The 2023 MDPI Annual Report has
been released!
 
16 pages, 5538 KiB  
Article
Development of Integrated Control for Verticillium Wilt of Smoke Trees in Beijing
by Bimeng Li, Ruifeng Guo, Yize Zhao, Qiyan Li, Lizhou Song, Chong Shen, Chenming Du, Yuntao Gu, Guanghang Qiao, Liping Wang, Fei Yuan, Sanxiang Huang and Yonglin Wang
Forests 2024, 15(5), 776; https://doi.org/10.3390/f15050776 (registering DOI) - 28 Apr 2024
Abstract
Smoke tree (Cotinus coggygria) is an important ornamental tree that represents the autumnal landscape of red leaves in Northern China, especially in Beijing. However, Verticillium wilt, caused by the fungus (Verticillium dahliae), has resulted in a high mortality rate [...] Read more.
Smoke tree (Cotinus coggygria) is an important ornamental tree that represents the autumnal landscape of red leaves in Northern China, especially in Beijing. However, Verticillium wilt, caused by the fungus (Verticillium dahliae), has resulted in a high mortality rate for smoke trees, posing a serious threat to the highly valued landscape of red leaves in Beijing. To explore an efficient control measure for Verticillium wilt, we systematically analyzed the applicability and efficacy of multiple treatments for three consecutive years in Xiangshan Park and Badaling Forest Park. From 2021 to 2023, diseased smoke trees in Xiangshan Park were subjected to three application methods (agent irrigation, trunk injection, or a combination of the two) and five candidate agents, namely Bacillus subtilis, azoxystrobin, propiconazole, carbendazim, and prochloraz. Analyses of the data for three consecutive years revealed a decreasing trend in the annual disease incidence rate. Specifically, the combined application of agent irrigation and trunk injection exhibited the highest control effect and a significant improvement in the landscape of red leaves in Beijing. Furthermore, the combination of propiconazole via irrigation plus the trunk injection of carbendazim and prochloraz had the greatest control effect. These suppressive measurements were further used and demonstrated to be effective in Badaling Forest Park. Overall, our study provides an effective disease management means for controlling Verticillium wilt in smoke trees. Full article
(This article belongs to the Special Issue Management of Forest Pests and Diseases II)
15 pages, 3964 KiB  
Article
Integrative Genomics and Bioactivity-Guided Isolation of Novel Antimicrobial Compounds from Streptomyces sp. KN37 in Agricultural Applications
by Jing Zhao, Qinghua Li, Muhammad Zeeshan, Guoqiang Zhang, Chunjuan Wang, Xiaoqiang Han and Desong Yang
Molecules 2024, 29(9), 2040; https://doi.org/10.3390/molecules29092040 (registering DOI) - 28 Apr 2024
Abstract
Actinomycetes have long been recognized as an important source of antibacterial natural products. In recent years, actinomycetes in extreme environments have become one of the main research directions. Streptomyces sp. KN37 was isolated from the cold region of Kanas in Xinjiang. It demonstrated [...] Read more.
Actinomycetes have long been recognized as an important source of antibacterial natural products. In recent years, actinomycetes in extreme environments have become one of the main research directions. Streptomyces sp. KN37 was isolated from the cold region of Kanas in Xinjiang. It demonstrated potent antimicrobial activity, but the primary active compounds remained unclear. Therefore, we aimed to combine genomics with traditional isolation methods to obtain bioactive compounds from the strain KN37. Whole-genome sequencing and KEGG enrichment analysis indicated that KN37 possesses the potential for synthesizing secondary metabolites, and 41 biosynthetic gene clusters were predicted, some of which showed high similarity to known gene clusters responsible for the biosynthesis of antimicrobial antibiotics. The traditional isolation methods and activity-guided fractionation were employed to isolate and purify seven compounds with strong bioactivity from the fermentation broth of the strain KN37. These compounds were identified as 4-(Diethylamino)salicylaldehyde (1), 4-Nitrosodiphenylamine (2), N-(2,4-Dimethylphenyl)formamide (3), 4-Nitrocatechol (4), Methylsuccinic acid (5), Phenyllactic acid (6) and 5,6-Dimethylbenzimidazole (7). Moreover, 4-(Diethylamino)salicylaldehyde exhibited the most potent inhibitory effect against Rhizoctonia solani, with an EC50 value of 14.487 mg/L, while 4-Nitrosodiphenylamine showed great antibacterial activity against Erwinia amylovora, with an EC50 value of 5.715 mg/L. This study successfully isolated several highly active antimicrobial compounds from the metabolites of the strain KN37, which could contribute as scaffolds for subsequent chemical synthesis. On the other hand, the newly predicted antibiotic-like substances have not yet been isolated, but they still hold significant research value. They are instructive in the study of active natural product biosynthetic pathways, activation of silent gene clusters, and engineering bacteria construction. Full article
24 pages, 3154 KiB  
Article
Tourist Tracking Techniques and Their Role in Destination Management: A Bibliometric Study, 2007–2023
by Yarlein Ivama Julio Guerrero and Francisco Teixeira Pinto Dias
Sustainability 2024, 16(9), 3708; https://doi.org/10.3390/su16093708 (registering DOI) - 28 Apr 2024
Abstract
The tourism industry has recently undergone a significant evolution because of the implementation of Information and Communication Technologies (ICT). These changes have raised new conceptions of destinations, thus giving rise to smart destinations. In this context, digital tracking of tourists has become of [...] Read more.
The tourism industry has recently undergone a significant evolution because of the implementation of Information and Communication Technologies (ICT). These changes have raised new conceptions of destinations, thus giving rise to smart destinations. In this context, digital tracking of tourists has become of great interest. This article aims to analyze the research landscape on tourist tracking through a bibliometric study, which allows the evaluation of the performance of publications, recognition of the prominent SciVal topics, analysis of the evolution of the techniques, and recognition of their use as a tool that contributes to the development of smart destinations. Unlike prior studies in this area, in addition to the performance analysis of publications, this paper focuses only on empirical studies on tourist tracking, identifies the prominent SciVal topics, and analyzes the linkage thereof with the Sustainable Development Goals (SDGs). The bibliometric study was carried out based on articles on tourist tracking extracted from the Scopus database and published between 2007 and 2023. This research is mainly quantitative, based on research performance analysis (journals, authors, institutions, and countries) and science mapping (citation analysis, co-word analysis, co-authorship analysis). Results show the quality of the publications made in the 2007–2023 period and indicate that the most used techniques have been GPS devices, social media, and app-based GPS/GNSS. In addition, it was found that the evolution of the techniques occurred at the same time as the development of ICT and that the prominent SciVal topic that covers the largest number of publications is associated with destination management. It is concluded that the application of tourist tracking techniques contributes to the transformation of destinations into smart destinations, as they provide useful relevant information to tourism market stakeholders for the development of strategies that improve decision-making and allow for the sustainable management of destinations. Full article
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11 pages, 794 KiB  
Article
Synthesis of Flavonols and Assessment of Their Biological Activity as Anticancer Agents
by Yu-Hui Hsieh, Pei-Hsuan Hsu, Anren Hu, Yang-Je Cheng, Tzenge-Lien Shih and Jih-Jung Chen
Molecules 2024, 29(9), 2041; https://doi.org/10.3390/molecules29092041 (registering DOI) - 28 Apr 2024
Abstract
A series of flavanols were synthesized to assess their biological activity against human non-small cell lung cancer cells (A549). Among the sixteen synthesized compounds, it was observed that compounds 6k (3.14 ± 0.29 µM) and 6l (0.46 ± 0.02 µM) exhibited higher potency [...] Read more.
A series of flavanols were synthesized to assess their biological activity against human non-small cell lung cancer cells (A549). Among the sixteen synthesized compounds, it was observed that compounds 6k (3.14 ± 0.29 µM) and 6l (0.46 ± 0.02 µM) exhibited higher potency compared to 5-fluorouracil (5-Fu, 4.98 ± 0.41 µM), a clinical anticancer drug which was used as a positive control. Moreover, compound 6l (4’-bromoflavonol) markedly induced apoptosis of A549 cells through the mitochondrial- and caspase-3-dependent pathways. Consequently, compound 6l might be developed as a candidate for treating or preventing lung cancer. Full article
20 pages, 3684 KiB  
Article
Urban Physical Environments Promoting Active Leisure Travel: An Empirical Study Using Crowdsourced GPS Tracks and Geographic Big Data from Multiple Sources
by Yunwen Chen, Binhui Wang, Jing Huang, Hei Gao and Xianfan Shu
Land 2024, 13(5), 589; https://doi.org/10.3390/land13050589 (registering DOI) - 28 Apr 2024
Abstract
Specific environmental characteristics can encourage active leisure travel and increase physical activity. However, existing environment-travel studies tend to ignore the differences in environmental characteristics associated with route choice and travel distance, of which the latter could be more important for health benefits, since [...] Read more.
Specific environmental characteristics can encourage active leisure travel and increase physical activity. However, existing environment-travel studies tend to ignore the differences in environmental characteristics associated with route choice and travel distance, of which the latter could be more important for health benefits, since longer trips are associated with increased exercise. Additionally, the most recent studies focus on leisure walking and leisure cycling, and activities such as hiking, climbing, and running are examined less frequently. This study, therefore, compares the similarities and differences of the environmental factors associated with route selection and travel distance through non-parametric tests and Cox proportional hazard models. The results show that two intersecting sets of environmental elements relate to both the route chosen and the distance traveled. Land use diversity and varied topography are appealing for both leisure trips and trip length. In addition, the differences in environmental characteristics among specific leisure travels may be attributed to variations in physical activity requirements, preferences for landscape viewing, and/or sensitivity to crowding. Therefore, conclusions drawn without considering the different types of leisure travel could be skewed. Whether particular surroundings may effectively increase physical activity remains uncertain. A more holistic perspective could be beneficial when studying the connection between the environment, active travel, and health. Full article
19 pages, 3825 KiB  
Article
Sustainable Time-Dependent Cheapest Path Problem with Integrated Collaborative Stakeholders’ Perspectives
by Ivana Semanjski and Sidharta Gautama
Sustainability 2024, 16(9), 3706; https://doi.org/10.3390/su16093706 (registering DOI) - 28 Apr 2024
Abstract
The Sustainable Time-Dependent Cheapest Path Problem (STDCPP) entails locating a Hamiltonian path that covers all of the graph’s vertices at the lowest possible total sustainability cost. The issue is inspired by actual city logistics, where it is important to consider the opinions of [...] Read more.
The Sustainable Time-Dependent Cheapest Path Problem (STDCPP) entails locating a Hamiltonian path that covers all of the graph’s vertices at the lowest possible total sustainability cost. The issue is inspired by actual city logistics, where it is important to consider the opinions of diverse stakeholders in the light of sustainable urban mobility plans and service viability. To address this issue, this paper suggests a twofold contribution. First, we describe the Sustainable Time-Dependent Cheapest Path Problem and define the complex cost function, which, based on the multi-criteria decision-making approach, integrates the views of different stakeholders and sustainability elements into the route cost calculation. Second, we show that the modified problem satisfies the FIFO (First-In First-Out) property and demonstrate the applicability of the suggested approach on a real-life scenario where route sustainability is extracted from the traffic sign information system available in Flanders, Belgium. Full article
(This article belongs to the Section Sustainable Transportation)
15 pages, 1924 KiB  
Article
Antimicrobial Activity and Mechanisms of Punicalagin against Vibrio parahaemolyticus
by Hongli Liu, Wenxiu Zhu, Yue Zou and Xiaodong Xia
Foods 2024, 13(9), 1366; https://doi.org/10.3390/foods13091366 (registering DOI) - 28 Apr 2024
Abstract
This study sought to explore the antimicrobial activity of punicalagin against V. parahaemolyticus and its potential modes of action. V. parahaemolyticus ATCC 17802 and RIMD 2210633Sm were exposed to punicalagin, and the energy production, membrane potential, and envelope permeability, as well as [...] Read more.
This study sought to explore the antimicrobial activity of punicalagin against V. parahaemolyticus and its potential modes of action. V. parahaemolyticus ATCC 17802 and RIMD 2210633Sm were exposed to punicalagin, and the energy production, membrane potential, and envelope permeability, as well as the interaction with cell biomolecules, were measured using a variety of fluorescent probes combined with electrophoresis and Raman spectroscopy. Punicalagin treatment disrupted the envelope integrity and induced a decrease in intracellular ATP and pH. The uptake of 1-N-phenyl-naphtylamine (NPN) demonstrated that punicalagin weakened the outer membrane. Punicalagin damaged the cytoplasmic membrane, as indicated by the membrane depolarization and the leakage of intracellular potassium ions, proteins, and nucleic acids. Electronic microscopy observation visualized the cell damage caused by punicalagin. Further, gel electrophoresis coupled with the Raman spectrum assay revealed that punicalagin affected the protein expression of V. parahaemolyticus, and there was no effect on the integrity of genomic DNA. Therefore, the cell envelope and proteins of V. parahaemolyticus were the assailable targets of punicalagin treatment. These findings suggested that punicalagin may be promising as a natural bacteriostatic agent to control the growth of V. parahaemolyticus. Full article
19 pages, 651 KiB  
Review
Control Strategies, Economic Benefits, and Challenges of Vehicle-to-Grid Applications: Recent Trends Research
by Guangjie Chen and Zhaoyun Zhang
World Electr. Veh. J. 2024, 15(5), 190; https://doi.org/10.3390/wevj15050190 (registering DOI) - 28 Apr 2024
Abstract
With the rapid growth in the number of EVs, a huge number of EVs are connected to the power grid for charging, which places a great amount of pressure on the stable operation of the power grid. This paper focuses on the development [...] Read more.
With the rapid growth in the number of EVs, a huge number of EVs are connected to the power grid for charging, which places a great amount of pressure on the stable operation of the power grid. This paper focuses on the development of V2G applications, based on the current research status of V2G technology. Firstly, the standards on V2G applications and some pilot projects involving more representative V2G systems are introduced. Comparing V2G applications with ordered charging and unordered charging, the social and economic benefits of V2G applications are highlighted. Analysis of the social benefits of V2G applications concerns three points: the grid demand response, personalized charging, and the coordination of renewable energy sources. And analysis of the economic benefits of V2G applications is divided into three parties: the grid, the aggregator, and individuals. From the perspective of innovative EVs expanding the application scenarios through V2G technology, V2G applications for commercial EVs, emergency power applications, and vehicle-to-vehicle energy trading are introduced. The current challenges related to V2G applications are presented: users’ willingness to participate in V2G applications, battery loss, charging and discharging tariffs, privacy and security, and power loss. Finally, some research recommendations for the development of V2G applications are given and the current state of research in regard to those recommendations is presented. Full article
(This article belongs to the Special Issue Electric Vehicles and Smart Grid Interaction)
7 pages, 1202 KiB  
Case Report
Laparoscopic Management of Cesarean Scar Pregnancy with Temporary Clipping of Anterior Trunk of Hypogastric Arteries: A Case Report
by Ioana-Flavia Bacila, Ligia Balulescu, Alexandru Dabica, Simona Brasoveanu, Marilena Pirtea, Adrian Ratiu and Laurentiu Pirtea
J. Pers. Med. 2024, 14(5), 469; https://doi.org/10.3390/jpm14050469 (registering DOI) - 28 Apr 2024
Abstract
A cesarean scar ectopic pregnancy (CSP) represents an uncommon yet potentially life-threatening condition requiring immediate and efficient management. We present a case of a 32-year-old woman diagnosed with a scar pregnancy at 8 weeks of gestation. Laparoscopic surgical management was chosen due to [...] Read more.
A cesarean scar ectopic pregnancy (CSP) represents an uncommon yet potentially life-threatening condition requiring immediate and efficient management. We present a case of a 32-year-old woman diagnosed with a scar pregnancy at 8 weeks of gestation. Laparoscopic surgical management was chosen due to its minimally invasive nature and potential for preserving fertility. During the procedure, temporary clipping of uterine arteries was employed to control intraoperative bleeding. The patient recovered well postoperatively with no complications. This case highlights the feasibility and effectiveness of laparoscopic intervention combined with temporary uterine artery clipping in the management of scar pregnancies, offering a valuable approach for clinicians faced with similar cases. Through this report, we aim to contribute to the existing literature on the optimal management of CSP and highlight the efficacy of laparoscopic surgery in this context. Full article
(This article belongs to the Special Issue Gynecological Surgery: Current Perspectives and Future Challenges)
10 pages, 1065 KiB  
Communication
Single Amino Acid Substitution in the Matrix Protein of Rabies Virus Is Associated with Neurovirulence in Mice
by Michiko Harada, Aya Matsuu, Yoshihiro Kaku, Akiko Okutani, Yusuke Inoue, Guillermo Posadas-Herrera, Satoshi Inoue and Ken Maeda
Viruses 2024, 16(5), 699; https://doi.org/10.3390/v16050699 (registering DOI) - 28 Apr 2024
Abstract
Rabies is a fatal encephalitic infectious disease caused by the rabies virus (RABV). RABV is highly neurotropic and replicates in neuronal cell lines in vitro. The RABV fixed strain, HEP-Flury, was produced via passaging in primary chicken embryonic fibroblast cells. HEP-Flury showed [...] Read more.
Rabies is a fatal encephalitic infectious disease caused by the rabies virus (RABV). RABV is highly neurotropic and replicates in neuronal cell lines in vitro. The RABV fixed strain, HEP-Flury, was produced via passaging in primary chicken embryonic fibroblast cells. HEP-Flury showed rapid adaptation when propagated in mouse neuroblastoma (MNA) cells. In this study, we compared the growth of our previously constructed recombinant HEP (rHEP) strain—based on the sequence of the HEP (HEP-Flury) strain—with that of the original HEP strain. The original HEP strain exhibited higher titer than rHEP and a single substitution at position 80 in the matrix (M) protein M(D80N) after incubation in MNA cells, which was absent in rHEP. In vivo, intracerebral inoculation of the rHEP-M(D80N) strain with this substitution resulted in enhanced viral growth in the mouse brain and a significant loss of body weight in the adult mice. The number of viral antigen-positive cells in the brains of adult mice inoculated with the rHEP-M(D80N) strain was significantly higher than that with the rHEP strain at 5 days post-inoculation. Our findings demonstrate that a single amino acid substitution in the M protein M(D80N) is associated with neurovirulence in mice owing to adaptation to mouse neuronal cells. Full article
(This article belongs to the Special Issue The World of Rhabdoviruses)
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15 pages, 5334 KiB  
Article
Probable Role of Type IV Pili of Aeromonas hydrophila in Human Pathogenicity
by Agradip Bhattacharyya, Goutam Banerjee and Pritam Chattopadhyay
Pathogens 2024, 13(5), 365; https://doi.org/10.3390/pathogens13050365 (registering DOI) - 28 Apr 2024
Abstract
Background: Aeromonas hydrophila is a widely recognized broad-spectrum pathogen that primarily targets the gastrointestinal tract. Type IV pili (T4P) are proteinaceous nano-machines located on the bacterial cell surface, playing a crucial role in host colonization and infection. Regrettably, the T4P systems of A. [...] Read more.
Background: Aeromonas hydrophila is a widely recognized broad-spectrum pathogen that primarily targets the gastrointestinal tract. Type IV pili (T4P) are proteinaceous nano-machines located on the bacterial cell surface, playing a crucial role in host colonization and infection. Regrettably, the T4P systems of A. hydrophila remain largely underexplored. Methods: A. hydrophila genomes with complete genome assembly and annotation reports up to March 31, 2023, were obtained from the NCBI Genome database or KEGG genome database, followed by a global search for T4P secretion system genes. Protein sequences of these manually curetted genes were used as secondary quarry for Synteny analysis. Protein–protein interaction analysis was performed by string analysis and in silico study of genomic islands. Results: We identified 27 orthologs of type IV pili (T4P) nano-machine components in A. hydrophila. These orthologs are primarily distributed across three operons: pilABCD, pilMNOPQ, and pilVWXY. While the first two operons are commonly found in all experimental genomes, the presence of the pilVWXY operon, coding for 11 orthologs, is reported here for the first time in A. hydrophila. Notably, the complete pilVWXY operon is absent in nonvirulent strains. A genomic islands study between a nonvirulent and hypervirulent strain also confirms absence of most of the genes coded by pilVWXY in nonvirulent strain. Interestingly, among the 51 experimental genomes analyzed, the pilVWXY operon was completely absent in 10 strains, most of which are categorized as nonvirulent; Conclusions: The distribution of two major type IV pili (T4P) nano-machines, PilABCDMNOPQ and PilVWXY, is reported here for the first time in A. hydrophila. Additionally, this study suggests a potential role for the PilVWXY nano-machine in establishing human disease. Full article
(This article belongs to the Section Bacterial Pathogens)
20 pages, 717 KiB  
Article
Two-Month Consumption of Orange Juice Enriched with Vitamin D3 and Probiotics Decreases Body Weight, Insulin Resistance, Blood Lipids, and Arterial Blood Pressure in High-Cardiometabolic-Risk Patients on a Westernized Type Diet:Results from a Randomized Clinical Trial
by Emilia Papakonstantinou, Nikolaos Zacharodimos, Georgios Georgiopoulos, Christina Athanasaki, Dionysia-Lydia Bothou, Sofia Tsitsou, Foteini Lympaki, Stamatia Vitsou-Anastasiou, Olga S. Papadopoulou, Dimitrios Delialis, Evangelos C. Alexopoulos, Eleni Petsiou, Kalliopi Keramida, Agapi I. Doulgeraki, Ismini-Maria Patsopoulou, George-John E. Nychas and Chrysoula C. Tassou
Nutrients 2024, 16(9), 1331; https://doi.org/10.3390/nu16091331 (registering DOI) - 28 Apr 2024
Abstract
This study examined the effects of orange juice (OJ) supplemented with vitamin D3 (2000 IU) and probiotics (Lacticaseibacillus casei Shirota and Lacticaseibacillus rhamnosus GG, 108 cfu/mL) on cardiometabolic risk factors in overweight and obese adults following a Westernized-type diet. Fifty-three high-risk [...] Read more.
This study examined the effects of orange juice (OJ) supplemented with vitamin D3 (2000 IU) and probiotics (Lacticaseibacillus casei Shirota and Lacticaseibacillus rhamnosus GG, 108 cfu/mL) on cardiometabolic risk factors in overweight and obese adults following a Westernized-type diet. Fifty-three high-risk individuals were randomly assigned to one of two groups. Over 8 weeks, one group consumed a vitamin D3 and probiotic-enriched OJ and the other regular OJ (control). Diets remained unchanged and were documented through food diaries. Measures of metabolic and inflammatory markers and blood pressure were measured at the start and end of the study. Post-intervention, the enriched OJ group showed the following significant metabolic improvements (without changes in triglycerides, inflammation, or central blood pressure): reduced fasting insulin, peripheral blood pressure, body weight (−1.4 kg 95%CI: −2.4, −0.4), energy (−270 kcal 95%CI: −553.2, −13.7), macronutrient (dietary fat −238 kcal 95%CI: −11.9, −1.0; carbohydrates −155 kcal 95%CI: −282.4, −27.3; sugars −16.1 g 95%CI: −11.9, −1.0) intake, and better lipid profiles (total cholesterol −10.3 mg/dL 95%CI: −21.4, 0.9; LDL-C −7 mg/dL 95%CI: −13.5, −0.5). The enriched OJ led to weight loss, less energy/macronutrient consumption, improved lipid profiles, and increased insulin sensitivity after 8 weeks in those following a Westernized diet, thus indicating potential benefits for cardiometabolic risk. This study was a part of FunJuice-T2EDK-01922, which was funded by the EU Regional Development Fund and Greek National Resources. Full article
(This article belongs to the Special Issue Nutritional and Dietary Approaches to Diabetes)
16 pages, 92049 KiB  
Article
Pollination Syndrome, Florivory, and Breeding System of Satyrium nepalense var. ciliatum (Orchidaceae) in Central Yunnan, China
by Lei Tao, Kaifeng Tao, Qingqing Li, Yingduo Zhang, Xiangke Hu, Yan Luo and Lu Li
Plants 2024, 13(9), 1228; https://doi.org/10.3390/plants13091228 (registering DOI) - 28 Apr 2024
Abstract
Research on Satyrium nepalense var. ciliatum (Lindl.) Hook. f. has primarily focused on populations in Northwestern Yunnan, with limited studies on pollination syndromes and insect behavior. In addition, it is geographically limited in its breeding system studies. Therefore, this study selected S. nepalense [...] Read more.
Research on Satyrium nepalense var. ciliatum (Lindl.) Hook. f. has primarily focused on populations in Northwestern Yunnan, with limited studies on pollination syndromes and insect behavior. In addition, it is geographically limited in its breeding system studies. Therefore, this study selected S. nepalense var. ciliatum from Liangwang Mountain (Yunnan, China) to investigate its pollination syndromes, florivory, and breeding systems. Field observations, dissecting microscope, scanning electron microscopy (SEM), and paraffin section techniques were employed. Results revealed the pollination syndrome was characterized by an out-crossing trend, such as bright color, a developed rostellum, nectaries in the spur, and food hairs. The color and nectar attracted flower visitors, and florivory was observed. Some flower visitors pollinated their companion species. Ants were identified as floral visitors for the first time in Satyrium, although substantial pollination was not observed. Ants might be potential pollinators. S. nepalense var. ciliatum displayed a mixed breeding system, including selfing, out-crossing, and apomixis, with apomixis being predominant in nature. It is suggested that the pollination syndrome, florivory, and pollination competition would contribute to its mixed breeding systems, particularly leading to the occurrence of apomixis. Full article
(This article belongs to the Collection Feature Papers in Plant Ecology)
22 pages, 3045 KiB  
Article
Trajectory Planning for Cooperative Double Unmanned Surface Vehicles Connected with a Floating Rope for Floating Garbage Cleaning
by Mengdi Zhang, Xiang Zheng, Jianhua Wang, Zijun Pan, Wenbo Che and Haozhu Wang
J. Mar. Sci. Eng. 2024, 12(5), 739; https://doi.org/10.3390/jmse12050739 (registering DOI) - 28 Apr 2024
Abstract
Double unmanned surface vehicles (DUSVs) towing a floating rope are more effective at removing large floating garbage on the water’s surface than a single USV. This paper proposes a comprehensive trajectory planner for DUSVs connected with a floating rope for cooperative water-surface garbage [...] Read more.
Double unmanned surface vehicles (DUSVs) towing a floating rope are more effective at removing large floating garbage on the water’s surface than a single USV. This paper proposes a comprehensive trajectory planner for DUSVs connected with a floating rope for cooperative water-surface garbage collection with dynamic collision avoidance, which takes into account the kinematic constraints and dynamic cooperation constraints of the DUSVs, which reflects the current collection capacity of DUSVs. The optimal travel sequence is determined by solving the TSP problem with an ant colony algorithm. The DUSVs approach the garbage targets based on the guidance of target key points selected by taking into account the dynamic cooperation constraints. An artificial potential field (APF) combined with a leader–follower strategy is adopted so that the each USV passes from different sides of the garbage to ensure garbage capturing. For dynamic obstacle avoidance, an improved APF (IAPF) combined with a leader–follower strategy is proposed, for which a velocity repulsion field is introduced to reduce travel distance. A fuzzy logic algorithm is adopted for adaptive adjustment of the desired velocities of the DUSVs to achieve better cooperation between the DUSVs. The simulation results verify the effectiveness of the algorithm of the proposed planner in that the generated trajectories for the DUSVs successfully realize cooperative garbage collection and dynamic obstacle avoidance while complying with the kinematic constraints and dynamic cooperation constraints of the DUSVs. Full article
(This article belongs to the Special Issue Motion Control and Path Planning of Marine Vehicles—2nd Edition)
16 pages, 4260 KiB  
Article
Regulation of Root Exudation in Wheat Plants in Response to Alkali Stress
by Huan Wang, Shuting Zhao, Zexin Qi, Changgang Yang, Dan Ding, Binbin Xiao, Shihong Wang and Chunwu Yang
Plants 2024, 13(9), 1227; https://doi.org/10.3390/plants13091227 (registering DOI) - 28 Apr 2024
Abstract
Soil alkalization is an important environmental factor limiting crop production. Despite the importance of root secretion in the response of plants to alkali stress, the regulatory mechanism is unclear. In this study, we applied a widely targeted metabolomics approach using a local MS/MS [...] Read more.
Soil alkalization is an important environmental factor limiting crop production. Despite the importance of root secretion in the response of plants to alkali stress, the regulatory mechanism is unclear. In this study, we applied a widely targeted metabolomics approach using a local MS/MS data library constructed with authentic standards to identify and quantify root exudates of wheat under salt and alkali stresses. The regulatory mechanism of root secretion in alkali-stressed wheat plants was analyzed by determining transcriptional and metabolic responses. Our primary focus was alkali stress-induced secreted metabolites (AISMs) that showed a higher secretion rate in alkali-stressed plants than in control and salt-stressed plants. This secretion was mainly induced by high-pH stress. We discovered 55 AISMs containing –COOH groups, including 23 fatty acids, 4 amino acids, 1 amino acid derivative, 7 dipeptides, 5 organic acids, 9 phenolic acids, and 6 others. In the roots, we also discovered 29 metabolites with higher levels under alkali stress than under control and salt stress conditions, including 2 fatty acids, 3 amino acid derivatives, 1 dipeptide, 2 organic acids, and 11 phenolic acids. These alkali stress-induced accumulated carboxylic acids may support continuous root secretion during the response of wheat plants to alkali stress. In the roots, RNAseq analysis indicated that 5 6-phosphofructokinase (glycolysis rate-limiting enzyme) genes, 16 key fatty acid synthesis genes, and 122 phenolic acid synthesis genes have higher expression levels under alkali stress than under control and salt stress conditions. We propose that the secretion of multiple types of metabolites with a –COOH group is an important pH regulation strategy for alkali-stressed wheat plants. Enhanced glycolysis, fatty acid synthesis, and phenolic acid synthesis will provide more energy and substrates for root secretion during the response of wheat to alkali stress. Full article
18 pages, 3870 KiB  
Article
Impact of Hillslope Agriculture on Soil Compaction and Seasonal Water Dynamics in a Temperate Vineyard
by Jasmina Defterdarović, Lana Filipović, Gabrijel Ondrašek, Igor Bogunović, Ivan Dugan, Vinod Phogat, Hailong He, Mehran Rezaei Rashti, Ehsan Tavakkoli, Thomas Baumgartl, Abolfazl Baghbani, Timothy I. McLaren and Vilim Filipović
Land 2024, 13(5), 588; https://doi.org/10.3390/land13050588 (registering DOI) - 28 Apr 2024
Abstract
Major losses of agricultural production and soils are caused by erosion, which is especially pronounced on hillslopes due to specific hydrological processes and heterogeneity. Therefore, the aim of this study was to assess the impact of agricultural management on the compaction, infiltration, and [...] Read more.
Major losses of agricultural production and soils are caused by erosion, which is especially pronounced on hillslopes due to specific hydrological processes and heterogeneity. Therefore, the aim of this study was to assess the impact of agricultural management on the compaction, infiltration, and seasonal water content dynamics of the hillslope. Measurements were made at the hilltop and footslope, i.e., soil water content and potential were measured using sensors, wick lysimeters were used to quantify water flux, while a mini-disk infiltrometer was used to measure the infiltration rate and calculate the unsaturated hydraulic conductivity (K_unsat). Soil texture showed differences between hillslope positions, i.e., at the hilltop after 50 cm depth, the soil is classified as silty clay loam, and from 75 cm onward, the soil is silty clay, while at the footslope, the soil is silt loam even at the deeper depths. The results show a higher K_unsat at the footslope as well as higher average water volumes collected in wick lysimeters compared to the hilltop. Average water volumes showed a statistically significant difference at p < 0.01 between the hilltop and the footslope. The soil water content and water potential sensors showed higher values at the footslope at all depths, i.e., 8.0% at 15 cm, 8.4% at 30 cm, and 27.3% at 45 cm. The results show that, even though the vineyard is located in a relatively small area, soil heterogeneity is present, affecting the water flow along the hillslope. This suggests the importance of observing water movement in the soil, especially today when facing extreme weather (e.g., short-term high-intensity rainfall events) in order to protect soil and water resources. Full article
(This article belongs to the Special Issue Ecosystem Disturbances and Soil Properties)
16 pages, 2161 KiB  
Article
The Remaining Life Prediction of Rails Based on Convolutional Bi-Directional Long and Short-Term Memory Neural Network with Residual Self-Attention Mechanism
by Gang Huang, Lin Gong, Yuhan Zhang, Zhongmei Wang and Songlin Yuan
Appl. Sci. 2024, 14(9), 3781; https://doi.org/10.3390/app14093781 (registering DOI) - 28 Apr 2024
Abstract
In the railway industry, the rail is the basic load-bearing structure of railway tracks. The prediction of the remaining useful life (RUL) for rails is important to avoid unexpected system failures and reduce the cost of maintaining the system. However, the existing detection [...] Read more.
In the railway industry, the rail is the basic load-bearing structure of railway tracks. The prediction of the remaining useful life (RUL) for rails is important to avoid unexpected system failures and reduce the cost of maintaining the system. However, the existing detection of rail flaws is difficult, the rail deterioration mechanisms are diverse, and the traditional data-driven methods have insufficient feature extraction. This causes low prediction accuracy. With objectives set in relation to the problems outlined above, a rail RUL prediction approach based on a convolutional bidirectional long- and short-term memory neural network with a residual self-attention (CNNBiLSTM-RSA) mechanism is designed. Firstly, the pre-processed vibration data are taken as the input for the convolutional bi-directional long- and short-term memory neural network (CNNBiLSTM) to extract the forward and backward dependencies and features of the rail data. Secondly, the RSA mechanism is introduced in order to obtain the contributions of the features at different moments during the degradation process of the rail. Finally, an end-to-end RUL prediction implementation based on the convolutional bi-directional long- and short-term memory neural network with the residual self-attention mechanism is established. The experiments were carried out using the full life-cycle data of rails collected at the railway site. The results show that the method achieves a higher accuracy in the RUL prediction of rails. Full article
(This article belongs to the Section Computing and Artificial Intelligence)
15 pages, 1746 KiB  
Article
Widely Targeted Metabolomic Analysis Revealed the Diversity in Milk from Goats, Sheep, Cows, and Buffaloes and its Association with Flavor Profiles
by Fuhong Zhang, Yaling Wang, Baolong Liu, Ping Gong, Chenbo Shi, Lu Zhu, Jianqing Zhao, Weiwei Yao, Qingqing Liu and Jun Luo
Foods 2024, 13(9), 1365; https://doi.org/10.3390/foods13091365 (registering DOI) - 28 Apr 2024
Abstract
The milk flavor can be attributed to the presence of numerous flavor molecules and precursors. In this study, we employed widely targeted metabolomic analysis techniques to analyze the metabolic profiles of various milk samples obtained from goats, sheep, dairy cows, and buffaloes. A [...] Read more.
The milk flavor can be attributed to the presence of numerous flavor molecules and precursors. In this study, we employed widely targeted metabolomic analysis techniques to analyze the metabolic profiles of various milk samples obtained from goats, sheep, dairy cows, and buffaloes. A total of 631 metabolites were identified in the milk samples, which were further categorized into 16 distinct classes. Principal component analysis (PCA) suggested that the metabolite profiles of samples from the same species exhibit clustering, while separated patterns of metabolite profiles are observed across goat, sheep, cow, and buffalo species. The differential metabolites between the groups of each species were screened based on fold change and variable importance in projection (VIP) values. Five core differential metabolites were subsequently identified, including 3-(3-hydroxyphenyl)-3-hydroxypropanoic acid, inosine 5′-triphosphate, methylcysteine, N-cinnamylglycine, and small peptide (L-tyrosine–L-aspartate). Through multiple comparisons, we also screened biomarkers of each type of milk. Our metabolomic data showed significant inter-species differences in the composition and concentration of some compounds, such as organic acids, amino acids, sugars, nucleotides, and their derivatives, which may affect the overall flavor properties of the milk sample. These findings provided insights into the molecular basis underlying inter-species variations in milk flavor. Full article
(This article belongs to the Special Issue Metabolomics in Food)
11 pages, 1524 KiB  
Article
Synthesis and Characterization of 2D Ternary Compound TMD Materials Ta3VSe8
by Yuanji Ma, Yuhan Du, Wenbin Wu, Zeping Shi, Xianghao Meng and Xiang Yuan
Micromachines 2024, 15(5), 591; https://doi.org/10.3390/mi15050591 (registering DOI) - 28 Apr 2024
Abstract
Two-dimensional (2D) transition metal dichalcogenides (TMDs) are garnering considerable scientific interest, prompting discussion regarding their prospective applications in the fields of nanoelectronics and spintronics while also fueling groundbreaking discoveries in phenomena such as the fractional quantum anomalous Hall effect (FQAHE) and exciton dynamics. [...] Read more.
Two-dimensional (2D) transition metal dichalcogenides (TMDs) are garnering considerable scientific interest, prompting discussion regarding their prospective applications in the fields of nanoelectronics and spintronics while also fueling groundbreaking discoveries in phenomena such as the fractional quantum anomalous Hall effect (FQAHE) and exciton dynamics. The abundance of binary compound TMDs, such as MX2 (M = Mo, W; X = S, Se, Te), has unlocked myriad avenues of exploration. However, the exploration of ternary compound TMDs remains relatively limited, with notable examples being Ta2NiS5 and Ta2NiSe5. In this study, we report the synthesis of a new 2D ternary compound TMD materials, Ta3VSe8, employing the chemical vapor transport (CVT) method. The as-grown bulk crystal is shiny and can be easily exfoliated. The crystal quality and structure are verified by X-ray diffraction (XRD), while the surface morphology, stoichiometric ratio, and uniformity are determined by scanning electron microscopy (SEM). Although the phonon property is found stable at different temperatures, magneto-resistivity evolves. These findings provide a possible approach for the realization and exploration of ternary compound TMDs. Full article
(This article belongs to the Special Issue Devices Based on Two-Dimensional Materials: Materials and Fabrication)
17 pages, 5960 KiB  
Article
Crushing Response and Optimization of a Modified 3D Re-Entrant Honeycomb
by Jun Zhang, Bo-Qiang Shi, Bo Wang and Guo-Qing Yu
Materials 2024, 17(9), 2083; https://doi.org/10.3390/ma17092083 (registering DOI) - 28 Apr 2024
Abstract
A modified 3D re-entrant honeycomb is designed and fabricated utilizing Laser Cladding Deposition (LCD) technology, the mechanical properties of which are systematically investigated by experimental and finite element (FE) methods. Firstly, the influences of honeycomb angle on localized deformation and the response of [...] Read more.
A modified 3D re-entrant honeycomb is designed and fabricated utilizing Laser Cladding Deposition (LCD) technology, the mechanical properties of which are systematically investigated by experimental and finite element (FE) methods. Firstly, the influences of honeycomb angle on localized deformation and the response of force are studied by an experiment. Experimental results reveal that the honeycomb angles have a significant effect on deformation and force. Secondly, a series of numerical studies are conducted to analyze stress characteristics and energy absorption under different angles (α) and velocities (v). It is evident that two variables play an important role in stress and energy. Thirdly, response surface methodology (RSM) and the Non-Dominated Sorting Genetic Algorithm II (NSGA-II) are implemented with high precision to solve multi-objective optimization. Finally, the final compromise solution is determined based on the fitness function, with an angle of 49.23° and an impact velocity of 16.40 m/s. Through simulation verification, the errors of energy absorption (EA) and peak crush stress (PCS) are 9.26% and 0.4%, respectively. The findings of this study offer valuable design guidance for selecting the optimal design parameters under the same mass conditions to effectively enhance the performance of the honeycomb. Full article
17 pages, 1212 KiB  
Article
A Novel Inserting Pilot Radio over Fiber System without the Bit Walk-Off Effect for the Generation and Distribution of Frequency 16-Tupling Millimeter Waves by Mach–Zehnder Modulators
by Xu Chen, Xinqiao Chen, Siyuan Dai, Bin Li and Ling Wang
Photonics 2024, 11(5), 410; https://doi.org/10.3390/photonics11050410 (registering DOI) - 28 Apr 2024
Abstract
A novel inserting pilot scheme to generate and distribute a frequency 16-tupling millimeter wave (MMW) radio over fiber (ROF) system without the bit walk-off effect via Mach–Zehnder modulators (MZMs) is proposed. The operation principle is analyzed and the feasibility of our proposed scheme [...] Read more.
A novel inserting pilot scheme to generate and distribute a frequency 16-tupling millimeter wave (MMW) radio over fiber (ROF) system without the bit walk-off effect via Mach–Zehnder modulators (MZMs) is proposed. The operation principle is analyzed and the feasibility of our proposed scheme is verified by simulation test. The main part of our scheme is a ±8th-order sidebands generator (SG), which is constructed by four MZMs connected in parallel. In the back-to-back (BTB) transmission case, by properly adjusting the voltage and initial phase of the radio frequency (RF) drive signals of the MZMs, ±8th-order sidebands are generated by the SG. In the data transmission case, the data signal is first split into two beams, one of which modulates the RF drive signal with an electrical phase modulator (PM) while the other is amplified by an electrical gainer (EG), and then the two beams are combined into one and used as the composite RF drive signal of the MZMs. By adjusting the modulation index of the PM and the gain of the EG, the data signal can only be modulated to the +8th-order sideband of the output of the SG. The optical carrier from the continuous wave (CW) laser is split into two paths: one is sent into the SG, and the other is used as a pilot signal. The output signal of SG is combined with the pilot signal and is transmitted to the base station (BS) via optical fiber. At the BS, the pilot signal is filtered out by a fiber Bragg grating (FBG) and used as the carrier for the uplink for carrier reuse. After filtering out the pilot, the signal from the FBG, which is composed of ±8th-order sidebands, is injected into a photodetector, and a frequency 16-tupling MMW with downlink data is generated. The key parameters’ influence on the bit error rate (BER) and Q factor in the system is also analyzed. Our scheme can not only effectively overcome the bit walk-off effect caused by optical fiber chromatic dispersion and greatly increase the fiber transmission distance but can also effectively improve the performance and the tunability of system. Therefore, it has important application prospects in ROF systems. Full article
(This article belongs to the Section Optical Communication and Network)
20 pages, 1622 KiB  
Article
Carbonate Stable Isotope Data Suggest Freshwater Environment for the McMurray Formation (Aptian), Alberta, Canada
by Franek Hasiuk, Abdullah Wahbi, Luis González, Mike Blum and Greg Ludvigson
Geosciences 2024, 14(5), 120; https://doi.org/10.3390/geosciences14050120 (registering DOI) - 28 Apr 2024
Abstract
Stable isotope, trace element, and cathodoluminescence analyses were performed on gastropods and matrix from rock cores of the Middle to Upper McMurray Formation (Lower Cretaceous/Aptian, Northwestern Alberta, Canada) to characterize the extent to which pristine material remained from which depositional environmental conditions could [...] Read more.
Stable isotope, trace element, and cathodoluminescence analyses were performed on gastropods and matrix from rock cores of the Middle to Upper McMurray Formation (Lower Cretaceous/Aptian, Northwestern Alberta, Canada) to characterize the extent to which pristine material remained from which depositional environmental conditions could be estimated. Aragonitic gastropod shells retain their original depositional chemistry, and along with other closely associated authigenic carbonate components, indicate that the Middle to Upper McMurray Formation was deposited in a freshwater environment that was part of a continent-scale river system. Full article
19 pages, 16794 KiB  
Article
A Benchmark for UAV-View Natural Language-Guided Tracking
by Hengyou Li, Xinyan Liu and Guorong Li
Electronics 2024, 13(9), 1706; https://doi.org/10.3390/electronics13091706 (registering DOI) - 28 Apr 2024
Abstract
We propose a new benchmark, UAVNLT (Unmanned Aerial Vehicle Natural Language Tracking), for the UAV-view natural language-guided tracking task. UAVNLT consists of videos taken from UAV cameras from four cities for vehicles on city roads. For each video, vehicles’ bounding boxes, trajectories, and [...] Read more.
We propose a new benchmark, UAVNLT (Unmanned Aerial Vehicle Natural Language Tracking), for the UAV-view natural language-guided tracking task. UAVNLT consists of videos taken from UAV cameras from four cities for vehicles on city roads. For each video, vehicles’ bounding boxes, trajectories, and natural language are carefully annotated. Compared to the existing data sets, which are only annotated with bounding boxes, the natural language sentences in our data set can be more suitable for many application fields where humans take part in the system for that language, being not only more friendly for human–computer interaction but also capable of overcoming the appearance features’ low uniqueness for tracking. We tested several existing methods on our new benchmarks and found that the performance of the existing methods was not satisfactory. To pave the way for future work, we propose a baseline method suitable for this task, achieving state-of-the-art performance. We believe our new data set and proposed baseline method will be helpful in many fields, such as smart city, smart transportation, vehicle management, etc. Full article
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