bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Influence of Salt Marsh Vegetation on Tidal Current and Sediment Transport in Intertidal Zone
Authors: Chen M. Y. , Luo F. , Dai J. C.
Published: June 2023

Due to the sensitivity of the environment and immoderate human activities, the coastal zone in China is facing resource conflicts and environmental pressures. Salt marsh vegetation is regarded as an important measure for coastal ecological restoration. Therefore, it is of practical significance to study the influence of salt marsh vegetation on hydro-sediment dynamics. Based on the measured topography and tidal sediment data, a generalized model of salt marsh vegetation is established to study its effects on the dynamics of nearshore water and sediment. The results show that salt marsh vegetation has prominent effect of attenuating flow velocity and promoting sedimentation, and the ability differs depending on vegetation. Salt marsh vegetation can promote the development of tidal channels to shore, causing intensified erosion in the deep trough. The expansion of the vegetation area will allow the tidal channels to extend small branches to shore and connect with the vegetation front.
Simulation Study on Optimization Design of MEMS Hydrophone Based on AlN Film
Authors: Yu Qiankun , Zou Yongchao , Zhang Wen
Published: June 2023

In this paper, simulation study on optimization design of MEMS hydrophone based on AlN (Aluminum Nitride) film is carried out. Based on the theory of elastic mechanics and sound-solid coupling effect, the effect of film shape on the sensitivity and frequency response of the device is studied firstly. Results show that a square shape is beneficial to improving the overall performance of the device. The effects of piezoelectric film thickness and radius on the device performance are studied consequently. Results show that increasing the piezoelectric film radius significantly improves the device sensitivity. Finally, the effects of sandwiched and unequal-thickness piezoelectric structures on the device performance are investigated. It is found that unequal-thickness piezoelectric structures can remarkably improve the device performance. Results of this paper would support the performance improvement of MEMS hydrophones based on AlN film in future research work.
Design and Verification of Low Frequency Alternating Magnetic Field Detection Device Based on Unstable Platform
Authors: Zhao Zhe , Jiao Dawen , Hu Ping , Zhang Jing , Cui Pei , Lv Junjun
Published: June 2023

Low frequency alternating magnetic field is one of the important features for marine magnetic field detection. In order to realize the effective detection of low-frequency alternating magnetic field signal in the marine environment, a low-frequency alternating magnetic field detection device based on unstable platform was designed based on the low-power optical pump magnetometer and signal control processing circuit in this paper. The magnetic field signal can be stored. The power spectrum analysis, line spectrum purification, line spectrum extraction and so on can be processed online, and the processing results are saved and transmitted to the upper computer through serial communication. The test results of laboratory and offshore signal source show that the device has good ability of low frequency alternating magnetic field measurement, analysis and line spectrum extraction.
Design of Single-Polarized Single-mode Photonic Crystal Fiber Without Air Holes in the Cladding
Authors: Wang Weilong , Zhang Zejun , Liu Songjie , Wang Xiyin , Tsuji Yasuhide , Xu Jing
Published: June 2023

This study proposes a novel single-polarized single-mode (SPSM) photonic crystal fiber (PCF) without air holes in the cladding, and the silicon nitride holes and air holes in the core of the PCF are staggered. Based on the full vector finite element method, the birefringence characteristics with different hole sizes have been discussed in detail, and a SPSM-PCF is achieved through optimizing the core structure. Moreover, the extinction ratio, effective refractive index, dispersion, confinement loss and nonlinearity of the PCF are analyzed. Simulation results show that the PCF can obtain a high birefringence value of 2.142 × 10−3
, a large negative dispersion of −2750 ps/(nm · km), a low confinement loss of 1.57 × 10−7dB/m and a high nonlinear coefficient of 90.5W−1 · km−1
at the wavelength of 1.55 μm. In this paper, the proposed structure has the properties of high birefringence and high negative dispersion, which can be used in fiber laser, optical fiber sensing, dispersion compensation and other fields.
Scintillation Characteristics of Gaussian Vortex Beam Propagation in Turbulent Flume
Authors: Zhang L. , Wang Y. , Lin H. , Guo Y. , Jin F.
Published: June 2023

Aiming at the low sensitivity of weak turbulent wake detection of underwater vehicles, studied the laser propagation characteristics in underwater weak turbulence, and then proposed a method based on the statistical characteristics of the scintillation peak of Gaussian vortex beam for detecting the weak turbulence fluctuation. According to the refractive index power spectrum of turbulent flume, the intensity distribution images of Gaussian vortex beam propagating through turbulent flume are simulated by using the random phase screen method, and the scintillation characteristics of Gaussian vortex beam under different conditions are studied. For the simulation results, under the weak turbulence conditions with low refractive index structure coefficient, the average scintillation indexes near the peak value of spot scintillation indexes are obviously higher than those of the whole image. Under the condition that the temperature difference between hot plate and cold plate, between hot plate and water are about 6.4°C and 5.8°C, respectively, the scintillation indexes of the laser propagation intensity image under different temperature gradient (turbulence intensity) are calculated in the experiment. The results show that, the mean values of the scintillation indexes near the spot scintillation peak fluctuate around 1.02 and 1.07, and the mean values in whole image fluctuate around 0.58 and 0.68, respectively, when the temperature gradient is small, which verify the effectiveness of the statistical characteristics of the scintillation peak in detecting weak turbulence.
Error Analysis on Ultra-Short Baseline Positioning System
Authors: Yu Yang , He Chuanlin , Sun Shouyang , Liu Zeqi
Published: June 2023

Aiming at the problem of low accuracy of ultrashort baseline positioning system in practical applications, this paper introduces hydroacoustic channel response error and transducer distortion error, and analyses the influence of each factor on positioning accuracy in the positioning process according to the time delay estimation method. Finally, the major and minor factors are distinguished according to the influence mechanism and the degree of influence of the error factors. The results show that the ship attitude error and hydroacoustic channel error are the main factors affecting the positioning accuracy.
Influence and remedial measures of missing test data on magnetic field source location of underwater vehicle
Authors: Hu Ping , Jiao Dawen , Qi Jiahui , Chen Sidi
Published: June 2023

Due to the incomplete data collected, it will increase the difficulty of inversion location in the field source inversion of the static magnetic field data of underwater vehicles. Therefore, it is very necessary to study the influence of data loss on the static magnetic source location of underwater vehicles and the field source location for timely remedy of missing data. In this paper, the static magnetic equivalent source model of underwater vehicle was established. Then the inversion positioning algorithm was used to locate the magnetic field source of the underwater vehicle obtained from the test, and the influence of the location result under the incomplete data information was analyzed. We used deleting method, linear interpolation method and sliding filling method to populate the data to fill the remedy of missing data. Using the localization algorithm to carried out the inversion location of source, then we took the location of source inversion and the size of the magnetic dipole moment to the ellipsoid model to get fitting curve of magnetic field. The simulation curve of contrast verification test data with experimental data and the lack of remedial method was feasible. The results show that the missing data can not be ignored for the location of the underwater vehicle’s magnetic field source, and the data pairs filled with missing data can be effectively located for the equivalent static magnetic field source of the underwater vehicle through using deletion method, linear interpolation method and sliding filling method.
On the Reproducibility and Directionality of Underwater Laser-induced Acoustic Signal
Authors: Liu Qingxi , Song Wenhua , Tian Ye , Zhang Zeying , Yuan Guang
Published: June 2023

An intense laser pulse focused in water could induce plasma expansion, which can be used as an impulsive sound source. The optoacoustic underwater source is very useful in marine applications; however, the poor reproductivity and the sharp directivity of the emitted signals is a big problem. The reproductivity and directivity of the acoustic emission by laser breakdown are measured in the laboratory experiment in this paper, and the results show that the reproductivity and directivity are both direction-dependent. The measurement also shows the feasibility of improving the reproductivity and directivity by adjusting the focusing system of the laser beam.
SDPNet: A Novel DeepLearning Method for Ocean Surface Current Prediction
Authors: Zhang Zhiyuan , Yan Yan , Wang Zihe , Song Tao , Yin Jianping , He Xiyu , Guo Peiming , Wang Shaoke
Published: June 2023

Ocean surface currents (OSC), abiotic features of the environment, are continuous and directed movements of ocean water. Prediction to OSC is of significant interests in physical oceanography. Recently, deep learning technology has shown feasibility in mining the intrinsic change pattern of marine numerical values, such as SSS, SST and SSHA, but not been applied to OSC prediction yet. In this work, a deep learning method, named skipped dual path network (SDPNet), is proposed for OSC prediction. Specifically, SDPNet has a convolutional neural network (CNN) module with a one-dimensional convolution layer, and a recurrent neural network (RNN) module with a dual-path structure. Each path consists of a stack of three layers of long short-term memory (LSTM) and gated recurrent unit (GRU), respectively. As well, a skipped-connection structure is added in the both paths. It aims to gradually mine the intrinsic change pattern contained in OSC time series data itself. Experiments are conducted on the South China Sea OSC data set in REDOS. SDPNet achieves accuracy 80.83%, 75.9%, 74.9%, 73.9%, 72.58%, 70.35%, 69.93% in predicting the coming 7 days OSC values and directions. It performs better than state-of-the-art machine learning methods, include Artificial Neural Network, Simple RNN, LSTM and GRU.
A Convolutional Neural Network Combining Classification and Regression for Source Localization in Shallow Water
Authors: Liu Mingda , Niu Haiqiang , Li Zhenglin , Guo Yonggang , Liu Yining , Liu Jingben , Wu Shuanglin , Nie Leixin
Published: June 2023

Machine learning (ML) has been widely applied to ocean acoustic source localization. The localization problem is often regarded as a classification problem or a regression problem in the previous works. This paper proposes a convolutional neural network (CNN) combining classification and regression (CR-CNN) for source localization in shallow water with vertical array data. The normalized sample covariance matrices (SCMs) of the broadband data received by a vertical line array calculated by an acoustic propagation model are used as the input features of the network in the training process. The proposed method is verified by the observation data in the shallow water area of the East China Sea. The results of simulation and real data show that the performance of proposed method is better than that of the separate classification CNN (C-CNN) and MFP. And the localization results of the experimental data are basically consistent with the geoacoustic parameters sensitivity analysis. The depth estimation of the CR-CNN is much better than MFP, while the range estimation performance of CR-CNN, C-CNN and MFP are equivalent.
A Seabed Sediment Semantic Segmentation Method Based on Deep Transfer Learning with Self-Attention Mechanism
Authors: Zhang Y. S. , Li Y. Z. , Zuo L. J. , Deng K. L.
Published: June 2023

Semantic seabed sediment segmentation is one of the key research contents in the fields of marine resources development and marine engineering. In today’s intelligent and digitalized world, more refined semantic segmentation of seabed sediment can provide the basis for downstream tasks as building digital seabed models. In this paper, a seabed sediment semantic segmentation method based on deep transfer learning with self-attention mechanism is proposed. The overall framework is based on the UNet model. The transfer learning method of parameter sharing is used, while the parameters of backbone pretrained from ImageNet datasets are used as the initial weights of model. According to limited acoustic data of seabed sediment, this paper uses original side-scan sonar strip images to produce dataset. The proposed method is also compared with traditional machine learning methods as SVM (Support Vector Machine) and RF (Random Forest). The self-attention UNet (backbone: VGG16) model performed the best, with mIOU of 92.28%, mPrecision of 94.78%, and mRecall of 96.84% on the test set. The self-attention mechanism improved mIOU by 2.5%. The mIOU of deep learning methods is on average over 20% higher than that of traditional machine learning methods.
A Spatial Detection Method of Underwater Acoustic Target Based on Radiated Noise Features
Authors: Chen L. , Zhu C. Q. , An L.
Published: June 2023

In order to solve the problem that the traditional sonar detection method based on beam energy is not able to detect weak targets, a feature-based spatial beam target detection method is proposed in this paper. Firstly, the feature is extracted from the pre-formed beams in the whole spatial domain, and then using the relevance vector machine (RVM) for training, the probability output of target detection is obtained. Compared with traditional methods, this method can obtain excellent detection performance under the condition of low signal-to-noise ratio or signal-to-interference ratio. The probability output of this method can better represent the uncertainty of target detection, and it is also convenient for information fusion and other processing, which is different from the output of traditional binary detection. At the end of the paper, simulated data and experimental data both proved that this method is effective.
Adaptive Underwater Acoustic OFDM Modulation Method Based on Improved Deep Reinforcement Learning
Authors: Cui Xuerong , Yan Peihao , Li Juan , Li Shibao , Liu Jianhang
Published: June 2023

High environmental noise, narrow bandwidth, low carrier frequency, large transmission delay and other factors restrict the data transmission rate in underwater acoustic communication. To this end, improving communication quality and efficiency through adaptive adjustment is necessary for underwater acoustic communication system because of the restrict factor. The proposed method uses Deep Reinforcement Learning (DRL) to select the optimal transportation parameters and maximize the transmission efficiency with. The adaptive communication parameter setting is mapped into a Markov decision process with an unknown state transition probability. The system returns channel information including Channel State Information (CSI) and Signal Noise Ratio (SNR). We validate our estimation and adaptation techniques using the well-known simulator SWellEx_96 in varying underwater environments. Our results show that, for many practical cases, a dynamic adjustment of the prefix length, number of sub-carriers, filter length, and over-sampling factor may enable the utilization of OFDM modulations in underwater communications.
Study on effects of complex bathymetry on the deep acoustic field in Western Pacific Ocean
Authors: Zhou Xiaoyi , Duan Rui , Hao Wang , Gong Guangyu
Published: June 2023

Seafloor bathymetry has an important effect on acoustic propagation. In a deep water experiment in the Western Pacific in 2020, acoustic field in the reliable acoustic path (RAP) zone, the shadow zone, and the refracted zones were measured with shallow sources and deep receivers. Two important phenomena were observed. First, in the first shadow zone, the signal level (S) changing with source range presents a “W” shape: it sharply decreases by 19 dB after the source just pass the RAP boundary and then increases by 11 dB immediately, which produces the first S trough; after remaining stable for a range interval of 29 km, it drops again by 12 dB and then soars by 16 dB, which produces the second S trough. Secondly, the range spans of refracted zones that expected to be 29 km narrows down to only 13 km. Based on the precisely measured bathymetry and the range-dependent acoustic model-parabolic equation (RAM-PE), the S distribution were reproduced and its characteristics were explained. It was found that rather than the large-scale bathymetry change (e.g, large seamount or break shelf), it is the local bathymetry change that have significant effects on the S distribution.
Recognition of Whistle-like Signals Based on FM Harmonic Characteristics
Authors: Gui Y. , Cao H. L. , Wang X. Y. , An L.
Published: June 2023

While human hearing can easily identify whistle-like sounds made by dolphins and whales, manually identifying them from the increasingly variety and quantity of underwater acoustic signals (such as other marine life sounds and underwater acoustic communication signals) is undoubtedly laborious. To solve this question, a recognition method based on the frequency modulated feature and harmonic characteristic is analyzed in this paper. A harmonic energy analysis algorithm is proposed and is compared to a harmonic detection method. The experimental results prove that the proposed method could identify the whistle-like sounds with an accuracy over 90% and the traditional one could only reach 50%. The recognition method may be applied to the investigation of marine biological habits and the monitoring of marine ecological environment, and can also potentially be further applied to the detection of bionic communication signal.
The analysis of the depth dependence of ambient noise in the South China Sea
Authors: Ren C , Huang Y W
Published: June 2023

A 64-element vertical array was deployed in the South China Sea for ocean ambient noise observation. A rainstorm passed over the area during the experiment, lasting a total of 35 minutes. The differences between the depth distribution and vertical coherence of wind-driven noise and rain noise are compared, and the influence of rainfall rates on them is analyzed. The wind-driven noise intensity decreases with increasing depth, and it is basically consistent with the theoretical results. The depth distribution of rain noise is different from that of wind-driven noise. When the rainfall rate exceeds 48mm/h, the rain noise intensity in the frequency band above 3200Hz increases with increasing depth. Compared with wind-driven noise, the vertical coherence function depth distribution of rain noise is more uniform. The vertical coherence function of rain noise is in good agreement with the simulation results when the noise source directivity index take a larger value.
Acoustic radiation force on two-layered elastic sphere in standing wave field
Authors: Zhu J L , Wu Y S , Wu H Q , Zheng C H
Published: June 2023

A mathematical relationship between acoustic radiation force (ARF) on two-layered stratified elastic spheres immersed in water in acoustic standing wave field and dimensionless size parameter kr is established based on acoustic scattering theory. Calculating by using the relationship, we discussed the variation of ARF with kr under different conditions including changing the materials for shells or cores and changing the ratio of outer radium and inner radium. We find that the peaks of ARF have some linkage with different impedances of shells and different ratios of outer radium and inner radium.
Recursive Decoding Based Multi-channel M-ary Spread Spectrum Underwater Acoustic Communication
Authors: Wang Liang , Gao Mingyu
Published: June 2023

The spread spectrum communication method has strong anti-noise and anti-fading capability, but it also brings the problem of low information transmission efficiency. The paper proposes a multi-channel M-ary spread spectrum communication method, using a recursive decoding algorithm to reduce the communication bit error rate. In combination with the channel equalization technique based on the virtual time reversal mirror technique, the scheme improves the communication rate of spread spectrum communication. It is verified through computer simulation and sea trial data that the communication method can effectively reduce the mutual interference between different channel signals, which provides a new idea for the design of hydroacoustic spread spectrum communication scheme.
The polarization filtering line spectrum extraction algorithm of underwater target signal
Authors: Han Xue , Wang Yang
Published: June 2023

In order to increase the performance of underwater target line spectrum extraction, an adaptive polarization filtering line spectrum extraction method is researched in the paper. By using of the polarization characteristics of underwater target signals, the polarization characteristics of underwater target line spectrum signal is analyzed via singular value decomposition (SVD) method in frequency domain. Firstly, the line spectrum signal is presented by the eigenimage corresponding to the maximum singular value to increase the signal-to-noise ratio (SNR) of the signal. Then the polarization parameters are extracted according to the polarization characteristics of the line spectrum signals. And the line spectrum signal is filtered by constructing the polarization filtering function. The simulation results show that the output SNR of the proposed method are larger than that of conventional FFT analysis method when the SNR of the signal is larger than -9dB, and the detection probability of the proposed method is 100% when the SNR of the signal is -1 dB, while the detection probability of the conventional FFT analysis method is 27.73%. It shows that the proposed method provides a new approach for underwater line spectrum signal extraction techniques.
Pressure Sensitivity Kernel and Travel-Time Gradient for Geoacoustic Parameters Perturbations of Sediment in Shallow Water
Authors: Zheng J. , Zhang X. , Ma Z.
Published: June 2023

In shallow sea, the effect of geoacoustic characteristics of seabed sediments on acoustic propagation cannot be neglected, which is closely related to acoustic detection and seabed inversion. Aiming at the problem of low-frequency acoustic propagation, the sound pressure sensitivity kernel (PSK) and travel-time gradient (TTG) of the shallow low-frequency acoustic field for the geoacoustic parameters of sediment were presented by using normal mode model and perturbation approximation. Combined with the benchmark shallow sea model, the numerical simulation was carried out. The simulation results show that the PSK for the sound velocity of sediment are showing some interference pattern in velocity-range plane and velocity-frequency plane, and its strength is attenuated with the increase of range. TTGs have different sensitivity to the sound velocity of sediment at different range, which is more sensitive at mid-range. The PSK and TTG show some frequency selectivity.
Study on Catecholamine Sensors Based on Noble Metal Nanoparticles Modified Ti3C2 Mxene
Authors: Shou Jialong , Zhan Shuwang , Zhang Yi , Liang Bo , Fang Lu
Published: June 2023

Catecholamines are neurotransmitters in the peripheral and central nervous systems, which maintain the normal physiological state of the human body. Studies have shown that the occurrence of many diseases are often accompanied by changes in catecholamine levels. Clinically, the detection of catecholamine levels in human plasma or urine can assist in the diagnosis of endocrine-related diseases and neurological diseases. However, catecholamines are easily oxidized, and the content in human body is very low. So the rapid detection of catecholamines is very important for the prevention and diagnosis of related diseases. In this paper, the electrochemical response characteristics of Ti3C2Tx MXene and noble metal nanoparticles modified Ti3C2Tx to dopamine (one type of catecholamine) were explored. The results shown that Ti3C2Tx would undergo irreversible oxidation at the anode potential and the single Ti3C2Tx modified electrode was not suitable for the detection of dopamine. So we further explored the modification of Pt and Au nanoparticles on the Ti3C2Tx/GCE electrode, and the experimental results shown that Au/Ti3C2Tx/GCE had higher sensitivity for measuring dopamine, while Pt/Ti3C2Tx/GCE had a larger linear range. Both electrodes had good stability and repeatability and could be used for the detection of catecholamines.
Multi-Modal and Self-Reconstruction Conditioning Circuit of Semiconductor Gas Sensors
Authors: Wang Tao , Wu Yu , Ni Wangze , Zhu Jianbo , Zheng Mingxu , Zeng Min , Yang Jianhua , Yang Zhi
Published: June 2023

Semiconductor gas sensors (chemiresistors) have been widely used in many fields. The emerging novel gas sensors usually have large initial resistance and ultra-high sensitivity, and their resistance value may change significantly during the response process. It is difficult for conventional front-end conditioning circuits to meet the requirements of large measurement range and high accuracy. Meanwhile, the circuit needs to be compatible with several forms of signals generated from different types of sensors, such as voltage, current, and resistance. This study designs a front-end conditioning circuit that is compatible with various types of gas sensors and can adjust the measurement range in real time. The circuit has different functional states, which can realize four functions: constant voltage measurement, constant current measurement, electrochemical measurement, and parameter calibration. The modal transformation of the circuit is controlled by a multiplexer, which can perform automatic transformation according to software instructions. Our work provides a flexible circuit framework composed of different functional units, with the characteristics of multi-modal and self-reconstruction. It is suitable for designing integrated or fixed-function circuits and is convenient for miniaturization and cost reduction.
Influence Factors and Uncertainty Analysis of Relative Humidity Measured by Psychrometer
Authors: Liu Ying , Mo Hongbo , Wang Xiaolin
Published: June 2023

Based on the measurement principle of psychrometer and experimental data, the influence of wind speed on humidity measurement is analyzed, and the uncertainty of humidity measured by psychrometer is evaluated by GUM method. The research results show that under the condition of high temperature and high humidity, the relative humidity measured by psychrometer is not sensitive to wind speed. When the relative humidity is 90%RH and air temperature is 85°C, the difference of relative humidity calculated by using different psychrometer coefficients is 0.03% RH. With the decrease of dry-bulb temperature and relative humidity, the influence of wind speed on relative humidity measurement gradually increases. When the relative humidity is 20%RH and air temperature is 20°C, the difference of relative humidity calculated by using different psychrometer coefficients is 2.64% RH. The main uncertainty of relative humidity measured by psychrometer is introduced by psychrometer coefficient which is a function of wind speed. Measurement uncertainty decreases with the increase of relative humidity while at the same dry-bulb temperature.
Smart Insoles for Gait Analysis Based on Meshless Conductive Rubber Sensors and Neural Networks
Authors: Dai Yijie , Gao Jiale , Zhang Weidong , Wu Xingyi , Zhu Xiaobo , Gu Wenhua
Published: June 2023

In recent years, advances in wearable medical devices have been driven by the development of flexible sensors and wireless IoT technologies, with research and applications in this field rapidly increasing. Plantar pressure analysis is a gait method that can be used to analyze foot pressure during human movement to identify potential health problems, but most of the devices based on this method are currently single-functional, poorly portable, and expensive. This work proposes a smart insole using meshless conductive rubber sensors, as well as a multi-channel data acquisition and transmission system based on these sensors, deep learning networks, and Bluetooth technology. The smart insole sensing unit and circuit board were made of flexible materials and powered by rechargeable lithium batteries. The system can be used to collect plantar pressure data from the sensors in real time, analyze the pressure in different regions of the foot through a neural network, and infer the gait cycle and abnormal gait of the user. The effective communication range can be up to 70 meters under barrier-free conditions. This smart insole has a bright future thanks to the pressure detection range, fast response time, and good durability.
Domain-adversarial graph neural networks for Λ hyperon identification with CLAS12
Authors: McEneaney M. , Vossen A.
Published: June 2023

Machine learning methods and in particular Graph Neural Networks (GNNs) have revolutionized many tasks within the high energy physics community. Particularly in the realm of jet tagging, GNNs and domain adaptation have been especially successful. However, applications with lower energy events have not received as much attention. We report on the novel use of GNNs and a domain-adversarial training method to identify Λ hyperon events with the CLAS12 experiment at Jefferson Lab. The GNN method we have developed increases the purity of the Λ yield by a factor of 1.95 and by 1.82 using the domain-adversarial training. This work also provides a good benchmark for developing event tagging machine learning methods for the Λ and other channels at CLAS12 and other experiments, such as the planned Electron Ion Collider.
Electromagnetic design study of a superconducting longitudinal gradient bend magnet based on the HALF storage ring
Authors: Chen Chao , Wang Lin , Feng Guangyao , Li Weimin , Yang Penghui
Published: June 2023

The National Synchrotron Radiation Laboratory is planning to build a 2.2 GeV diffraction-limited storage ring, the Hefei Advanced Light Facility (HALF), with a 6BA lattice structure and a large number of longitudinal gradient bends (LGBs). In order to increase the radiated photon energy to the hard X-ray band and to reduce the natural emittance, a superconducting longitudinal gradient bend (SLGB) magnet is planned to be used on HALF in the future, which requires a magnetic field integral of 0.40 T·m over a length of 0.46 m and a peak field of about 5 T. A SLGB has many structural parameters, such as the geometric parameters of the superconducting coils and the thickness of the yoke, etc. Their influence on the magnetic field distribution has been studied, although the computation of the 3D magnet model is very slow. Considering the longitudinal field variation, the vertical gap limitation, the field homogeneity requirement and the critical current of the superconducting wire, a method is developed to simplify the 3D magnet simulation by a corresponding 2D model, so that the longitudinal magnetic field profile of a 3D model can be approximately calculated in a 2D model with faster speed. Due to the faster calculation speed of 2D models, a Mathematica-based optimization program is developed and relatively good structural parameters for the HALF SLGB are found by the program. The simulation results show that the physical design requirements can be well met. The electromagnetic design for the HALF SLGB magnet is based on the current JC
level of NbTi superconductor due to its excellent mechanical performance.
Linear colliders based on laser-plasma accelerators
Authors: Schroeder C.B. , Albert F. , Benedetti C. , Bromage J. , Bruhwiler D. , Bulanov S.S. , Campbell E.M. , Cook N.M. , Cros B. , Downer M.C. , Esarey E. , Froula D.H. , Fuchs M. , Geddes C.G.R. , Gessner S.J. , Gonsalves A.J. , Hogan M.J. , Hooker S.M. , Huebl A. , Jing C. , Joshi C. , Krushelnick K. , Leemans W.P. , Lehe R. , Maier A.R. , Milchberg H.M. , Mori W.B. , Nakamura K. , Osterhoff J. , Palastro J.P. , Palmer M. , Põder K. , Power J.G. , Shadwick B.A. , Terzani D. , Thévenet M. , Thomas A.G.R. , van Tilborg J. , Turner M. , Vafaei-Najafabadi N. , Vay J.-L. , Zhou T. , Zuegel J.
Published: June 2023

Laser-plasma accelerators are capable of sustaining
accelerating fields of 10–100 GeV/m, 100–1000 times that of
conventional technology and the highest fields produced by any of
the widely researched advanced accelerator concepts. Laser-plasma
accelerators also intrinsically accelerate short particle bunches,
several orders of magnitude shorter than that of conventional
technology, which leads to reductions in beamstrahlung and, hence,
savings in the overall power consumption to reach a desired
luminosity. These properties make laser-plasma accelerators a
promising accelerator technology for a more compact, less expensive
high-energy linear collider providing multi-TeV polarized leptons.
In this submission to the Snowmass 2021 Accelerator Frontier, we
discuss the motivation for a laser-plasma-accelerator-based linear
collider, the status of the field, and potential linear collider
concepts up to 15 TeV. We outline the research and development
path toward a collider based on laser-plasma accelerator technology,
and highlight near-term and mid-term applications of this technology
on the collider development path. The required experimental
facilities to carry out this research are described. We conclude
with community recommendations developed during Snowmass.
Experimental analysis of anodic coating process parameters of Al 5754 alloy by response surface method
Authors: Celik Ilhan , Erdemir Fatih , Coruhlu Isa
Published: June 2023

Aluminum 5754 alloy appears as a candidate material for many engineering applications in terms of its lightness and strength values. The surface properties of this alloy need to be improved for applications where there is surface damage such as friction and wear. In this study, Central composite design was applied to investigate the influences of anodic coating process parameters (voltage, coating time and grit size) on the response (i.e. surface roughness and coating thickness). The competence of the mathematical models recognized, and the importance of the regression coefficients were studied by ANOVA. The initial surfaces of the samples were sanded with 400, 800 and 1200 grit size and surfaces with 3 different roughnesses were obtained. Al 5754 specimens were anodic coated at 8 V, 12 V and 16 V voltages and combinations of time parameters of 10, 20 and 30 min The ANOVA results show that the designed models by RSM for average coating thickness and surface roughness are statistically important at the confidence level of 95%, and 80%, respectively. Maximum anodic coated layer of 29 μm was obtained at surface prepared with 1200 grit size, at 16 V of voltage and used for 30 min of anodizing time. The lowest roughness value of 0.676 μm was obtained at the surface was prepared with 1200 grit size, 8 V of voltage and anodizing time of 10 min.
The Australian Delirium Clinical Care Standard: not just another brick in the wall
Authors: Teodorczuk Andrew , Reade Michael C , Graham Frederick A
Published: June 2023

Delivering delirium care is challenging. Systems may not be set up to facilitate good delirium practice and staff may have low baseline understanding of how to spot, stop and treat delirium. In this context, delirium guidelines are especially important. In this article, we review the 2021 Australian Delirium Clinical Care Standards. The care standards are different to guidelines insofar as they focus on main presentations and represent eight quality statements describing the best evidence-based care patients with delirium should be offered.

The standards speak to three different audiences: consumer, clinician and healthcare organisations. As such, they provide some system-level solutions to practice-level problems. They incorporate latest evidence and reflect the sway away from prescribing to treat delirium, stating that antipsychotics should be avoided. Furthermore, they promote inclusivity of families and carers in delirium care processes as an important medium to engender good practice.

Limitations include the fact that they extend to delirium in multiple settings where different approaches may be necessary. They also lack the granularity of being able to provide recommendations on a greater range of drugs that might be used and assume settings are ready to introduce best delirium practice.

In sum, they represent an important step forward for delirium knowledge translation and are particularly relevant for patients in the geriatric setting. The guidelines though are constrained as to what they can advocate due to research gaps especially into treatment of delirium.
Sarcosine sensitivity in Escherichia coli is mediated by activation of the glycine cleavage system
Authors: Doroshenko Vera G , Slesareva Anna E , Shmonova Ekaterina A , Kivero Alexander D
Published: June 2023

Corynebacterium glutamicum AJ1511 and Escherichia coli BW25113 strains were compared in terms of resistance to sarcosine (N-methylglycine). The E. coli strain was more sensitive to sarcosine than C. glutamicum, especially when grown in minimal medium. Growth inhibition of the BW25113 strain in minimal M9 medium containing 0.5 m sarcosine was overcome by the addition of glycine. Inactivation of the glycine cleavage (GCV) system (∆gcvP) as well as the removal of its activator (∆gcvA) in BW25113 cells increased the threshold for sarcosine inhibition up to 0.75 m. Activation of the promoter of the E. coli gcvTHP operon by 0.1-0.4 m sarcosine added to M9 medium was demonstrated in vivo using dasherGFP as the reporter. Sensitivity to sarcosine on glucose minimal medium is suggested to be a characteristic of Gram-negative bacteria with GcvA/GcvR regulation of the GCV system.
Key questions for the evaluation of anti-amyloid immunotherapies for Alzheimer’s disease
Authors: Liu Kathy Y , Villain Nicolas , Ayton Scott , Ackley Sarah F , Planche Vincent , Howard Robert , Thambisetty Madhav
Published: June 2023

The clinical benefit associated with anti-amyloid immunotherapies, a new class of drugs for the treatment of Alzheimer’s disease, is predicated on their ability to modify disease course by lowering brain amyloid levels. At the time of writing, two amyloid-lowering antibodies, aducanumab and lecanemab, have obtained United States Food and Drug Administration accelerated approval, with further agents of this class in the Alzheimer’s disease treatment pipeline. Based on limited published clinical trial data to date, regulators, payors and physicians will need to assess their efficacy, clinical effectiveness and safety, as well as cost and accessibility. We propose that attention to three important questions related to treatment efficacy, clinical effectiveness and safety should guide evidence-based consideration of this important class of drugs. These are: (1) Were trial statistical analyses appropriate and did they convincingly support claims of efficacy? (2) Do reported treatment effects outweigh safety concerns and are they generalizable to a representative clinical population of people with Alzheimer’s disease? and (3) Do the data convincingly demonstrate disease course modification, suggesting that increasing clinical benefits beyond the duration of the trials are likely? We suggest specific approaches to interpreting trial results for these drugs and highlight important areas of uncertainty where additional data and a cautious interpretation of existing results is warranted. Safe, effective and accessible treatments for Alzheimer’s disease are eagerly awaited by millions of patients and their caregivers worldwide. While amyloid-targeting immunotherapies may be promising disease-modifying Alzheimer’s disease treatments, rigorous and unbiased assessment of clinical trial data is critical to regulatory decision-making and subsequently determining their provision and utility in routine clinical practice. Our recommendations provide a framework for evidence-based appraisal of these drugs by regulators, payors, physicians and patients.
Targeting neuronal mitophagy in ischemic stroke: an update
Authors: Li Jun , Wu Jiaying , Zhou Xinyu , Lu Yangyang , Ge Yuyang , Zhang Xiangnan
Published: June 2023

Cerebral ischemia is a neurological disorder associated with complex pathological mechanisms, including autophagic degradation of neuronal mitochondria, or termed mitophagy, following ischemic events. Despite being well-documented, the cellular and molecular mechanisms underlying the regulation of neuronal mitophagy remain unknown. So far, the evidence suggests neuronal autophagy and mitophagy are separately regulated in ischemic neurons, the latter being more likely activated by reperfusional injury. Specifically, given the polarized morphology of neurons, mitophagy is regulated by different neuronal compartments, with axonal mitochondria being degraded by autophagy in the cell body following ischemia–reperfusion insult. A variety of molecules have been associated with neuronal adaptation to ischemia, including PTEN-induced kinase 1, Parkin, BCL2 and adenovirus E1B 19-kDa-interacting protein 3 (Bnip3), Bnip3-like (Bnip3l) and FUN14 domain-containing 1. Moreover, it is still controversial whether mitophagy protects against or instead aggravates ischemic brain injury. Here, we review recent studies on this topic and provide an updated overview of the role and regulation of mitophagy during ischemic events.
Laparoscopic reconstruction in McKeown esophagectomy is a risk factor for postoperative diaphragmatic hernia
Authors: Takeuchi Akihiro , Ojima Toshiyasu , Hayata Keiji , Kitadani Junya , Goda Taro , Tominaga Shinta , Fukuda Naoki , Nakai Tomoki , Yamaue Hiroki , Kawai Manabu
Published: June 2023

Diaphragmatic hernia is a very rare but high-risk complication after esophagectomy. Although there are many studies on the Ivor Lewis esophagectomy procedure for diaphragmatic hernia, there are fewer studies on the McKeown procedure. The present study aimed to estimate the incidence of diaphragmatic hernia after esophagectomy, describing its presentation and management with the McKeown procedure. We retrospectively evaluated the 622 patients who underwent radical esophagectomy between January 2002 and December 2020 at the Wakayama Medical University Hospital. Statistical analyses were performed to evaluate risk factors for diaphragmatic hernia. Emergency surgery for postoperative diaphragmatic hernia was performed in nine of 622 patients (1.45%). Of these nine patients, one developed prolapse of the small intestine into the mediastinum (11.1%). The other eight patients underwent posterior mediastinal route reconstructions (88.9%), one of whom developed prolapse of the gastric conduit, and seven of whom developed transverse colon via the diaphragmatic hiatus. Laparoscopic surgery was identified in multivariate analysis as the only independent risk factor for diaphragmatic hernia (odd’s ratio [OR] = 9.802, p = 0.034). In all seven cases of transverse colon prolapse into the thoracic cavity, the prolapsed organ had herniated from the left anterior part of gastric conduit. Laparoscopic surgery for esophageal cancer is a risk factor for diaphragmatic hernia. The left anterior surface of gastric conduit and diaphragmatic hiatus should be fixed firmly without compromising blood flow to the gastric conduit.
Sex-Dimorphic Analyses Identify Novel and Sex-Specific Genetic Associations in Inflammatory Bowel Disease
Authors: Khrom Michelle , Li Dalin , Naito Takeo , Lee Ho-Su , Botwin Gregory J , Potdar Alka A , Boucher Gabrielle ,   NIDDK Inflammatory Bowel Disease Genetics Consortium,   International Inflammatory Bowel Disease Genetics Consortium, Yang Shaohong , Mengesha Emebet , Dube Shishir , Song Kyuyoung , McGovern Dermot P B , Haritunians Talin
Published: June 2023

Background

Sex is an integral variable often overlooked in complex disease genetics. Differences between sexes have been reported in natural history, disease complications, and age of onset in inflammatory bowel disease (IBD). While association studies have identified >230 IBD loci, there have been a limited number of studies investigating sex differences underlying these genetic associations.

Methods

We report the first investigation of sex-dimorphic associations via meta-analysis of a sex-stratified association study (34 579 IBD cases, 39 125 controls). In addition, we performed chromosome (chr) X–specific analyses, considering models of X inactivation (XCI) and XCI escape. Demographic and clinical characteristics were also compared between sexes.

Results

We identified significant differences between sexes for disease location and perianal complication in Crohn’s disease and disease extent in ulcerative colitis. We observed genome-wide-significant sex-dimorphic associations (P < 5 × 10-8) at loci not previously reported in large-scale IBD genetic studies, including at chr9q22, CARMIL1, and UBASH3A. We identified variants in known IBD loci, including in chr2p15 and within the major histocompatibility complex on chr6, exhibiting sex-specific patterns of association (P < 5 × 10-7 in one sex only). We identified 3 chrX associations with IBD, including a novel Crohn’s disease susceptibility locus at Xp22.

Conclusions

These analyses identified novel IBD loci, in addition to characterizing sex-specific patterns of associations underlying sex-dimorphic associations. By elucidating the role of sex in IBD genetics, our study will help enhance our understanding of the differences between the sexes in IBD biology and underscores a need to move beyond conventional sex-combined analyses to appreciate the genetic architecture of IBD more comprehensively.