Transmission Characteristics Research Articles

Genomic epidemiology of early SARS-CoV-2 transmission dynamics in Bangladesh.

Genomic epidemiology has helped reconstruct the global and regional movement of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there is still a lack of understanding of SARS-CoV-2 spread in some of the world's least developed countries (LDCs). To begin to address this disparity, we studied the transmission dynamics of the virus in Bangladesh during the country's first COVID-19 wave by analysing case reports and whole-genome sequences from all eight divisions of the country. We detected > 50 virus introductions to the country during the period, including during a period of national lockdown. Additionally, through discrete phylogeographic analyses, we identified that geographical distance and population -density and/or -size influenced virus spatial dispersal in Bangladesh. Overall, this study expands our knowledge of SARS-CoV-2 genomic epidemiology in Bangladesh, shedding light on crucial transmission characteristics within the country, while also acknowledging resemblances and differences to patterns observed in other nations.

Real-time full-duplex transmission experiment for an air and underwater invisible light communication system

Specifications for highly secure and large-capacity optical transceivers are necessary when wireless communication is used over different transmission channels, such as underwater and air, in shallow sea areas. We evaluated the dynamic characteristics of bidirectional real-time transmission using an LED Backhaul that can generate and process direct current-added orthogonal frequency division multiplexing signals in the 850 nm band to demonstrate the feasibility of invisibility light communication. A composite channel that is 1.2 m in water and 10 m in the air was used as an optical radio channel. This experiment is the first report on real-time and 4 K video stream transmission for a line-of-sight full-duplex optical wireless communication in the invisible light band via heterogeneous transmission channels such as shallow water and air.

Complexity and Variation in Infectious Disease Birth Cohorts: Findings from HIV+ Medicare and Medicaid Beneficiaries, 1999–2020

The impact of uncertainty in information systems is difficult to assess, especially when drawing conclusions from human observation records. In this study, we investigate survival variation in a population experiencing infectious disease as a proxy to investigate uncertainty problems. Using Centers for Medicare and Medicaid Services claims, we discovered 1,543,041 HIV+ persons, 363,425 of whom were observed dying from all-cause mortality. Once aggregated by HIV status, year of birth and year of death, Age-Period-Cohort disambiguation and regression models were constructed to produce explanations of variance in survival. We used Age-Period-Cohort as an alternative method to work around under-observed features of uncertainty like infection transmission, receiver host dynamics or comorbidity noise impacting survival variation. We detected ages that have a consistent, disproportionate share of deaths independent of study year or year of birth. Variation in seasonality of mortality appeared stable in regression models; in turn, HIV cases in the United States do not have a survival gain when uncertainty is uncontrolled for. Given the information complexity issues under observed exposure and transmission, studies of infectious diseases should either include robust decedent cases, observe transmission physics or avoid drawing conclusions about survival from human observation records.

Optimized Graph Sample and Aggregate‐Attention Network‐Based High Gain Meta Surface Antenna Design for IoT Application

ABSTRACTThis paper presents a High Gain Metasurface (HGM) antenna design optimized for IoT applications. The antenna operates at a 5.8 GHz frequency and utilizes a quarter‐wavelength unit cell structure. The design employs a Graph Sample and Aggregate‐Attention Network (GSAAN) to enhance the transmission characteristics of the metasurface. To optimize the performance of GSAAN, the Giza Pyramids Construction Algorithm (GPCN) is applied to adjust the weight parameters, leading to significant improvements in radiation efficiency, bandwidth, gain, directivity, and return loss. The proposed HGM antenna is simulated in MATLAB 2023b, where it demonstrates substantial performance gains over existing methods. Specifically, the proposed design achieves 28.34% higher gain compared to the MSA‐RHCOA method, 24.47% improvement over HGM‐AD‐MATCS, 26.34% better gain than BR‐HGA‐PGM, and a 32.12% gain increase relative to MSA‐Hyb‐ADSA‐HMSOA. These enhancements make the proposed antenna design a competitive solution for high‐gain applications in wireless communication, satellite communication, and radar systems. The integration of GSAAN with GPCN optimization in the HGM antenna design enables the creation of highly directive radiation patterns, making it well‐suited for IoT applications that require high performance and reliability. The results of this study demonstrate the effectiveness of the proposed approach in achieving superior antenna performance, positioning it as a strong alternative to existing metasurface antenna designs.

Optimizing Na2EDTA Concentration for Enhanced Properties of SILAR - Deposited CTS Thin Films

Abstract This study investigates the impact of varying Na2EDTA concentrations on the properties of copper tin sulfide (CTS) thin films deposited on soda lime glass substrates using the successive ionic layer adsorption and reaction (SILAR) method. The aim is to optimize CTS thin film growth for photovoltaic technology applications. CTS thin films were prepared using SILAR with Na2EDTA concentrations of 0.01M, 0.04M, and 0.07M, resulting in samples CTS01, CTS04, and CTS07. Characterization techniques included XRD, SEM, EDAX, FTIR, I-V curves, transmittance spectra, and Tauc plots. The results reveal significant variations in film properties with changing Na2EDTA concentration. XRD patterns indicate polycrystalline films with an orthorhombic CTS phase. SEM images show smooth, dense films with localized clusters. FTIR spectra detect hydrocarbon chains, aromatic rings, and hydroxyl or ether groups. The I-V curves of three samples (CTS01, CTS04, and CTS07) show a voltage-dependent transition from semiconducting to ohmic behavior. The CTS01 exhibits superior conductivity (3.13x10-5/Ωm), while the samples' resistance and conductivity values show an inverse relationship. Transmittance curves display low UV transmittance and high visible transmittance,suggests that the samples are highly absorptive in the UV range and become more transparent in the visible range, indicating potential applications in optical filtering and photovoltaic devices. Tauc plots estimate band gap energies of 3.66, 3.89, and 3.23 eV, indicating high band gap energies suitable for buffer layers in solar cells. The correlation between band gap energy and crystallite size as a function of Na2EDTA concentration is also observed. The study demonstrates the importance of optimizing Na2EDTA concentration for achieving high-quality CTS thin films with desirable properties for photovoltaic applications. The findings highlight the potential of CTS thin films for solar cells, optical filtering, and photonic devices.

Model for restoring obstructed beam transmission in atmospheric turbulence based on BP neural network

Atmospheric turbulence and obstacles can distort rays during transmission, resulting in significant wavefront distortion and loss of optical field information. This paper employs the phase screen method to simulate the transmission characteristics of a Gaussian plane wave in turbulent conditions, establishing an obstacle grid at the receiver to represent beam obstruction. A dataset of unobstructed transmissions is used to train a Backpropagation Neural Network, constructing neurons and connection weights. By scanning optical field data systematically, the model compensates for the obstructed portions of the optical field distribution. The results are compared to unobstructed transmissions, focusing on image similarity, and demonstrate the entire process from compensation to distortion correction. Simulation results indicate that the Backpropagation Neural Network effectively compensates for optical field information loss, showcasing strong performance within a certain time scale.

Advanced design strategies and applications for enhanced higher-order multisegment denatured Pascal curve gears

The existing Pascal curve gears are limited by inflexible pitch curves and constrained transmission ratio changes, which hinders the application in a range of mechanical systems that require more adaptable gear solutions. To address this, a design procedure for higher-order multisegment denatured Pascal curve gear is proposed. A unified mathematical expression for the Pascal curve gear family is derived, enabling the construction of non-circular gears with free-form pitch curves by adjusting key parameters and offering more flexible pitch curve and a wider range of transmission ratios. Compared with elliptical gears and eccentric circular gears, its transmission ratio range can be expanded by up to 35%. Then the transmission characteristics of these gears are analyzed in detail. To validate the design, the visual analysis and design software of the gear is compiled based on Visual Basic, and is verified with the example. The novelty Pascal curve gears is applied to drive the differential velocity vane pump. The displacement, instantaneous flow rate, and pulsation rate of the differential velocity vane pump are calculated. The comparison with the differential pumps driven by eccentric non-circular gears and Fourier non-circular gears shows that when the pitch curves are not concave, the displacement driven by Pascal curve circular gears is the highest (compared to differential pumps driven by eccentric non-circular gears, and Fourier non-circular gears, their flow rates increased by 50.6%, and 175.7%, respectively), and the instantaneous flow pulsation rate of single pump is the smallest.This study shows that the higher-order multisegment denatured Pascal curve gear provides a viable solution for systems requiring flexible transmission mechanisms and improved operational performance.

Infantile Pasteurella multocida Meningitis: Case Report and Review of the Literature

Background: Pasteurella multocida is a rare cause of deep-seated pediatric infections including osteomyelitis and meningitis. We report a case of P. multocida meningitis from Queensland, with a comprehensive review of literature. Methods: Three databases were searched for infants < 12 months of age with confirmed P. multocida meningitis. Mode of transmission, clinical and laboratory features, imaging, treatment and complications were reviewed. Logistic regression analysis was performed to evaluate predictors for outcomes including short-term neurologic complications, any long-term complications and mortality. Results: A total of 74 infants were included, with most cases occurring from indirect household animal contact (42/74; 61%). Bacteremia (38/74; 51%) and seizures (15/74, 20%) were common complications with mortality in 6 children (8%). Young infant age appeared to be the single most important risk factor for bacteremia. Conclusions: Infantile P. multocida meningitis although rare has potentially devastating complications. Younger infants are more likely to develop concomitant bacteremia. Household hand hygiene is imperative after trivial interactions with pets.

Transmission characteristics of vortex light superposition in atmospheric turbulence disturbed by plane acoustic waves

Herein, we derive the expression for the atmospheric refractive index structure constant under the influence of planar acoustic wave perturbations under the influence of the acoustic field on the refractive index and energy of the atmosphere. Utilizing the low-frequency compensated power spectrum inversion technique, we simulate the refractive index power spectrum of atmospheric turbulence perturbed by a planar acoustic wave. Numerical analysis is conducted on the transmission characteristics of the vortex light superposition states in atmospheric turbulence perturbed by a plane acoustic wave under different acoustic wave transmission heights, acoustic pressure amplitudes, and frequencies. Results indicate that introducing an acoustic field induces fluctuations in the atmospheric refractive index structure constant, with a more pronounced impact on the refractive index than on energy. Compared with the sole consideration of the impact of the acoustic field on the atmospheric refractive index, incorporating its effect on atmospheric energy results in a decrease in the atmospheric refractive index structure constant. The impact of the acoustic field on atmospheric turbulence is directly proportional to both acoustic pressure amplitude and frequency. The influence of the acoustic field on the transmission properties of the vortex optical superposition state varies with different acoustic transmission distances. Consequently, the transmission characteristics of the vortex light superposition state can be actively modulated according to varying acoustic wave transmission distances. This study offers a theoretical basis for modulating the optical field transmission characteristics via acoustic fields.

Study on the carrier transmission and luminescence characteristics of n-ZnO/p-Si heterojunction device by magnetron sputtering

Study on the carrier transmission and luminescence characteristics of n-ZnO/p-Si heterojunction device by magnetron sputtering

Heat transport analysis of three-dimensional Magnetohydrodynamics nanofluid flow through an extending sheet with thermal radiation and heat source/sink

Regarding heat transformation efficiency, the hybrid nanofluid performs superior to the nanofluid. The majority of hybrid nanofluid uses are in the industrial sector, producing solar energy, cooling generators, and vehicle heat transformation. Heat transfer and nanofluid velocity are the two most crucial transport properties that must be evaluated before the first and second thermodynamics equations are applied to nanoscale fluids. The objective of this work is to investigate the characteristics of transmission of heat of magnetohydrodynamic (MHD) nanofluid (Ag/H2O)and hybrid nanofluid (Ag+Al2O3/H2O)flow on a linear extensible sheet when magnetic forces are present. Similarity variables are applied to transform a set of nonlinear dimensionless partial-differential equations to collection of ordinary-differential equations. The non-analytical solutions of these transformed equations are found utilizing the MATLAB mathematical program's bvp4c function. The impression of various physical attributes along skin friction coefficients and properties of heat transmission are analyzed. The behavior of key parameters, including surface stretching ratio, rotational and magnetic effects, for temperature and velocity, is shown using graphs and tables. In conclusion, hybrid nanofluids, which comprise silver and aluminum oxide nanoparticles dispersed in water, outperform silver-water nanofluids by around 10-15% under magnetohydrodynamic (MHD). The higher thermal conductivity of these hybrid nanofluids allows for better heat dissipation, making them an appealing option for applications that need optimal thermal management in the presence of magnetic fields.

Transmission Network and Phylogenetic Analysis Highlight the Role of Suburban Population in HIV-1 Transmission Among Older Adults in Nanjing, Jiangsu Province, China.

Describing the transmission characteristics among older adults is essential for designing tailored interventions. An epidemiological investigation combined with phylogenetic analysis was conducted to reveal potential transmission linkages among older adults in Nanjing. Between 2018 and 2022, 188 pol sequences were successfully amplified. Multiple genotypes were identified, including CRF07_BC (55.3%), CRF01_AE (30.3%), CRF08_BC (8.0%), B (3.2%), CRF55_01B (1.1%), CRF67_01B (0.5%), CRF68_01B (0.5%), and unique recombinant forms (URF) (1.1%). Transmission network analysis identified 120 genetically linked patients forming 23 clusters, ranging from 2 to 26 individuals. Multivariable logistic regression analysis showed that compared with farmers and heterosexuals, patients with other occupations (OR = 0.404, 95% CI: 0.173-0.945) and MSM (OR = 0.193, 95% CI: 0.050-0.738) were less likely to have high linkage. Subjects who lived in suburban areas were more likely to have high linkage (OR = 10.932, 95% CI: 3.335-35.830). The Sankey diagram suggested that patients living in suburban areas primarily transmitted the disease within the local district (χ2 = 24.192, p < 0.001). Among the 188 pol sequences, the prevalence of pretreatment drug resistance was 8%. In suburban areas with a rising HIV-1 epidemic, improving early detection and timely treatment is critical. More tailored interventions for this subgroup are urgently needed.

Long-wave infrared multi-spectral filter arrays based on surface plasma polaritons

An infrared multi-spectral filter based on surface plasmon polaritons is proposed in this study. It is used to achieve optical filtering in the long-wave infrared range of 8-14μm. After coupling with the plasma polaritons excited on the surface of Au film, the incident light propagates through periodic sub-wavelength through-holes. We analyzed the transmission characteristics of the filter with periodic sub-wavelength through-holes and its local field distribution using the Finite-Difference Time-Domain (FDTD), and carried out the tolerance analysis to demonstrate the possibility of large-scale and low-cost processing. The simulation results indicated that our proposed filter attained four spectral channels in the spectral range of 8 to 14 μm with peak energy transmittance up to about 60%, and wide tolerances as well as polarization-insensitive characteristics. Our proposed long-wave infrared filters can provide efficient and low-cost solutions for lightweight multi-spectral devices and all-weather detection.

Isolation, Molecular Characterisation, and Pathogenicity Analysis of a Novel Recombinant ALV-J Strain Isolated From Chinese Hetian Chickens.

Avian leukosis virus subgroup J (ALV-J) primarily affects poultry, particularly chickens, leading to tumourigenesis and immunosuppression, which results in substantial economic losses. It is important to note that ALV-J is commonly found in indigenous chicken breeds in China, and the virus's vertical transmission characteristics present a significant threat to the preservation of local chicken breeds. The study aimed to investigate the characteristics and effects of the recombinant ALV-J strain LY2021J, with a focus on its genetic composition and its potential influence on virulence and pathogenicity. LY2021J was isolated using DF-1 cells and validated by enzyme-linked immunosorbent assay (ELISA) and IFA. The proviral genome was amplified using segmented PCR and then spliced together using DNASTAR software. Genome-wide genes, including gag, pol, gp85, and long terminal repeat (LTR), were compared. Recombination sites were analysed using RDP5 and SimPlot software. Pathogenicity was evaluated by monitoring symptoms and conducting examinations on SPF chickens. The outbreak of ALV-J in China has caused significant economic losses in the poultry industry. Although largely controlled in white-feather broilers and egg-laying chickens, ALV-J has spread to yellow-feather broilers and local breeds. A strain, LY2021J, isolated from Hetian chickens, showed lower mortality despite severe dysplasia. Genetic analysis revealed high similarity between LY2021J and the Chinese strains JS14NT01 and NX0101, suggesting a shared origin. Recombination with strain ev-1 and specific 3' UTR deletions may explain LY2021J's reduced virulence. Continued monitoring and prevention strategies are essential to mitigate ALV-J's impact.

Optimization of territorial ecological space under the constraint of ecosystem service externalities

Ecosystem services are dynamic, following specific paths between regions and generating externalities. However, research on these externalities and the mechanisms within ecological networks remains limited. The quantification, spatial patterns, and evolution of these externalities are still unclear and need further study. Utilizing land use, topography, precipitation, and socio-economic data from 2010 and 2020, the study aims to quantify the externalities of ecosystem services and analyze their spatial distribution and network transmission characteristics within the Territorial Ecological Space (TES) of Jintan District. Using the InVEST model, we assessed the externalities of ecosystem services and integrated these with an ecological network model to reveal the impact of network structure on the flow of externalities. We propose an ecological space optimization plan with various scenarios, offering a reference for regional ecological space optimization. Key findings indicate that ecosystem service externalities exist and display spatial differentiation, with ecological source areas and corridors participating in the flow and dissipation of these services. Based on these findings, an ecological space optimization plan is proposed, consisting of multiple scenarios, which offers a reference for regional ecological space optimization. The study contributes to the sustainable management of ecological spaces by providing new insights and methodological advancements, particularly in the context of optimizing ecological spatial structures and ensuring regional ecological security. By elucidating the spatial dynamics and network transmission of ecosystem service externalities, this research supports informed decision-making in ecological conservation and land use planning.

Order Degree and Centrality Analysis of Advanced Fighter Environmental Control System and Thermal Management System

As fighter aircraft become more advanced, traditional air cycle systems have fallen short of meeting the complex environmental control requirements. Advanced fighters such as the F-22 Raptor have responded to these challenges by adopting integrated thermal management systems. These systems feature complex thermodynamic processes and intricate information transmission pathways among various components, creating a sophisticated network structure. To unravel the complexity of such systems, this paper employs a blend of thermodynamics and information theory. We conduct multi-level analysis using structure entropy method and centrality algorithms to explore the information transmission characteristics within these thermodynamic systems. At the system level, we find that variation in environmental parameters have only a 1% impact on order degree, whereas the influence from the system's own structure is more pronounced. At the component level, within the whole system, the varies components in AFT PAO and fuel loops emerge as critical hubs for information transmission. Among these components, the PAO/Fuel stands out as the most important, with closeness and betweenness centrality exceeding that of all other components by at least 11.5% and 29.1%. This study offers a theoretical foundation for the optimization of thermodynamic system structure and layout, viewed through the lens of information theory.

Simulation of the electromagnetic scattering characteristics in inductively coupled plasma array for aircraft stealth

Abstract In this paper, an electromagnetic model of an inductively coupled plasma (ICP) array is developed to investigate its electromagnetic transmission characteristics under varying discharge conditions. The reliability of the model is enhanced by basing plasma parameters on simulation results from a fluid dynamics model. Electromagnetic simulations analyze the reflection spectrum of the inductively coupled plasma array, revealing the modulation mechanism of the plasma array. Findings indicate that as excitation power increases, the attenuation peak of the ICP array shifts to higher frequencies, and the attenuation bandwidth widens. By employing different power levels for the two layers in the Inductively Coupled Plasma (ICP) process, the array can achieve effective stealth performance with lower power consumption. Adjusting plasma discharge parameters to match specific scenarios enables the proposed plasma array to achieve varied modulation effects, expanding its potential applications in aircraft stealth.

A passive, flexible dual-function sensor for simultaneous pressure and sliding direction detection

Flexible pressure and omnidirectional slide sensors show significant potential in wearable devices and robotics. However, the integration of various sensor types to achieve multi-functionality introduces challenges. Complex structures and processing difficulties limit their miniaturization and flexibility, while dependence on external power sources further constrains their practical use. Here, we report a novel strategy that utilizes a piezoelectric-conductive nanoresistance network with edge electrodes to develop an advanced pressure sensor. This sensor is capable of simultaneously detecting pressure and sliding direction through multiple-channel pulses. We demonstrate its functionality using a polyacrylonitrile/polypyrrole nanofiber membrane (PAN/PPY NFM) configured with either two or three electrodes. By exploiting the signal transmission characteristics of the nanoresistance network, the sensor simultaneously responds to both force and sliding direction through amplitude-frequency analysis of the output signals from multiple channels. Additionally, the sensor operates without an external power supply. This streamlined approach simplifies sensor design and processing, providing a promising solution for advanced touch sensing applications.

Design and Application of a Lightweight Plate-Type Acoustic Metamaterial for Vehicle Interior Low-Frequency Noise Reduction

To reduce the low-frequency noise inside automobiles, a lightweight plate-type locally resonant acoustic metamaterial (LRAM) is proposed. The design method for the low-frequency bending wave bandgap of the LRAM panel was derived. Prototype LRAM panels were fabricated and tested, and the effectiveness of the bandgap design was verified by measuring the vibration transmission characteristics of the steel panels with the installed LRAM. Based on the bandgap design method, the influence of geometric and material parameters on the bandgap of the LRAM panel was investigated. The LRAM panel was installed on the inner side of the tailgate of a traditional SUV, which effectively reduced the low-frequency noise (around 34 Hz) during acceleration and constant-speed driving, improving the subjective perception of the low-frequency noise from “very unsatisfactory” to “basically satisfactory”. Furthermore, the noise reduction performance of the LRAM panel was compared with that of traditional damping panels. It was found that, with a similar installation area and lighter weight than the traditional damping panels, the LRAM panel still achieved significantly better low-frequency noise reduction, exhibiting the advantages of lightweight, superior low-frequency performance, designable bandgap and shape, and high environmental reliability, which suggests its great potential for low-frequency noise reduction in vehicles.

Distance Health Services Organization in University Hospitals: The Case of a Public University Hospital

In today's globalized healthcare market, it has become a necessity for healthcare organizations to strive to provide the healthcare services needed by their target audience with modern medical technology and software, regardless of physical space, country and/or geography. In fact, although distance health services and tele-medicine applications are not new applications, they have been increasingly used by healthcare organizations due to the physical transmission feature of the New Coronavirus Disease (Covid-19) or corona pandemic. The aim of this study is to analyze the legal dimension of Distance Health Services (DHS) in a public university hospital, the path to be followed to obtain a “Distance Health Service Activity Permit Certificate”, the characteristics, quantity and qualifications of the human resources to provide health services, the physical structure of the areas to be served and the information technologies, information systems to be used, the ministry audit criteria related to the pricing, invoicing and refund methods of health service fees, and to contribute to the structuring stages of distance health services of similar health institutions.