of DLC films.
An infinite-dimensional nonlinear equation related to Gibbs measures of a SOS model
Authors: Rozikov U. A.
Published: October 2023

For the solid-on-solid (SOS) model with an external field and with spin values from the set of all integers on a Cayley tree, each (gradient) Gibbs measure corresponds to a boundary law (an infinite-dimensional vector function defined on vertices of the Cayley tree) satisfying a nonlinear functional equation. Recently some translation-invariant and height-periodic (non-normalizable) solutions to the equation are found. Here, our aim is to find non-height-periodic and non-normalizable boundary laws for the SOS model. By such a solution one can construct a non-probability Gibbs measure. We find explicitly several non-normalizable boundary laws. Moreover, we reduce the problem to solving of a nonlinear, second-order difference equation. We give analytic and numerical analyses of the difference equation.
Free-Vibration, Buckling, and Static Analysis of Sandwich Panels with a Square Honeycomb Core Using a Meshfree Method
Authors: Arabzadeh Amir , Sarrami Saeid , Azhari Mojtaba
Published: October 2023

Meshless methods are a relatively modern approach that has garnered significant interest in analyzing and investigating complex structural problems thanks to distinctive features such as high accuracy, flexibility, rapid calculation speed, and cost–effectiveness. In the present study, the element-free Galerkin method is employed as a meshless approach, wherein a set of arbitrary nodes is distributed across the problem’s geometry, including its boundaries, to define the problem domain. The Moving Least Squares approximation is also utilized to formulate the shape functions. Given the intricate geometry of the honeycomb core within sandwich panels, the study employs the generalized method to derive the effective mechanical properties of the honeycomb core. Furthermore, to acquire displacement fields and establish relationships for the problem, the classic plate theory and the first-order shear deformation theory are independently applied. These relationships are then formulated using the Galerkin meshless method. Finally, the obtained parameters are evaluated, and the validity of these relationships is confirmed by comparing the results of this study with those presented in existing articles. The outlined procedure has been systematically simulated through a step-by-step MATLAB program. Subsequently, the impact of different boundary conditions, individual layer thicknesses, dimension ratios, and core wall spacing on the panel’s displacement, free-vibration, and buckling behaviors is thoroughly investigated. The obtained results substantiate the efficacy of the utilized methodology, demonstrating a favorable combination of accuracy and convergence rate.
A Semi-Analytical Method to Design Distributed Dynamic Vibration Absorber of Beam Under General Elastic Edge Constraints
Authors: Du Yuan , Tang Yang , Pang Fuzhen , Ma Yong , Zou Yucheng
Published: October 2023

In engineering practice, dynamic vibration absorber is an effective method to control vibration of beam structure. The mathematical model of beam coupled with spring–mass systems under elastic edge constraints is established in this paper. In addition to Fourier cosine series, supplementary sine functions are introduced to represent the displacement function of the beam. The spring–mass system is considered by increasing degrees of freedom when constructing the mass matrix and stiffness matrix. The efficiency of solving equivalent mass is greatly improved in the comparison with FEM, which is important when designing dynamic vibration absorber. Subsequently, we conduct parametric analysis of the control effect about the dynamic vibration absorber based on the current mathematical model. The procedure of designing distributed dynamic vibration absorber of beam structure under various boundary condition is also presented. To verify the validity of the current mathematical model and design procedure, a cantilever beam experiment was conducted. The findings presented in the current research may be useful for researchers in the process of multi-line spectrum vibration control of beam structure.
A Higher-Order Shear Deformation Theory and Modified Couple Stress Theory for Size-Dependent Analysis of Porous Microbeams Resting on a Foundation
Authors: Nguyen Ngoc-Duong , Nguyen Thien-Nhan , Trinh Luan C. , Nguyen Trung-Kien
Published: October 2023

This paper presents a novel shear deformation theory for analyzing porous microbeams’ bending, buckling, and free vibration resting on a foundation. The proposed shear function incorporating three kinetic variables satisfies zero-traction boundary conditions on the top and bottom surfaces of the beams and does not require a shear correction factor. The modified couple stress theory accounts for the size-dependent effects, and the governing equations are derived from Lagrange’s equation using the proposed shear function. Legendre–Ritz functions are developed to analyze the porous microbeams’ buckling, free vibration, and bending behaviors. The effects of material length scale parameter, porosity, span-to-height ratio, boundary condition, and foundation parameter on the mechanical responses of beams are investigated. Numerical results demonstrate the accuracy and efficiency of the proposed theory and can serve as benchmarks for future analysis of porous microbeams on elastic foundations.
Torsional Buckling Analysis of Composite Anisogrid Conical Shells: Theoretical Approach and Numerical Validation
Authors: Shi Hougai , Fan Hualin
Published: October 2023

Torsional buckling analysis of composite anisogrid conical shells, with equiangular helical ribs, was investigated based on an equivalent variable stiffness continuum model. The buckling analysis is complicated by the variable geometry and stiffness of the lattice conical shell along the meridian. The smearing approach and the gradual function of the lattice cells were used to build the corresponding continuum model with varying stiffnesses. Recurrence relations were constructed from linearized buckling equations of the equivalent conical shell using the power series method and Fourier decomposition. The excellent precision and tremendous efficiency of the analytical solution was validated compared with numerical results through many design parameters of the lattice conical shell, such as the thickness of the ribs, the radius at the small end, and the height of the cone. Finally, a parametric analysis was used to discuss the influence of parameters on the critical buckling torsional moment. It is found that increasing rib thickness, end radius, the height of the cone, and strengthening boundary constraints can improve the critical buckling torsional moment.
Transient Attacks Against the VMG-KLJN Secure Key Exchanger
Authors: Ferdous Shahriar , Kish Laszlo B.
Published: October 2023

The security vulnerability of the Vadai, Mingesz, and Gingl (VMG) Kirchhoff–Law–Johnson–Noise (KLJN) key exchanger, as presented in the publication “Nature, Science Report 5 (2015) 13653”, has been exposed to transient attacks. Recently an effective defense protocol was introduced (Appl. Phys. Lett. 122 (2023) 143503) to counteract mean-square voltage-based (or mean-square current-based) transient attacks targeted at the ideal KLJN framework.

In this study, this same mitigation methodology has been employed to fortify the security of the VMG-KLJN key exchanger. It is worth noting that the protective measures need to be separately implemented for the HL and LH scenarios. This conceptual framework is corroborated through computer simulations, demonstrating that the application of this defensive technique substantially mitigates information leakage to a point of insignificance.
On the coercivity condition in the learning of interacting particle systems
Authors: Li Zhongyang , Lu Fei
Published: October 2023

In the inference for systems of interacting particles or agents, a coercivity condition ensures the identifiability of the interaction kernels, providing the foundation of learning. We prove the coercivity condition for stochastic systems with an arbitrary number of particles and a class of kernels such that the system of relative positions is ergodic. When the system of relative positions is stationary, we prove the coercivity condition by showing the strictly positive definiteness of an integral kernel arising in the learning. For the non-stationary case, we show that the coercivity condition holds when the time is large based on a perturbation argument.
An optimal estimate for linear reaction subdiffusion equations with Neumann boundary conditions
Authors: Cheng Xiujun , Xiong Wenzhuo , Wang Huiru
Published: October 2023

In this paper, we apply classical non-uniform L1 formula and the compact difference scheme for solving linear fractional systems with Neumann boundary conditions. A novelty and simple demonstration strategy is presented on the convergence analysis in the discrete maximum norm. Moreover, based on the special properties of the resulting coefficient matrix, diagonalization technique and discrete cosine transform (DCT) are adopted to speed up the convergence rate of the proposed method. In addition, the numerical scheme is also extended to the three-dimensional (3D) case. Several numerical experiments are given to support our findings.
On the limit distribution for stochastic differential equations driven by cylindrical non-symmetric α-stable Lévy processes
Authors: Li Ting , Fu Hongbo , Liu Xianming
Published: October 2023

This paper deals with the limit distribution for a stochastic differential equation driven by a non-symmetric cylindrical [Formula: see text]-stable process. Under suitable conditions, it is proved that the solution of this equation converges weakly to that of a stochastic differential equation driven by a Brownian motion in the Skorohod space as [Formula: see text]. Also, the rate of weak convergence, which depends on [Formula: see text], for the solution towards the solution of the limit equation is obtained. For illustration, the results are applied to a simple one-dimensional stochastic differential equation, which implies the rate of weak convergence is optimal.
One admissible critical pair without Lyapunov norm implies a tempered exponential dichotomy for Met-systems
Authors: Dragičević Davor , Zhang Weinian , Zhou Linfeng
Published: October 2023

It is known that a tempered exponential dichotomy (which is the version of nonuniform exponential dichotomy for random dynamical systems) can be described by admissibility of a pair of function classes defined in terms of Lyapunov norms. Moreover, for MET-systems (i.e. random dynamical systems which satisfy the assumptions of the Multiplicative Ergodic Theorem) over an ergodic base system, tempered exponential dichotomy can be described by admissibility of a pair of function spaces which are defined in terms of the original norm. In present paper, we find an admissibility description of tempered exponential dichotomies for MET-systems in terms of new output and input classes. These classes can be regarded as a critical case of admissibility classes in the known result. Finally, we use our new pair of admissible spaces to prove the roughness of tempered exponential dichotomies for parametric MET-systems and give a Hölder continuous dependence of the associated projections on the parameter.
A topological property of a hypergraph assigned to commutative rings
Authors: Selvakumar K. , Beautlin Jemi J. , Moniri Hamzekolaee A. R.
Published: October 2023

Studying algebraic structures via graphs and hypergraphs assigned to them can be of interest. Especially, computing the genus of a graph as a topological index leads to a better understanding of the related algebraic structure. In this direction we apply a hypergraph, namely [Formula: see text]-zero divisor hypergraph assigned to a commutative ring and study its genus. In this paper, we characterize all finite commutative nonlocal rings [Formula: see text] with identity whose [Formula: see text] has genus two. Further, we classify all finite commutative nonlocal rings [Formula: see text] whose [Formula: see text] has crosscap two. Moreover, we provide a MATLAB code for calculating [Formula: see text]-zero-divisor of [Formula: see text] and the hyperedge of [Formula: see text]-zero-divisor hypergraph of [Formula: see text].
Matching Rota–Baxter modules and matching 𝒪-operators of associative algebras
Authors: Zheng Huihui , Liu Linlin
Published: October 2023

In this paper, firstly, we introduce the notion of matching Rota–Baxter modules, which generalizes the notions of matching Rota–Baxter algebras and Rota–Baxter modules, and give its characteristic and construction. Secondly, we give the relation between matching Rota–Baxter modules and other modules structure. Finally, we introduce the notion of matching [Formula: see text]-operators of associative algebras which also generalizes the notion of matching Rota–Baxter algebras and give the solution of polarized associative Yang–Baxter equation by using the matching [Formula: see text]-operators of associative algebras. In addition, we introduce the definitions of the compatible matching [Formula: see text]-operators of associative algebras, matching Nijenhui operators, and compatible matching dendriform algebras, and consider their connection.
Automorphisms of Veronese subalgebras of polynomial algebras and free Poisson algebras
Authors: Aitzhanova Bakhyt , Makar-Limanov Leonid , Umirbaev Ualbai
Published: October 2023

The Veronese subalgebra [Formula: see text] of degree [Formula: see text] of the polynomial algebra [Formula: see text] over a field [Formula: see text] in the variables [Formula: see text] is the subalgebra of [Formula: see text] generated by all monomials of degree [Formula: see text] and the Veronese subalgebra [Formula: see text] of degree [Formula: see text] of the free Poisson algebra [Formula: see text] is the subalgebra spanned by all homogeneous elements of degree [Formula: see text], where [Formula: see text].

If [Formula: see text] then every derivation and every locally nilpotent derivation of [Formula: see text] and [Formula: see text] over a field [Formula: see text] of characteristic zero is induced by a derivation and a locally nilpotent derivation of [Formula: see text] and [Formula: see text], respectively. Moreover, we prove that every automorphism of [Formula: see text] and [Formula: see text] over a field [Formula: see text] closed with respect to taking all [Formula: see text]-roots of elements is induced by an automorphism of [Formula: see text] and [Formula: see text], respectively.
Change Agents’ Required Expertise to Implement an Educational Technology: A Mixed-Method Study
Authors: Jordahn Quentin , Da Dalto Laurent , Cabon Philippe
Published: October 2023

To support trainers in implementing emerging educational technologies into their practices, training centers nominate one or several change agents. The aim of this study is to identify their individual human factors in this organizational change process. Twenty-one experts in organizational change, training, and educational technology participated in this study that combined semi-structured interviews with two job analysis questionnaires. The data were first treated separately with descriptive statistics and directed content analysis. They were then analyzed jointly with a factorial correspondence analysis completed with a hierarchical ascending classification. Results highlight the core activity of a project manager and eight additional activities with their own individual human factors. They provide to the change agents’ team benefits, such as management, strategy, communication, training, analysis, facilitation, and technological, pedagogical, and financial expertise. Those findings suggest a protean activity of the change agent, hardly manageable by a single person, which practitioners should anticipate when managing change. This research also proposes an original method to obtain a deeper understanding of an unexplored concept like change agents.
Thin-shell wormholes with AdS black holes surrounded by Chaplygin dark fluid
Authors: Javed Faisal , Waseem Arfa , Mustafa Ghulam , Güdekli Ertan
Published: October 2023

In this paper, we inspect the stable geometry of thin-shell wormholes in the background of static spherically-symmetric AdS black holes solution bounded by dark fluid and Chaplygin-like equation of state [Formula: see text], where [Formula: see text] and [Formula: see text] denote the pressure and energy density that are related through positive constant [Formula: see text]. For this purpose, we consider the two equivalent copies of black holes and connected them at the hypersurface through cut and paste approach. Then, we employ the linearized radial perturbation to discuss the stability of the developed wormhole geometry by assuming variable equations of state. We obtain the maximum stable configuration for massive black holes for both barotropic and Chaplygin variable equations of state while for higher values of [Formula: see text], stable regions decrease. It is found that for every selection of physical parameters of black hole geometry with low intensity of Chaplygin dark fluid, we get the stable configuration of thin-shell wormholes.
Curved Electrostatic Nanobeams Incorporating Surface Energy
Authors: Khater Mahmoud E.
Published: October 2023

In this work, a study on curved electrostatically-actuated nanobeams incorporating surface energy is presented. The beam is modeled according to Euler–Bernoulli beam theory and the Gurtin–Murdoch theory of surface stress is used to incorporate surface energy effects in beam modeling. To verify the accuracy of the model, its predictions were compared to numerical results reported in previous literature on the static behavior of fixed-fixed and fixed-free nanobeams subjected to DC electrostatic potential. The results of this study demonstrate that the stiffness of both fixed–fixed and fixed-free nanobeams is influenced by surface stress. Furthermore, the findings highlight the significant impact of the electrostatic fringing field on the response of the nanobeams.
An Epigenetic Bi-stability of Structural Metamaterials Undergoing Dual Matching Shape-memory Effects
Authors: Liu Yuheng , Lu Haibao , Shu Dong-Wei , Huang Wei Min , Tao Ran
Published: October 2023

With the development of structural metamaterials and 3D printing technology, the polymorphic shape-memory metamaterials have attracted extensive attention. This study aims to design a structural 3D printed shape-memory metamaterial, of which the epigenetic bi-stability of shape-fixity and recovery behaviors have been achieved by means of the dual matching nominal moduli and geometrical size optimization. Epigenetic bi-stability and dual matching refer to the combination of bi-materials in a specific structure, in response to external stimuli to show adjustable bi-stability. Elastic thermoplastic polyurethane (TPU) and viscoelastic polylactic acid (PLA) both are thermally responsive shape-memory polymers (SMPs) and have been employed to fabricate the structural metamaterial, of which the nominal modulus is tailorable owing to the dual matching shape-memory effects (SMEs) of two SMP components. Furthermore, the effects of structural parameters, i.e., width of framework and width of internal support, on the nominal modulus have been investigated for the structural metamaterials, of which the shape-fixity and recovery ratios have been characterized using finite element method (FEM) analyses and experimental measurements. Finally, a constitutive relationship among structural parameters, dual matching SME and nominal modulus has been identified to explore the working principle of epigenetic bi-stability in shape-memory metamaterials. This study provides a design strategy for a shape-memory metamaterial with a post-switchable bi-stability, through dual matching SME and geometrical size optimization.
Authenticated Range Querying of Historical Blockchain Healthcare Data Using Authenticated Multi-Version Index
Authors: Linoy Shlomi , Ray Suprio , Stakhanova Natalia , Scheme Erik
Published: October 2023

With growing adoption of blockchain in established and emerging applications, there is an increasing need to support efficient ad hoc querying of authenticated historical data. This is especially true in fields such as healthcare to meet the rigorous security and regulatory requirements of ever-expanding digital health platforms. Existing blockchain systems, however, offer little or no support for querying capabilities over historical data. Although a full blockchain archive node can be used to maintain historical records of all executed transactions on the chain, it is not scalable when dealing with large volumes of data. Moreover, such ‘offline’ historical data lack tamper evidence support.

To address these issues, we introduce an authenticated index structure called Authenticated Multi-Version Skip List (AMVSL), designed to support a rich set of query features over historical blockchain data. We further present three range queries: SVRK, MVRK, and MVAK, which offer querying over a range of keys and a range of versions. Our experimental evaluation of two healthcare-inspired examples demonstrates that AMVSL efficiently supports these queries and can achieve performance that is several orders of magnitude faster than existing authenticated data structures.
Yield Optimization for Analog Circuits over Multiple Corners via Bayesian Neural Networks: Enhancing Circuit Reliability under Environmental Variation
Authors: Guo Nanlin , Peng Fulin , Shi Jiahe , Yang Fan , Tao Jun , Zeng Xuan
Published: October 2023

The reliability of circuits is significantly affected by process variations in manufacturing and environmental variation during operation. Current yield optimization algorithms take process variations into consideration to improve circuit reliability. However, the influence of environmental variations (e.g., voltage and temperature variations) is often ignored in current methods because of the high computational cost. In this article, a novel and efficient approach named
BNN-BYO
is proposed to optimize the yield of analog circuits in multiple environmental corners. First, we use a Bayesian Neural Network (BNN) to simultaneously model the yields and performances of interest in multiple corners efficiently. Next, the multi-corner yield optimization can be performed by embedding BNN into a Bayesian optimization framework. Since the correlation among yields and performances of interest in different corners is implicitly encoded in the BNN model, it provides great modeling capabilities for yields and their uncertainties to improve the efficiency of yield optimization. Our experimental results demonstrate that the proposed method can save up to 45.3% of simulation cost compared to other baseline methods to achieve the same target yield. In addition, for the same simulation cost, our proposed method can find better design points with 3.2% yield improvement.