bluuebunny/crossref_metadata_2025 huggingface dataset:
Underwater Sea Cucumber Identification Based on Improved YOLOv5
Authors: Zhai Xianyi , Wei Honglei , He Yuyang , Shang Yetong , Liu Chenghao
Published: September 2022

In order to develop an underwater sea cucumber collecting robot, it is necessary to use the machine vision method to realize sea cucumber recognition and location. An identification and location method of underwater sea cucumber based on improved You Only Look Once version 5 (YOLOv5) is proposed. Due to the low contrast between sea cucumbers and the underwater environment, the Multi-Scale Retinex with Color Restoration (MSRCR) algorithm was introduced to process the images to enhance the contrast. In order to improve the recognition precision and efficiency, the Convolutional Block Attention Module (CBAM) is added. In order to make small target recognition more precise, the Detect layer was added to the Head network of YOLOv5s. The improved YOLOv5s model and YOLOv5s, YOLOv4, and Faster-RCNN identified the same image set; the experimental results show improved YOLOv5 recognition precision level and confidence level, especially for small target recognition, which is excellent and better than other models. Compared to the other three models, the improved YOLOv5s has higher precision and detection time. Compared with the YOLOv5s, the precision and recall rate of the improved YOLOv5s model are improved by 9% and 11.5%, respectively.
A Maximum Power Point Tracking Control Method Based on Rotor Speed PDF Shape for Wind Turbines
Authors: Zhang Xinge , Zhang Zhen , Jia Junru , Zheng Liming
Published: September 2022

Maximum power point tracking (MPPT) is the key to improve the conversion efficiency of wind energy. Concerning the current research on the MPPT control, based on the accurate tracking of rotor speed probability density function (PDF) shape for wind turbines, a novel MPPT algorithm was introduced in detail to improve the power capture and reduce mechanical damage for wind turbines. Considering the influence of wind speed distribution on the wind power generation system performance, this paper expounds a PDF shape control method of a stochastic system based on the Fokker–Planck–Kolmogorov (FPK) equation. Combining the conventional optimal torque (OT) control algorithm with the FPK equation solved by linear least-square (LLS) method, the novel MPPT control law is designed to make the PDF shape of rotor speed track the desired PDF shape as accurately as possible. The simulation verification of the novel MPPT method is carried out in the 1.5 MW wind turbine system. The results reveal that the novel MPPT method can improve the conversion efficiency of wind energy, reduce the frequent fluctuations of system variables, and significantly optimize the performance of wind power generation system.
Multi-Physics Analysis of a Magnetorheological Valve Train with Experimental Validation
Authors: Shiao Yaojung , Kantipudi Mahendra Babu
Published: September 2022

Magnetorheological (MR) fluid devices are widely used in active automotive control applications. However, MR fluid-based valve actuators are not in the limelight. This paper proposes a new flexible valve train with an MR fluid control system; the valve train can enhance the performance of internal combustion engines. A major component of this valve train is the magnetic plate block filled with MR fluid and surrounded by a magnetic coil. This plate block controls the magnetic field in this MR fluid and eventually facilitates flexible valve lifts and valve opening timings. This study overviewed the conceptual design, two-way coupled multi-physics numerical simulations, manufactured an MR valve prototype, and conducted experimental tests on a test bench to understand the real-time performance of the MR valve train. First, computer simulations were performed using a coupled magnetic and thermal multiphysics model to consider the Joule-heating effect of the magnetic coil in the MR magnetic plate block. The simulation results indicated that although the temperature of the MR fluid increased noticeably, it did not exceed the prescribed operating limits. The dimensions of the MR magnetic plate block were optimized. After computer simulations and optimization, a prototype of the proposed MR valve was fabricated and tested to understand its performance in real time. The experimental test results indicated the reliability of the proposed MR valve train in practical scenarios.
Psychoeducation on Stress and Anxiety Using Virtual Reality: A Mixed-Methods Study
Authors: Pallavicini Federica , Orena Eleonora , Achille Federica , Cassa Maddalena , Vuolato Costanza , Stefanini Stefano , Caragnano Chiara , Pepe Alessandro , Veronese Guido , Ranieri Paolo , Fascendini Sara , Defanti Carlo Alberto , Clerici Massimo , Mantovani Fabrizia
Published: September 2022

Virtual reality can help individuals to manage stress and anxiety. In addition to its efficacy in reducing stress and anxiety through relaxation, virtual reality can be helpful for psychoeducation. However, to date, few studies have explored this topic. Therefore, this mixed-methods sequential explanatory study, aimed to investigate the usability, sense of presence, emotional response, and effect on learning of MIND-VR, a psychoeducational virtual experience created to offer information on stress and anxiety. Twenty healthcare workers (60% female; mean age 43 ± 10) tried MIND-VR. Psychometric outcomes served as quantitative variables, while participant interviews provided qualitative data. Results showed that the virtual reality psychoeducational experience: (a) was highly usable and satisfying; (b) increased positive emotions (i.e., happiness and surprise) and decreased negative emotions (i.e., fear, sadness) and state anxiety; (c) elicited a strong sense of presence, especially spatial presence; and (d) was practical, simple, motivating, and engaging for learning information about stress and anxiety. These findings offer promising insights into that virtual reality may be an effective tool to provide psychoeducation.
Robot Routing Problem of Last-Mile Delivery in Indoor Environments
Authors: Kim Junsu , Jung Hosang
Published: September 2022

With the development of robot technology, trials adopting robots for last-mile delivery are continuing, and the final destination of last-mile delivery is further expanding into indoor environments. Unlike existing studies conducted for robot-based last-mile delivery in outdoor environments, two main issues must be solved to enable last-mile delivery in indoor environments using robots. First, it is necessary to reasonably and realistically estimate the robot travel time considering horizontal and vertical movement segments within a given building. Second, optimizing the robot routing problem based on the estimated robot travel time is necessary. In this paper, we proposed a new method to estimate the robot travel time considering robot movement characteristics and an elevator in a building. In addition, we developed a mathematical model of the robot routing problem and problem-specific heuristic based on a genetic algorithm to quickly solve the proposed mathematical model. It obtained the exact solutions when the problem size was small and near-optimal solutions in the medium- and large-sized problems (average optimality gap: 0.11% and 0.18%, respectively). Through extensive experiments assuming various building structures, it was determined that the proposed model and heuristic can quickly yield realistic solutions for indoor robot-based last-mile delivery.
Evaluation of Liquefaction Properties of East Coast Sand of New Zealand Mixed with Varied Kaolinite Contents Using the Dynamically Induced Porewater Pressure Characteristics
Authors: Kalatehjari Roohollah , Bolarinwa Ademola
Published: September 2022

In earthquake geotechnical engineering, physical model experiments have proven to be significant and valuable in understanding the complex physics and engineering behaviors of prototype undrained soils in fields. An executed literature review indicated that large-scale physical model testing, such as shaking table (ST) and centrifuge devices, have associated advantages and limitations. The current paper presents the design, fabrication, and calibration of a 600N-capacity, small-scale, one-directional (1-D) laboratory ST device that enables quick and valuable assessment of soil liquefaction mechanisms. The dynamically induced porewater pressure (PWP) generation characteristics of sand soil mixed with different percentage weights of clay were evaluated and illustrated as a case study for testing the ST device’s performance. The east coast sand (ECS) of New Zealand’s North Island was mixed with different percentages of kaolinite clay to produce five variants of ECS (00, 05, 10, 20, 25, and 30). Three input sine wave ground motions of a constant frequency of 10 Hz and amplitudes of 2, 3, and 4 were applied and classified in the current study as low, intermediate, and moderate ground motions, respectively, to evaluate the evolution of the dynamic excess pore pressures in the soil samples. The results indicated that the clean ECS and mixed samples with lower clay content (ECS00, ECS05, ECS10, and ECS15) produced the highest excess PWP throughout the three shaking cycles, with higher tendencies of contraction and liquefaction properties. On the other hand, soil samples with a higher percentage of clay (ECS20 and ECS20) yielded the lowest PWP, with softening and dilative properties.
Influence of Small Radius Curve Shield Tunneling on Settlement of Ground Surface and Mechanical Properties of Surrounding Rock and Segment
Authors: Lou Ping , Li Yonghe , Xiao Hongbo , Zhang Zhengang , Lu Shide
Published: September 2022

Compared with straight tunnels, over-excavation occurs on the inner side of the curved section during shield construction of small radius curved tunnels, and the disturbance to the ground surface and mechanical properties of surrounding rock and segment are more severe. This paper establishes the numerical models of small radius curve tunnels and straight tunnels to study the characteristics of surface deformation caused by the shield excavation of small radius curved tunnels and the influence of shield construction parameters on ground settlement, surrounding rock deformation, and segment force. The maximum error between the numerical simulation results and the measured surface settlement curve is 7.3%, which is in good agreement. The results show that: (1) The maximum value of the surface settlement of the small radius curve tunnel appears inside the curve section, and with the decrease in the curve radius, the surface settlement increases, and the distance between the peak settlement point and the tunnel center is larger. (2) When the curve radius of the tunnel is smaller, the lateral displacement of the ground surface moves farther to the inner side, and the range of soil mass with lateral displacement in the inner side is also wider. (3) Increasing the heading face pressure and grouting pressure can reduce surface settlement, but the heading face pressure should not exceed 350 kPa, and the grouting pressure should not exceed 250 kPa. (4) When the curve radius is smaller, the deformation of surrounding rock and the segment stress is larger.
Physico-Chemical Features of Undoped and Fe/Cu-Doped Na0.67MnO2-Layered Cathodes for Sodium Batteries
Authors: Ambrosetti Marco , Mozzati Maria Cristina , Cini Alberto , Fittipaldi Maria , Spada Daniele , Sturini Michela , Quinzeni Irene , Bini Marcella
Published: September 2022

Na0.67MnO2 (NMO) stands out among the layered cathode materials used for sodium batteries due to its high-capacity values, low cost, and environmental friendliness. Unfortunately, many drawbacks arise during cycling, but nanostructure tailoring and doping can help to mitigate them. Our aim was to synthesize undoped and Cu- or Fe-doped NMO samples via the sol-gel route, with a different cooling step to room temperature, i.e., in a natural way or via quenching. The formation of a mixture of polymorphs was observed, as well as differences in the external morphology of the powders’ grains. The use of spectroscopic techniques, Mössbauer spectroscopy for the Fe-doped samples and Electron paramagnetic resonance, allowed us to gain insights into the oxidation states of transition metals and to make suggestions about the magnetic ordering, as well as on the possible presence of magnetic impurities. Cyclic voltammetry and galvanostatic cycling results were interpreted on the basis of the spectroscopic data: the introduction of substituents, in general, worsens the capacity values, due to the decrease in the P2 amount and the introduction of structural distortions. The structural stability of the samples in air as a function of time was also analyzed via X-ray diffraction, demonstrating the positive effect of Cu presence.
Federated Learning for Edge Computing: A Survey
Authors: Brecko Alexander , Kajati Erik , Koziorek Jiri , Zolotova Iveta
Published: September 2022

New technologies bring opportunities to deploy AI and machine learning to the edge of the network, allowing edge devices to train simple models that can then be deployed in practice. Federated learning (FL) is a distributed machine learning technique to create a global model by learning from multiple decentralized edge clients. Although FL methods offer several advantages, including scalability and data privacy, they also introduce some risks and drawbacks in terms of computational complexity in the case of heterogeneous devices. Internet of Things (IoT) devices may have limited computing resources, poorer connection quality, or may use different operating systems. This paper provides an overview of the methods used in FL with a focus on edge devices with limited computational resources. This paper also presents FL frameworks that are currently popular and that provide communication between clients and servers. In this context, various topics are described, which include contributions and trends in the literature. This includes basic models and designs of system architecture, possibilities of application in practice, privacy and security, and resource management. Challenges related to the computational requirements of edge devices such as hardware heterogeneity, communication overload or limited resources of devices are discussed.
Trends for the Thermal Degradation of Polymeric Materials: Analysis of Available Techniques, Issues, and Opportunities
Authors: Gałko Grzegorz , Sajdak Marcin
Published: September 2022

This paper examines the degradation trends of polymeric materials during heat conversion and solvolysis processes. The presence of different fractions of polymeric materials, such as PET, PP, SBR, ABS, resin, and tier waste, necessitates the use of different procedures for degradation, transformation, and further elimination from the natural environment. A significant part of the work was devoted to discussing the issue of thermal pyrolysis, taking into account the chemical composition and the possible impact of the process reaction mechanism, the type of raw material used, and the influence of the process temperature on the yields of low, medium, and high boiling products. The issue was extended to the possibility of decomposition of polymers based on the use of catalytic additives for the improvement and efficiency of the process and the structural modification of reactors. The major goal of this investigation of these various options was to generate a spectrum of accessible strategies for polymeric material degradation. The optimal technique depends on the polymer type and predicted final product qualities. Different catalysts, such as ZSM-5 (Zeolite Socony Mobil-5 one of the most efficient catalysts), ZSM-5 with ammonium groups, and ZSM-5 with 10% Ni, improved the efficiency of several heating processes. The final products after polymeric material degradation were determined by the type and conditions of the degradation processes, results of the materials characterisation, and the scale of the reactors utilised.
Correction of Point Load Strength on Irregular Carbonaceous Slate in the Luang Prabang Suture Zone and the Prediction of Uniaxial Compressive Strength
Authors: Wang Jianjun , Yang Yang , Tan Zhongsheng , Li Dongfeng , Liu Qianli
Published: September 2022

Uniaxial compressive strength (UCS) testing requires high-quality core samples, which is a difficult task for weak, highly fractured, thinly bedded, foliated, and weathered rocks. In addition, it is time-consuming and expensive. Because of the good relationship between rock point load strength (PLS) and UCS, the PLS could be used to estimate rock UCS quickly. The lump structure and layer structure of carbonaceous slate are revealed in the tunnels of the China–Laos Railway in the Laos Luang Prabang Suture Zone as one of the important factors leading to tunnel squeezing deformation and support structures. To reveal the relationship between the PLS and UCS of carbonaceous slate in the Luang Prabang Suture Zone, PLS tests and UCS tests of lump-structure carbonaceous slate (lamina plane inconspicuous) and layer-structure carbonaceous slate (lamina plane conspicuous) were performed. Results show that the Is(50) of lump-structure carbonaceous slate ranged from 0.06 MPa to 0.30 Mpa, the Is(50) of layer-structure carbonaceous slates which were loaded perpendicular to the lamina plane ranged from 0.64 MPa to 1.25 MPa, the Is(50) of layer-structure carbonaceous slates which were loaded parallel to the lamina plane ranged from 0.49 MPa to 0.71 MPa, and the correction power index m ranged from 0.42 to 0.51 with an average value of 0.47. Four correlation expressions of carbonaceous slate relationships between PLS and UCS were fitted by zero-intercept linear expression, nonzero intercept linear expression, power expression, and logarithmic expression, and the calculation results were compared with results calculated by the International Society of Rock Mechanics (ISRM) correlation equation. It is concluded that the correlation equation between UCS and PLS recommended by ISRM specifications easily causes soft rock strength overestimation, which affects the correct evaluation of the surrounding rock property and the structural design safety of tunnels and underground projects. The zero-intercept linear equation UCS = 18.45Is(50) has better goodness of fit and higher accuracy in predicting the UCS of the carbonaceous slate in the Luang Prabang Suture Zone.
A Deep Learning Micro-Scale Model to Estimate the CO2 Emissions from Light-Duty Diesel Trucks Based on Real-World Driving
Authors: Zhang Rongshuo , Wang Yange , Pang Yujie , Zhang Bowen , Wei Yangbing , Wang Menglei , Zhu Rencheng
Published: September 2022

On-road carbon dioxide (CO2) emissions from light-duty diesel trucks (LDDTs) are greatly affected by driving conditions, which may be better predicted with the sequence deep learning model as compared to traditional models. In this study, two typical LDDTs were selected to investigate the on-road CO2 emission characteristics with a portable emission measurement system (PEMS) and a global position system (GPS). A deep learning-based LDDT CO2 emission model (DL-DTCEM) was developed based on the long short-term memory network (LSTM) and trained by the measured data with the PEMS. Results show that the vehicle speed, acceleration, VSP, and road slope had obvious impacts on the transient CO2 emission rates. There was a rough positive correlation between the vehicle speed, road slope, and CO2 emission rates. The CO2 emission rate increased significantly when the speed was >5 m/s, especially at high acceleration. The correlation coefficient (R2) and the root mean square error (RMSE) between the monitored CO2 emissions with PEMS and the predicted values with the DL-DTCEM were 0.986–0.990 and 0.165–0.167, respectively. The results proved that the model proposed in this study can predict very well the on-road CO2 emissions from LDDTs.
Estimation of Potential Evapotranspiration in the Yellow River Basin Using Machine Learning Models
Authors: Liu Jie , Yu Kunxia , Li Peng , Jia Lu , Zhang Xiaoming , Yang Zhi , Zhao Yang
Published: September 2022

Potential evapotranspiration (PET) is an important input variable of many ecohydrological models, but commonly used empirical models usually input numerous meteorological factors. In consideration of machine learning for complex nonlinear learning, we evaluated the applicability of three machine learning algorithms in PET estimation in the Yellow River basin (YRB), in addition to determining significant factors affecting the accuracy of machine learning. Furthermore, the importance of meteorological factors at varying altitudes and drought index grades for PET simulation were evaluated. The results show that the accuracy of PET simulation in the YRB depends on the input of various meteorological factors; however, machine learning models including average temperature (Tmean) and sunshine hours (n) as input achieved satisfactory accuracy in the absence of complete meteorological data. Random forest generally performed best among all investigated models, followed by extreme learning machine, whereas empirical models overestimated or underestimated PET. The importance index shows that Tmean is the most influential factor with respect to PET, followed by n, and the influence of Tmean on PET gradually decreased with increased altitude and drier climate, whereas the influence of n shows the opposite trend.
Kinetic Studies on the Steam Gasification of Chars Derived from Coals by Different Isoconversional Methods
Authors: An Mei , Guo Qingjie
Published: September 2022

Previous studies have successfully assessed the extent to which a kinetic model accurately represents a specific reaction mechanism by comparing the kinetic parameters derived from the kinetic model to those obtained using isoconversional methods. However, this approach remains underdeveloped for the important steam gasification reaction of char. This study addresses this issue by conducting a series of steam-assisted char gasification tests, using thermogravimetric analysis at five different heating rates. The results indicate that the carbon conversion ratio of the char gasification reaction increases with the increasing heating rate. The activation energies of the reaction process are determined with different carbon conversion ratios using three isoconversional methods, including the Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, and Starink methods. The gasification mechanism is also analyzed using model-fitting methods with a wide variety of carbon conversion models, and the accuracies of the models are evaluated, firstly, by comparing the obtained goodness of fit values of the models with the experimental results, and, secondly, by comparing the obtained activation energies with those derived using the isoconversional methods. The goodness of fit results and the results of the comparisons between the activation energies obtained using the various models with the isoconversional values demonstrate that the three-dimensional Avrami–Erofeev model best represents the steam gasification char reaction, where the difference between the two activation energy values is only 0.70 KJ.mol−1. The reliability of the proposed approach for evaluating the applicability of a given kinetic model to the steam gasification reaction of char is tested by comparing the results obtained for char samples derived from three different bituminous coal sources.
Biomass Carbon Materials Contribute Better Alkali-Metal–Selenium Batteries: A Mini-Review
Authors: Du Yixun , Ma Shuang , Dai Jinhang , Lin Juan , Zhou Xia , Chen Tiezhu , Gu Xingxing
Published: September 2022

Owing to the sustainability, environmental friendliness, and structural diversity of biomass-derived materials, extensive efforts have been devoted to using them in high-energy rechargeable batteries. Alkali-metal–selenium batteries, one of the high-energy rechargeable batteries with a reasonable cost compared to up-to-date lithium-ion batteries, have also attracted significant attention. Therefore, a timely and comprehensive review of the biomass carbon structures/components to the mechanisms for enhancing alkali-metal–selenium batteries has been systematically introduced. In the end, advantages, challenges, and outlooks are pointed out for the future development of biomass-derived carbon materials in alkali-metal–selenium batteries. This review could help researchers think about using biomass carbon materials to improve battery performance and what other problems should be solved, thereby promoting the application of biomass materials in battery design.
Kinetics and Mechanisms of Saccharomyces boulardii Release from Optimized Whey Protein–Agavin–Alginate Beads under Simulated Gastrointestinal Conditions
Authors: Chávez-Falcón María Sady , Buitrago-Arias Carolina , Avila-Reyes Sandra Victoria , Solorza-Feria Javier , Arenas-Ocampo Martha Lucía , Camacho-Díaz Brenda Hildeliza , Jiménez-Aparicio Antonio Ruperto
Published: September 2022

Encapsulation is a process in which a base material is encapsulated in a wall material that can protect it against external factors and/or improve its bioavailability. Among the different encapsulation techniques, ionic gelation stands out as being useful for thermolabile compounds. The aim of this work was to encapsulate Saccharomyces boulardii by ionic gelation using agavins (A) and whey protein (WP) as wall materials and to evaluate the morphostructural changes that occur during in vitro gastrointestinal digestion. Encapsulations at different levels of A and WP were analyzed using microscopic, spectroscopic and thermal techniques. Encapsulation efficiency and cell viability were evaluated. S. boulardii encapsulated at 5% A: 3.75% WP (AWB6) showed 88.5% cell survival after the simulated gastrointestinal digestion; the bead showed a significantly different microstructure from the controls. The mixture of A and WP increased in the survival of S. boulardii respect to those encapsulated with alginate, A or WP alone. The binary material mixture simultaneously allowed a controlled release of S. boulardii by mostly diffusive Fickian mechanisms and swelling. The cell-release time was found to control the increment of the Damköhler number when A and WP were substrates for S. boulardii, in this way allowing greater protection against gastrointestinal conditions.
Adiabatic Invariant of Center-of-Mass Motion during Walking as a Dynamical Stability Constraint on Stride Interval Variability and Predictability
Authors: Buisseret Fabien , Dehouck Victor , Boulanger Nicolas , Henry Guillaume , Piccinin Florence , White Olivier , Dierick Frédéric
Published: September 2022

Human walking exhibits properties of global stability, and local dynamic variability, predictability, and complexity. Global stability is typically assessed by quantifying the whole-body center-of-mass motion while local dynamic variability, predictability, and complexity are assessed using the stride interval. Recent arguments from general mechanics suggest that the global stability of gait can be assessed with adiabatic invariants, i.e., quantities that remain approximately constant, even under slow external changes. Twenty-five young healthy participants walked for 10 min at a comfortable pace, with and without a metronome indicating preferred step frequency. Stride interval variability was assessed by computing the coefficient of variation, predictability using the Hurst exponent, and complexity via the fractal dimension and sample entropy. Global stability of gait was assessed using the adiabatic invariant computed from averaged kinetic energy value related to whole-body center-of-mass vertical displacement. We show that the metronome alters the stride interval variability and predictability, from autocorrelated dynamics to almost random dynamics. However, despite these large local variability and predictability changes, the adiabatic invariant is preserved in both conditions, showing the global stability of gait. Thus, the adiabatic invariant theory reveals dynamical global stability constraints that are “hidden” behind apparent local walking variability and predictability.
Diversity and Assemblage of Harmful Algae in Homestead Fish Ponds in a Tropical Coastal Area
Authors: Akter Liza , Ullah Md. Akram , Hossain Mohammad Belal , Karmaker Anu Rani , Hossain Md. Solaiman , Albeshr Mohammed Fahad , Arai Takaomi
Published: September 2022

Algae are the naturally produced food for fish in any aquatic ecosystem and an indicator of a productive pond. However, excess abundance of harmful algae can have detrimental effects on fish health. In this study, the algal communities of 30 coastal homestead fish ponds were investigated to identify the diversity, assemblage and controlling environmental variables of harmful algae from a tropical coastal area. The findings showed that 81 of the 89 genera of identified algae were harmful, with the majority of them being in the classes of Cyanophyceae (50.81%), Chlorophyceae (23.75%), Bacillariophyceae (9.5%), and Euglenophyceae (8.47%). Microcystis spp. alone contributed 28.24% to the total abundance of harmful algae. Significant differences (p < 0.05) in algal abundance were found among the ponds with the highest abundance (470 ± 141.74 × 103 cells L−1) at pond (S25) near agricultural fields and the lowest abundance (109.33 ± 46.91 × 103 cells L−1) at pond (S14) which was lacking sufficient sunlight and nutrients. Diversity indices, e.g., dominance (D), evenness (J′), richness (d) and Shannon diversity index (H′) ranged from 0.17 to 0.44, 0.23 to 0.6, 0.35 to 2.23 and 0.7 to 1.79, respectively, indicating a moderate range of diversity and community stability. Community composition analysis showed the assemblage was dominated by Cyanophyceae, Chlorophyceae and Bacillariophyceae, whereas, multivariate cluster analyses (CA) identified 11 major clusters. To identify the factors controlling their distribution or community assemblages, eight environmental variables (temperature, pH, dissolved oxygen (DO), salinity, transparency, nitrates, phosphates and sulphate) were measured. ANOVA analysis showed that the variables significantly differed (p < 0.05) among the ponds, and canonical correspondence analysis (CCA) demonstrated that DO, nitrates, phosphates, sulphates, salinity and transparency have the most impact on the abundance of algal genera. In addition, analyses with Pearson’s correlation coefficient showed that the abundance of total algae, diversity and community were mainly governed by phosphates and sulphates. These results can be used to identify and control these toxic algal groups in the local aquaculture sector.
Suppression of Glucocorticoid Response in Stressed Mice Using 50 Hz Electric Field According to Immobilization Degree and Posture
Authors: Harakawa Shinji , Hori Takuya , Hiramoto Takao , Nedachi Takaki , Shinba Toshikazu , Suzuki Hiroshi
Published: September 2022

Various studies on immobilized BALB/c mice to evaluate changes in hormone levels associated with stress responses have advanced the characterization of multiple aspects of the biological actions of extremely low-frequency (ELF) electric fields (EFs). In this study, we aimed to investigate the effect of mouse posture on its stress responses and evaluate the importance of adjusting the stress degree in the model. Mice were immobilized inside centrifuge tubes and exposed to an ELF EF generated between parallel plate electrodes. Blood was collected under anesthesia immediately after EF exposure, and plasma glucocorticoids were assayed. The inhibitory effects of EFs on glucocorticoid elevation by immobilization were reproduced regardless whether mice were in the abdominal or lateral recumbent position, for the EF vector delivered to mice through the sagittal or frontal plane. The effect of ELF EF was reproduced in moderately and mildly stressed mice but not in severely immobilized mice. Hence, adjusting the stress degree is critical to the reproducibility of the results for this model. We characterized the effects of ELF EF on homeostasis, including the stress response, and provided valuable information for the scientific evaluation of the biological risks and medical applications of ELF EF.
Phosphatidylethanolamine N-Methyltransferase Knockout Modulates Metabolic Changes in Aging Mice
Authors: Zhou Qishun , Zhang Fangrong , Kerbl-Knapp Jakob , Korbelius Melanie , Kuentzel Katharina Barbara , Vujić Nemanja , Akhmetshina Alena , Hörl Gerd , Paar Margret , Steyrer Ernst , Kratky Dagmar , Madl Tobias
Published: September 2022

Phospholipid metabolism, including phosphatidylcholine (PC) biosynthesis, is crucial for various biological functions and is associated with longevity. Phosphatidylethanolamine N-methyltransferase (PEMT) is a protein that catalyzes the biosynthesis of PC, the levels of which change in various organs such as the brain and kidneys during aging. However, the role of PEMT for systemic PC supply is not fully understood. To address how PEMT affects aging-associated energy metabolism in tissues responsible for nutrient absorption, lipid storage, and energy consumption, we employed NMR-based metabolomics to study the liver, plasma, intestine (duodenum, jejunum, and ileum), brown/white adipose tissues (BAT and WAT), and skeletal muscle of young (9–10 weeks) and old (91–132 weeks) wild-type (WT) and PEMT knockout (KO) mice. We found that the effect of PEMT-knockout was tissue-specific and age-dependent. A deficiency of PEMT affected the metabolome of all tissues examined, among which the metabolome of BAT from both young and aged KO mice was dramatically changed in comparison to the WT mice, whereas the metabolome of the jejunum was only slightly affected. As for aging, the absence of PEMT increased the divergence of the metabolome during the aging of the liver, WAT, duodenum, and ileum and decreased the impact on skeletal muscle. Overall, our results suggest that PEMT plays a previously underexplored, critical role in both aging and energy metabolism.
DNA Methylation in Regulatory T Cell Differentiation and Function: Challenges and Opportunities
Authors: Bai Lu , Hao Xiaolei , Keith Julia , Feng Yongqiang
Published: September 2022

As a bona fide epigenetic marker, DNA methylation has been linked to the differentiation and function of regulatory T (Treg) cells, a subset of CD4 T cells that play an essential role in maintaining immune homeostasis and suppressing autoimmunity and antitumor immune response. DNA methylation undergoes dynamic regulation involving maintenance of preexisting patterns, passive and active demethylation, and de novo methylation. Scattered evidence suggests that these processes control different stages of Treg cell lifespan ranging from lineage induction to cell fate maintenance, suppression of effector T cells and innate immune cells, and transdifferentiation. Despite significant progress, it remains to be fully explored how differential DNA methylation regulates Treg cell fate and immunological function. Here, we review recent progress and discuss the questions and challenges for further understanding the immunological roles and mechanisms of dynamic DNA methylation in controlling Treg cell differentiation and function. We also explore the opportunities that these processes offer to manipulate Treg cell suppressive function for therapeutic purposes by targeting DNA methylation.
In Silico Maturation of a Nanomolar Antibody against the Human CXCR2
Authors: Buratto Damiano , Wan Yue , Shi Xiaojie , Yang Guang , Zonta Francesco
Published: September 2022

The steady increase in computational power in the last 50 years is opening unprecedented opportunities in biology, as computer simulations of biological systems have become more accessible and can reproduce experimental results more accurately. Here, we wanted to test the ability of computer simulations to replace experiments in the limited but practically useful scope of improving the biochemical characteristics of the abN48 antibody, a nanomolar antagonist of the CXC chemokine receptor 2 (CXCR2) that was initially selected from a combinatorial antibody library. Our results showed a good correlation between the computed binding energies of the antibody to the peptide target and the experimental binding affinities. Moreover, we showed that it is possible to design new antibody sequences in silico with a higher affinity to the desired target using a Monte Carlo Metropolis algorithm. The newly designed sequences had an affinity comparable to the best ones obtained using in vitro affinity maturation and could be obtained within a similar timeframe. The methodology proposed here could represent a valid alternative for improving antibodies in cases in which experiments are too expensive or technically tricky and could open an opportunity for designing antibodies for targets that have been elusive so far.
Galectokines: The Promiscuous Relationship between Galectins and Cytokines
Authors: Sanjurjo Lucía , Broekhuizen Esmee C. , Koenen Rory R. , Thijssen Victor L. J. L.
Published: September 2022

Galectins, a family of glycan-binding proteins, are well-known for their role in shaping the immune microenvironment. They can directly affect the activity and survival of different immune cell subtypes. Recent evidence suggests that galectins also indirectly affect the immune response by binding to members of another immunoregulatory protein family, i.e., cytokines. Such galectin-cytokine heterodimers, here referred to as galectokines, add a new layer of complexity to the regulation of immune homeostasis. Here, we summarize the current knowledge with regard to galectokine formation and function. We describe the known and potential mechanisms by which galectokines can help to shape the immune microenvironment. Finally, the outstanding questions and challenges for future research regarding the role of galectokines in immunomodulation are discussed.
Kinetic Interjoint Coordination in Lower Limbs during Gait in Patients with Hemiparesis
Authors: Sekiguchi Yusuke , Owaki Dai , Honda Keita , Izumi Shin-Ichi
Published: September 2022

The coordination of joint moments in the same limb—otherwise known as kinetic interjoint coordination—during gait in patients with hemiparesis remains unclear. This study clarifies the characteristics of kinetic interjoint coordination in the lower limbs using a principal component analysis (PCA). Using a three-dimensional motion analysis system and force plates, the kinematic and kinetic data from 29 patients with hemiparesis and 12 healthy controls were measured when they walked along a 7 m walkway. The spatiotemporal principal components (PCs) of the hip, knee, and ankle joint moments were calculated using a PCA and the motor modules during gait were identified. We adopted a case–control study design to clarify the kinetic interjoint coordination characteristics during gait in patients with hemiplegia. As the results of comparisons between the patients and controls showed, the peak timing of the first PC, which had high loadings of hip and ankle joint moments on the paretic side, was significantly earlier than that on the other sides. The loading of the knee joint moment for the first PC on the paretic side was significantly lower than that on the non-paretic side (p < 0.05), which was highly variable with negative and positive values. The results demonstrated that the first motor module comprising hip and ankle joint moments on the paretic side during gait in patients with hemiparesis may be merged with knee joint flexion or the extension moment, and may have an atypical temporal component. The index of kinetic interjoint coordination would be a useful tool for robotic-based systems for effective rehabilitation, which would significantly contribute to the acceleration of collaborative research in the fields of engineering and rehabilitation medicine.
Platelets’ Nanomechanics and Morphology in Neurodegenerative Pathologies
Authors: Strijkova Velichka , Todinova Svetla , Andreeva Tonya , Langari Ariana , Bogdanova Desislava , Zlatareva Elena , Kalaydzhiev Nikolay , Milanov Ivan , Taneva Stefka G.
Published: September 2022

The imaging and force–distance curve modes of atomic force microscopy (AFM) are explored to compare the morphological and mechanical signatures of platelets from patients diagnosed with classical neurodegenerative diseases (NDDs) and healthy individuals. Our data demonstrate the potential of AFM to distinguish between the three NDDs—Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and Alzheimer’s disease (AD), and normal healthy platelets. The common features of platelets in the three pathologies are reduced membrane surface roughness, area and height, and enhanced nanomechanics in comparison with healthy cells. These changes might be related to general phenomena associated with reorganization in the platelet membrane morphology and cytoskeleton, a key factor for all platelets’ functions. Importantly, the platelets’ signatures are modified to a different extent in the three pathologies, most significant in ALS, less pronounced in PD and the least in AD platelets, which shows the specificity associated with each pathology. Moreover, different degree of activation, distinct pseudopodia and nanocluster formation characterize ALS, PD and AD platelets. The strongest alterations in the biophysical properties correlate with the highest activation of ALS platelets, which reflect the most significant changes in their nanoarchitecture. The specific platelet signatures that mark each of the studied pathologies can be added as novel biomarkers to the currently used diagnostic tools.
Anti-Cancer Activity of the Combinational Treatment of Noozone Cold Plasma with p-FAK Antibody-Conjugated Gold Nanoparticles in OSCC Xenograft Mice
Authors: Choi Jeong-Hae , Gu Hee-Jin , Park Kwang-Ha , Hwang Dae-Seok , Kim Gyoo-Cheon
Published: September 2022

Oral squamous cell cancer (OSCC) is the most common type of oral cancer (about 80–90% of cases) and various research is being done to cure the disease. This paper aims to verify whether treatment with no-ozone cold plasma (NCP), which is designed for safe usage of the plasma on oral cavities, in combination with gold nanoparticles conjugated with p-FAK antibody (p-FAK/GNP) can trigger the selective and instant killing of SCC-25 cells both in vitro and in vivo. When SCC25 and HaCaT cells are exposed to p-FAK/GNP+NCP, the instant cell death was observed only in SCC25 cells. Such p-FAK/GNP+NCP-mediated cell death was observed only when NCP was directly treated on SCC25 harboring p-FAK/GNP. During NCP treatment, the removal of charged particles from NCP using grounded electric mesh radically decreased the p-FAK/GNP+NCP-mediated cell death. This p-FAK/GNP+NCP-mediated selective cell death of OSCC was also observed in mice xenograft models using SCC25 cells. The mere treatment of p-FAK/GNP and NCP on the xenograft tumor slowly decreased the size of the tumor, and only about 50% of the tumor remained at the end of the experiment. On the other hand, 1 week of p-FAK/GNP+NCP treatment was enough to reduce half of the tumor size, and most of tumor tissue had vanished at the end. An analysis of isolated tissues showed that in the case of individual treatment with p-FAK/GNP or NCP, the cancer cell population was reduced due to apoptotic cell death. However, in the case of p-FAK/GNP+NCP, apoptotic cell death was unobserved, and most tissues were composed of collagen. Thus, this paper suggests the possibility of p-FAK/GNP+NCP as a new method for treating OSCC.
Conjugated Polymers-Based Biosensors for Virus Detection: Lessons from COVID-19
Authors: Tran Vinh Van
Published: September 2022

Human beings continue to endure the coronavirus disease (COVID-19) pandemic, which has spread throughout the world and significantly affected all countries and territories, causing a socioeconomic crunch. Human pathogenic viruses are considered a global burden for public health, both in the present and the future. Therefore, the early and accurate diagnosis of viruses has been and still is critical and should be accorded a degree of priority that is equivalent to vaccinations and drugs. We have opened a Special Issue titled “Conjugated polymers-based biosensors for virus detection”. This editorial seeks to emphasize the importance and potential of conjugated polymers in the design and development of biosensors. Furthermore, we briefly provide an overview, scientific evidence, and opinions on promising strategies for the development of CP-based electrochemical biosensors for virus detection.
Unraveling the Secrets of Colistin Resistance with Label-Free Raman Spectroscopy
Authors: Saikia Dimple , Jadhav Priyanka , Hole Arti R. , Krishna Chilakapati Murali , Singh Surya P.
Published: September 2022

The rise in number of infections from multidrug-resistant (MDR) Gram-negative microbes has led to an increase in the use of a variety of ‘polymyxins’ such as colistin. Even though colistin is known to cause minor nephro- and neuro-toxicity, it is still considered as last resort antibiotic for treating MDR infections. In this study, we have applied Raman spectroscopy to understand the differences among colistin sensitive and resistant bacterial strains at community level. We have successfully generated colistin resistant clones and verified the presence of resistance-causing MCR-1 plasmid. A unique spectral profile associated with specific drug concentration has been obtained. Successful delineation between resistant and sensitive cells has also been achieved via principal component analysis. Overall findings support the prospective utility of Raman spectroscopy in identifying anti-microbial resistance.
Chick Provisioning in Grey-Faced Petrel (Pterodroma gouldi) under Environmental Stress
Authors: Russell James C. , Welch Jemma R. , Dunn Rob , Bourgeois Karen
Published: September 2022

Grey-faced Petrels (Pterodroma gouldi) are colonial burrowing seabirds predominantly nesting on offshore islands of the upper North Island of New Zealand. We studied their chick provisioning on Te Hāwere-a-Maki during two years of unfavourable warmer La Niña conditions in 2011 and 2013. We intensively monitored chicks in each year, weighing chicks every 12 h for 10 consecutive days to estimate meal sizes following chick provisioning and to estimate 12-hourly body mass loss as a function of time since last feeding. We found a quadratic relationship of body mass loss with time since last feeding, with rapid digestion of meals following provisioning followed by a period of fasting from five days post feeding as chicks waited an unknown and variable amount of time until their next meal. The rate of body mass loss did not depend on chick age nor body mass, and did not differ between years, but heavier chicks included in our study were more likely to successfully fledge, suggesting a legacy of adult provisioning prior to our study commencing. Our regular handling of chicks for monitoring has no discernible impact on parent provisioning compared to a set of control chicks. The mean estimates of 100-gram meal sizes and 10-day foraging trip durations are likely to be below the break-even point for this species.