bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardioselective versus Non-Cardioselective Beta-Blockers and Outcomes in Patients with Atrial Fibrillation and Chronic Obstructive Pulmonary Disease
Authors: Vlachopoulou Dimitra , Balomenakis Charalampos , Kartas Anastasios , Samaras Athanasios , Papazoglou Andreas S. , Moysidis Dimitrios V. , Barmpagiannos Konstantinos , Kyriakou Melina , Papanastasiou Anastasios , Baroutidou Amalia , Vouloagkas Ioannis , Tzikas Apostolos , Giannakoulas George
Published: April 2023

Background: Atrial fibrillation (AF) and chronic obstructive pulmonary disease (COPD) have been independently associated with increased mortality; however, there is no evidence regarding beta-blocker cardioselectivity and long-term outcomes in patients with AF and concurrent COPD. Methods: This post hoc analysis of the MISOAC-AF randomized trial (NCT02941978) included patients hospitalized with comorbid AF. At discharge, all patients were classified according to the presence of COPD; patients with COPD on beta-blockers were classified according to beta-blocker cardioselectivity. Adjusted hazard ratios (aHRs) were calculated by using multivariable Cox regression models. The primary outcome was all-cause mortality, and the secondary outcomes were cardiovascular mortality and hospitalizations. Results: Of 1103 patients with AF, 145 (13%) had comorbid COPD. Comorbid COPD was associated with an increased risk of all-cause (aHR, 1.33; 95% confidence interval (CI), 1.02 to 1.73) and cardiovascular mortality (aHR 1.47; 95% CI, 1.10 to 1.99), but not with increased risk of hospitalizations (aHR 1.10; 95% CI, 0.82 to 1.48). The use of cardioselective versus non-cardioselective beta-blockers was associated with similar all-cause mortality (aHR 1.10; 95% CI, 0.63 to 1.94), cardiovascular mortality (aHR 1.33; 95% CI, 0.71 to 2.51), and hospitalizations (aHR 1.65; 95% CI 0.80 to 3.38). Conclusions: In recently hospitalized patients with AF, the presence of COPD was independently associated with increased risk of all-cause and cardiovascular mortality. No difference between cardioselective and non-cardioselective beta-blockers, regarding clinical outcomes, was identified.
Ocular Surface Changes in Treatment-Naive Thyroid Eye Disease
Authors: Liao Xulin , Lai Kenneth Ka Hei , Aljufairi Fatema Mohamed Ali Abdulla , Chen Wanxue , Hu Zhichao , Wong Hanson Yiu Man , Jia Ruofan , Wei Yingying , Tham Clement Chee Yung , Pang Chi Pui , Chong Kelvin Kam Lung
Published: April 2023

Objective: To investigate the association of meibomian gland dysfunction (MGD) and ocular surface exposure with tear film instability in untreated thyroid eye disease (TED) patients. Methods: A cross-sectional study of TED patients from September 2020 to September 2022 was conducted. Ocular surface parameters included ocular surface disease index (OSDI), tear meniscus height (TMH), non-invasive tear break-up time (NITBUT), partial blinking rate, lipid layer thickness (LLT), meibomian gland dropout (meiboscore), Schirmer’s test, and corneal punctate epithelial erosions (PEE). Ocular surface exposure was assessed by the margin reflex distances of the upper and lower eyelid (MRD1 and MRD2), the amount of exophthalmos, lateral flare, and lagophthalmos. Results: In total, 152 eyes from 76 TED patients (64 females and 12 males, age 42.99 ± 12.28 years) and 93 eyes from 61 healthy controls (51 females and 10 males, age 43.52 ± 17.93 years) were examined. Compared with control eyes, TED eyes had higher OSDI, TMH, LLT, and PEE; shorter NITBUT; and worse meiboscore (all p < 0.05). They also had larger amounts of exophthalmos, longer MRD1, more lateral flare, and lagophthalmos. Multivariate analysis identified an association of the tear film instability with lagophthalmos (β = −1.13, 95%CI: −2.08, −0.18) and severe MGD in the lower eyelid (β = −5.01, 95%CI = −7.59, −2.43). Conclusions: Dry eye in TED is mainly manifested as evaporative dry eye disease. Severe lower eyelid MGD and worse lagophthalmos were significantly associated with tear film instability in treatment-naive TED patients.
Potentially Inappropriate Medication Use among Underserved Older Latino Adults
Authors: King Ebony , Bazargan Mohsen , Entsuah Nana , Tokumitsu Sayaka W. , Wisseh Cheryl , Adinkrah Edward K.
Published: April 2023

Background: Previous studies identified alarming increases in medication use, polypharmacy, and the use of potentially inappropriate medications (PIMs) among minority older adults with multimorbidity. However, PIM use among underserved older Latino adults is still largely unknown. The main objective of this study is to examine the prevalence of PIM use among underserved, community-dwelling older Latino adults. This study examines both the complexity of polypharmacy in this community and identifies associations between PIM and multimorbidity, polypharmacy, and access to medical care among this segment of our population. Methods: This community-based, cross-sectional study included 126 community-dwelling Latinos aged 65 years and older. The updated 2019 AGS Beers Criteria was used to identify participants using PIMs. We used multinomial logistic regression to examine the independent association of PIM with several independent variables including demographic characteristics, the number of chronic conditions, the number of prescription medications used, level of pain, and sleep difficulty. In addition, we present five cases in order to offer greater insight into PIM use among our sample. Results: One-third of participants had at least one use of PIM. Polypharmacy (≥5 medications) was observed in 55% of our sample. In addition, 46% took drugs to be used with caution (UWC). In total, 16% were taking between 9 and 24 medications, whereas 39% and 46% were taking 5 to 8 and 1 to 4 prescription medications, respectively. The multinomial logit regression analysis showed that (controlling for demographic variables) increased PIM use was associated with an increased number of prescription medications, number of chronic conditions, sleep difficulty, lack of access to primary care, financial strains, and poor self-rated health. Discussion: Both qualitative and quantitative analysis revealed recurrent themes in the missed identification of potential drug-related harm among underserved Latino older adults. Our data suggest that financial strain, lack of access to primary care, as well as an increased number of medications and co-morbidity are inter-connected. Lack of continuity of care often leads to fragmented care, putting vulnerable patients at risk of polypharmacy and drug–drug interactions as clinicians lack access to a current and complete list of medications patients are using at any given time. Therefore, improving access to health care and thereby continuity of care among older Latino adults with multimorbidity has the potential to reduce both polypharmacy and PIM use. Programs that increase access to regular care and continuity of care should be prioritized among multimorbid, undeserved, Latino older adults in an effort toward improved health equity.
Mastopexy Strategies for Ptotic Breasts in Patients Choosing Autologous Reconstruction Following Prophylactic Mastectomy
Authors: Varnava Charalampos , Bogusch Miriam , Wellenbrock Sascha , Hirsch Tobias , Wiebringhaus Philipp , Kueckelhaus Maximilian
Published: April 2023

Background: Autologous breast reconstruction is a reliable solution for many patients after mastectomy. While this technique represents a standardized approach in many patients, patients with ptotic breasts may require a combination of procedures to achieve an aesthetically pleasing result. Methods: We reviewed the mastectomy and free-flap breast reconstruction procedures performed at our institution from 2018 to 2022 in patients with ptotic breasts. The technique used to address the ptosis was put in focus as we present the four strategies used by our reconstructive surgeons. We performed two different one-stage and two different two-stage procedures. The difference between the two-stage procedures was the way the nipple areola complex was treated (inferior dermal pedicle or free skin graft). The difference between the one-stage procedures was the time of execution of the mastopexy/breast reduction (before or after the mastectomy and autologous breast reconstruction). Results: The one-stage procedure was performed with a free NAC in three patients and with a pedicled NAC in five patients. The two-stage procedure was performed in seven patients, with six of them undergoing mastopexy before and one patient undergoing mastopexy after the bilateral mastectomy and autologous reconstruction. No flap loss or total loss of the nipple areola complex occurred. Partial NAC loss was observed in five breasts in the single-stage group without any occurrence in the double-stage group. Conclusions: While both one- and two-stage procedures were performed in a safe fashion with satisfactory results at our institution, larger trials are required to determine which procedure may yield the best possible outcomes. These outcomes should also include oncological safety and patient-reported outcomes.
Effects of Angiotensin Receptor-Neprilysin Inhibitors (ARNIs) on the Glucose and Fat Metabolism Biomarkers Leptin and Fructosamine
Authors: Ohnewein Bernhard , Shomanova Zornitsa , Paar Vera , Topf Albert , Jirak Peter , Fiedler Lukas , Granitz Christina , Van Almsick Vincent , Semo Dilvin , Zagidullin Naufal , Dieplinger Anna-Maria , Sindermann Juergen , Reinecke Holger , Hoppe Uta C. , Pistulli Rudin , Motloch Lukas J.
Published: April 2023

(1) Background: Heart failure with reduced ejection fraction (HFrEF) remains a major health burden. Angiotensin-Receptor-Neprilysin-Inhibitors (ARNIs) are an established HFrEF therapy which increases natriuretic peptide levels by inhibiting neprilysin. Leptin is a lipid metabolism parameter, which is also involved in glucose metabolism and is suggested to correlate with HF burden. While the hormone also seems to interact with neprilysin, potential associations with ARNI therapy have not been investigated yet. (2) Methods: To study this issue, we measured levels of leptin and fructosamine in consecutive 72 HFrEF patients before initiation of ARNI therapy and 3–6 months after initiation of therapy in two European centers. Biomarker levels were correlated with clinical parameters including ejection fraction, LVEF, and NYHA class. (3) Results: During a follow-up of up to 6 months, clinical parameters improved significantly (LVEF: 30.2 ± 7.8% to 37.6 ± 10.0%, (p < 0.001) and a significant improvement of the mean NYHA class with initial 32 patients in NYHA III or IV and 8 patients in NYHA class III/IV during the follow up (p < 0.001). The initial NT-proBNP levels of 2251.5 ± 2566.8 pg/mL significantly improved to 1416.7 ± 2145 pg/mL, p = 0.008) during follow up. ARNI therapy was also associated with an increase in leptin levels (17.5 ± 23.4 µg/L to 22.9 ± 29.3, p < 0.001) and furthermore, affected glucose metabolism indicated by elevation of fructosamine values (333.9 ± 156.8 µmol/L to 454.8 ± 197.8 µmol/L, p = 0.013). (4) Conclusion: while in the early phase of therapy, ARNI promotes clinical improvement of HFrEF, and it also seems to affect fat and glucose parameters, indicating significant metabolic implications of this therapy regime.
Measurement of the Fetal Ear Length Has No Clinical Value
Authors: Witkowski Sławomir , Respondek-Liberska Maria , Zieliński Rafał , Strzelecka Iwona
Published: April 2023

The long-term monitoring of a fetus with genetic and non-genetic anomalies is still a challenge for prenatal medicine. Ultrasound screening must be based on some measurement ranges, which show the trend of development of fetal body parts in a given period of time. One of them is the fetal ear auricle. This study presents an analysis of the fetal ear auricle length in healthy fetuses to establish normal ranges of fetal ear auricle length. The study group included 132 healthy fetuses. The gestational age of healthy fetuses ranged from 17.0 to 39.5 weeks of gestation according to LMP. The range of fetal ear length measurement was 10.00–40.00 mm with an average value of 23.49 mm. In the group of fetuses in the second trimester of pregnancy, the range of fetal ear length measurement was 18.00–28.00 mm, whereas in the group of fetuses in the third trimester of pregnancy, the range was 16.00–40.00 mm. In order to check the usefulness of this parameter, an analysis of this marker in fetuses with extracardiac anomalies, including genetic and non-genetic disorders is shown. The fetal ear measurement can fall within the normal range even if there are some genetic or non-genetic disorders. Therefore, the fetal ear measurement does not provide any diagnostic value in terms of detecting any fetal genetic and non-genetic disorders, which is supported by the analysis of the data provided in this study. Our study has proved that measurement of the fetal ear auricle is possible; however, its clinical usefulness for perinatal management is currently very limited.
Informal Caregiver Stroke Program in Geriatric Rehabilitation of Stroke Patients: A Qualitative Study
Authors: Vielvoye Mariska , Nanninga Christa S. , Achterberg Wilco P. , Caljouw Monique A. A.
Published: April 2023

This study aimed to understand and gain insight into an informal caregiver program for caregivers of older stroke patients, which incorporates both skills training and education, in relation to caregiver burden. Semi-structured, in-depth interviews with individual informal caregivers were conducted at admission, at discharge, and six weeks after discharge. The program consisted of informal caregiver meetings, walk-in days, psychoeducation, and weekend leave after admission to a rehabilitation stroke unit in a nursing home. Eleven informal caregivers participated in the study. The informal caregiver meetings and walk-in days provided more insight into the (level of) functioning of the stroke patients, more skills in guiding them, and better communication with the multidisciplinary care team. During weekend leave, caregivers experienced what their roles as caregivers entailed. Six weeks after discharge, caregivers said that they did not miss any guidance during admission and that they were positive about the future. About half of the caregivers found the caregiver situation disappointing, and combining care tasks with daily tasks appeared to be difficult. Offering informal caregivers a tailor-made program during rehabilitation and good communication helps to diminish caregiver burden in the post-discharge phase when their relatives are back home.
Tinnitus Guidelines and Their Evidence Base
Authors: Langguth Berthold , Kleinjung Tobias , Schlee Winfried , Vanneste Sven , De Ridder Dirk
Published: April 2023

Evidence-based medicine (EBM) is generally accepted as the gold standard for high-quality medicine and, thus, for managing patients with tinnitus. EBM integrates the best available scientific information with clinical experience and patient values to guide decision-making about clinical management. To help health care providers and clinicians, the available evidence is commonly translated into medical or clinical guidelines based on a consensus. These involve a systematic review of the literature and meta-analytic aggregation of research findings followed by the formulation of clinical recommendations. However, this approach also has limitations, which include a lack of consideration of individual patient characteristics, the susceptibility of guideline recommendations to material and immaterial conflicts of interest of guideline authors and long latencies till new knowledge is implemented in guidelines. A further important aspect in interpreting the existing literature is that the absence of evidence is not evidence of absence. These circumstances could result in the decoupling of recommendations and their supporting evidence, which becomes evident when guidelines from different countries differ in their recommendations. This opinion paper will discuss how these weaknesses can be addressed in tinnitus.
Intrahepatic Cholangiocarcinoma and Acute Intermittent Porphyria: A Case Report
Authors: Guida Claudio Carmine , Nardella Maria , Fiorentino Leonardo , Latiano Tiziana , Napolitano Francesco , Ferrara Gaetano , Crisetti Annalisa , Mazzoccoli Gianluigi , Aucella Francesco , Aucella Filippo
Published: April 2023

Patients suffering from different forms of acute hepatic porphyria present a high risk of primary liver cancer, specifically hepatocellular carcinoma and cholangiocarcinoma, determined by the activity of the disease even though an exact mechanism of carcinogenesis has not been recognized yet. Here, we present the clinical case of a 72-year-old woman who, approximately 29 years after the diagnosis of acute intermittent porphyria, presented with intrahepatic cholangiocarcinoma with a histological diagnosis of adenocarcinoma starting from the biliary-pancreatic ducts, which was diagnosed during the clinical and anatomopathological evaluation of a pathological fracture of the femur.
Accelerated In Situ Inspection of Release Coating and Tool Surface Condition in Composites Manufacturing Using Global Mapping, Sparse Sensing, and Machine Learning
Authors: Schoenholz Caleb , Li Shuangshan , Bainbridge Kyle , Huynh Vy , Gray Alex , Zobeiry Navid
Published: April 2023

The interfacial adhesion, friction, and resulting tool-part interaction during composites manufacturing contribute to the formation of residual stresses and process-induced deformations (PIDs). Tool-part interaction and PIDs are highly sensitive to processing variabilities, one of which is the aging of the release coating and the surface condition of production tools. Unfortunately, due to a lack of available tool inspection methods, manufacturers often attempt to mitigate the aging of release coating based on know-how, leading to cost-deficient tool preparation schedules, lower end-part quality, and in some cases, higher levels of PIDs. This paper presents an in-situ inspection method to evaluate the physicochemical properties of release coating and the surface condition of large production tools by utilizing global mapping, sparse sensing, and machine learning (ML). ML methods are used in conjunction with multiple automated measurement techniques to quickly identify the condition of release coating or contamination on production tool surfaces in manufacturing environments. Results in this paper demonstrate that during autoclave processing, aerospace-grade release coatings undergo significant chemical changes, but may remain highly abhesive for more than twenty autoclave processing cycles. Using the proposed novel inspection technology, dry ice blasting (DIB) is also demonstrated to be an effective method for non-abrasively removing cured resin contamination and release coating from a tool surface. Overall, this paper demonstrates how the proposed inspection method can be integrated into a manufacturing process for automatic surface inspection of large tools to improve production efficiency and potentially mitigate PIDs in composites manufacturing.
Water Structure in the Utrish Nature Reserve (Black Sea) during 2020–2021 According to Thermistor Chain Data
Authors: Silvestrova Ksenia , Myslenkov Stanislav , Puzina Oksana , Mizyuk Artem , Bykhalova Olga
Published: April 2023

This paper reports the water temperature structure and associated coastal processes in the NE part of the Black Sea. In situ temperature was measured in the water area of the Utrish Nature Reserve. The thermistor chain was moored in 2020 and included 6–10 temperature sensors with an accuracy of ±0.025 °C and time step of one minute. The seasonal variations in the water temperature, upwelling events, internal waves and diurnal cycle were analyzed. The maximum value of SST (28.6 °C) was registered in the subsurface layer in August 2021; the minimum (7.7 °C) was registered in March 2022. Estimates of the diurnal temperature cycle were obtained according to spectral analysis. Summer months show the diurnal cycle more than 60% of the time, and the cold period shows it less than 10% of the time. Internal waves appeared in thermocline with periods from 5 min to 20 h. The strongest Ekman upwelling was registered in September 2021. The water temperature dropped from 26 °C to 16 °C in 10 h. Additionally, quality assessments of two hydrodynamic models were made. The models showed a good correlation (0.9) with water temperature measurements, but RMSE could reach 1–1.8 °C for subsurface layers. Temperature variability and its characteristics are an important basis for future coastal ecosystem studies in the Utrish.
Coastal Fish Fauna in the Cystoseira s.l. Algal Belts: Experiences from the Northern Adriatic Sea
Authors: Lipej Lovrenc , Ivajnšič Danijel , Pitacco Valentina , Trkov Domen , Mavrič Borut , Orlando-Bonaca Martina
Published: April 2023

Cystoseira s.l. forests are recognised as important habitats which host diverse coastal fish assemblages. Many fish species use such habitats as feeding, breeding, and nursery grounds. Since the coastal fish community depends on the availability of dense macroalgal belts, the decline of these habitats in the Mediterranean Sea also affects the density of coastal fish species. We studied the coastal fish assemblage in Cystoseira s.l. forests in three consecutive years 2019–2021 in the Gulf of Trieste (Adriatic Sea). Data on coastal fish fauna were collected by visual counts conducted by SCUBA diving. Data on algal cover and habitat types were obtained by recording with a video camera. Similarities and differences in the fish community were analysed in terms of habitat and substrate preferences. A total of 34 species were recorded in Cystoseira forests. The results of the present study show that the different algal cover and associated depth gradient have different effects on the fish assemblage in coastal waters, affecting species composition and abundance. For many species, particularly labrids and sea breams, there is a decreasing temporal trend in frequency of occurrence and density. However, fish community trends can be used as a good “proxy” to evaluate the algal belt status. Our results indicate that rapid conservation and restoration actions are needed to stem the decline of Cystoseira s.l. forests.
Joint Maritime Bunker Hedging and Operational Consumption Based on CVaR Optimization
Authors: Sun Xiaolin , Chen Jiajiao , Liu Wei
Published: April 2023

Maritime shipping is an important driver of global economic growth. Efficient green maritime technologies are critical for both the profitability and sustainability of shipping carriers due to the fact that fuel consumption has already made up 45–55% of the total operational cost of a ship. Moreover, the application of green maritime technologies also challenges the input/output of the maritime industry. Currently, there is a lack of coordination between the two strategies of maritime bunker management: one is the bunker procurement, which is faced with the fierce volatility of bunker fuel prices, and the other is the bunker consumption of vessel operation scheduling with applicable maritime technologies. To address the challenge posed by the new sulfur emission regulations, the two isolated strategies are inefficient. This study presents an integrated model that takes both the financial technology (bunker hedging) and the operational bunker cost efficiency (sailing speed and routing optimization under emission regulations) into account. The objective is to maximize the total rate of portfolio return considering the revenue and the cost simultaneously. By analyzing the Conditional Value at Risk (CVaR) risk measure, we examined the effects of the bunker spot, contract, and hedging in futures markets on the optimal joint solution. Numerical results from a real-world case study show that the optimized integrating financial and operational strategies yield the lowest expected total costs as well as the highest revenue with CVaR constraints. The findings provide a prospect for maritime shipping as an effective decision tool for bunker management under environmental regulations. The management insights of our study will benefit the corporate participants, policy makers, and researchers in liner shipping revenue and risk management.
Numerical Analysis of Energy Loss in Stall Zone for Full Tubular Pump Based on Entropy Generation Theory
Authors: Shi Lijian , Jiang Yuhang , Shi Wei , Sun Yi , Qiao Fengquan , Tang Fangping , Xu Tian
Published: April 2023

As a low-head and non-drive pump, the head reduction and stall advance are the key factors that restrict the popularization and application of the full tubular pump (FTP). In this paper, the shear stress transport (SST) k-ω turbulence model is used for the numerical calculation of the FTP. Additionally, based on the entropy generation theory, the energy loss and main distribution zones of the FTP under all working conditions are analyzed, and the mechanism of inducing its stall advance is explored. By comparison, we found that there is little difference between the numerical simulation results and the model test. Turbulence entropy generation has a high proportion under small flow conditions, which is mainly reflected in the outlet flow separation zone of the suction surface of the impeller blade, the guide vane inlet zone where inlet deviation exists, and the trailing edge of the guide vane where the flow separation exists. Compared with the axial flow pump (AFP), when the flow rate decreases, the clearance reflow between the stator and rotor induces the deterioration of the flow at the impeller inlet, and the turbulent entropy generation in the impeller channel increases rapidly, making the FTP enter the stall zone ahead of time. The clearance backflow affects the flow pattern of the inlet pipe, making the turbulence entropy generation in the outlet area of the inlet pipe increase. The total entropy generation in the stator–rotor region is little affected by the pump flow conditions, and it is mainly affected by different stator–rotor backflow clearance dimensions. This study can provide a reference for exploring the energy loss of the FTP and revealing its stall characteristics.
Corrosion Damage Evolution Study of the Offshore Cable-Stayed Bridge Anchorage System Based on Accelerated Corrosion Test
Authors: Yao Guowen , He Xuanbo , Long Hong , Lu Jiangshan , Wang Qianling
Published: April 2023

The cable-stayed bridge anchorage system is prone to serious corrosion problems in the offshore environment, threatening its service safety. Based on the copper accelerated salt spray (CASS) test, the anchorage system was subjected to accelerated corrosion and then dissected along the axial direction to study the corrosion damage evolution of the internal structure. This revealed the evolution of corrosion damage in the anchorage system of offshore cable-stayed bridges. The results show that in the offshore environment, a large number of corrosion factors enter the interior of the cable anchorage system through the splicing seam at the junction of the anchor cup and the connecting barrel, and spread to both ends, thus causing corrosion damage to the anchor cup, connecting barrel, filling medium and cable steel wires. Inside the cable of the anchorage system, cross-sections with a higher corrosion level on the outer circle steel wires will also have a higher overall corrosion level. The outer circle steel wires are less able to meet the strength requirements, because they withstand most of the corrosion effects, and the corrosion pits on the surface of the steel wires will render them much weaker than the design tensile strength and fracture. After the CASS test, the ductility of cable steel wires decreases from the inner circle to the outer circle, and the higher the corrosion level of steel wires, the more obvious the brittle indications; the steel wires tend to undergo brittle failure. In the design and manufacture of the cable-stayed bridge anchorage system, special attention should be paid to the corrosion protection of the splicing seam, as well as the corrosion condition and residual strength of steel wires in the outer circle of the cable, to delay the degradation of the mechanical properties and brittle damage of the anchorage system.
Robust Finite-Time Control of a Multi-AUV Formation Based on Prescribed Performance
Authors: Li Juan , Tian Zhenyang , Zhang Honghan , Li Wenbo
Published: April 2023

This paper focuses on the finite-time formation-control problem of a multi-AUV formation under unknown perturbations with prescribed performance. First, the nonlinear AUV model is transformed into a second-order integral model using feedback linearization. Suitable prescribed performance functions are selected to constrain the control errors of AUVs within a preset range and convert AUV tracking errors into unconstrained tracking errors using an error-conversion function to facilitate controller design. Finite-time sliding-mode disturbance observers are designed for unknown disturbances in the ocean so that they can accurately estimate the unknown disturbances in finite time. Based on the unconstrained tracking error and the unknown disturbance observer, the fast terminal sliding-mode formation controller is designed so that the multi-AUV formation can converge in finite time. Finally, the simulation experimental results show that the finite-time formation-control method with prescribed performance proposed in this paper can better cancel the unknown disturbance in the ocean in finite time and improve the robustness of the multi-AUV formation control.
Environmental Contours in the Adriatic Sea for Design and Analysis of Marine Structures
Authors: Mikulić Antonio , Parunov Joško
Published: April 2023

The environmental contours represent an approach for defining extreme environmental conditions, resulting in extreme responses of marine structures with a given return period. Over the past decade, an increasing number of studies have been developed dealing with the methods for defining environmental contours and enhancing their practical application in different marine environments. In the present study, environmental contours describing significant wave heights and peak wave periods are created for the Adriatic Sea. This small semi-enclosed sea basin within the Mediterranean Sea encounters increasing maritime and offshore activities. Considering also a great but still unused potential for the installation of renewable energy facilities, the main motives for the presented study are concluded. The environmental contours are established based on 24 years of hindcast wave data extracted from the WorldWaves database. Joint distributions consisting of the marginal distribution of significant wave height and conditional distributions of peak wave periods are used as a basis for the creation of environmental contours using the IFORM and ISORM methods. Return periods of 1 year, 25 years, and 100 years are considered relevant for the marine operation, design of ships, and offshore structures, respectively. A possibility of environmental contour practical application to the calculation of global wave loads upon ship structures is presented. Based on the uncertainty assessment performed, conservative environmental contours for the whole Adriatic are also presented.
Efficient Water Segmentation with Transformer and Knowledge Distillation for USVs
Authors: Zhang Jingting , Gao Jiantao , Liang Jinshuo , Wu Yiqiang , Li Bin , Zhai Yang , Li Xiaomao
Published: April 2023

Water segmentation is a critical task for ensuring the safety of unmanned surface vehicles (USVs). Most existing image-based water segmentation methods may be inaccurate due to light reflection on the water. The fusion-based method combines the paired 2D camera images and 3D LiDAR point clouds as inputs, resulting in a high computational load and considerable time consumption, with limits in terms of practical applications. Thus, in this study, we propose a multimodal fusion water segmentation method that uses a transformer and knowledge distillation to leverage 3D LiDAR point clouds in order to assist in the generation of 2D images. A local and non-local cross-modality fusion module based on a transformer is first used to fuse 2D images and 3D point cloud information during the training phase. A multi-to-single-modality knowledge distillation module is then applied to distill the fused information into a pure 2D network for water segmentation. Extensive experiments were conducted with a dataset containing various scenes collected by USVs in the water. The results demonstrate that the proposed method achieves approximately 1.5% improvement both in accuracy and MaxF over classical image-based methods, and it is much faster than the fusion-based method, achieving speeds ranging from 15 fps to 110 fps.
Fusion2Fusion: An Infrared–Visible Image Fusion Algorithm for Surface Water Environments
Authors: Lu Cheng , Qin Hongde , Deng Zhongchao , Zhu Zhongben
Published: April 2023

Infrared images can rely on the thermal radiation of objects for imaging, independent of lighting conditions. Furthermore, because the thermal radiation produced by targets such as people, vehicles, and boats differs greatly from the background, it is able to distinguish objects from their environment as well. These characteristics of infrared can be complemented with visible images, which are rich in color information but vulnerable to lighting conditions. Therefore, the fusion of IR and visible images can provide a better perception of the environment. In this paper, we propose a new infrared–visible fusion algorithm. It consists of three parts: feature extraction, fusion, and reconstruction. The attention mechanism is introduced into the feature extraction to better extract features and we propose a new way of describing the fusion task. The relationship between the two inputs is balanced by introducing a fused image obtained by summing the infrared and visible images. It is also optimized for sky layering and water surface ripples, which are common in water environments. The edge information is enhanced in the loss function and noise reduction is performed. Through comparison experiments, our algorithm achieves better results.
Long-Term Variations of Biogenic Elements and Nutritional Status in Daya Bay, Northern South China Sea
Authors: Guo Zhicheng , Xiao Yayuan , Liu Yong , Wu Peng , Li Chunhou
Published: April 2023

This study explored the variations in the characteristics of the trophic structure of Daya Bay island waters over the last four decades based on the survey findings and research data on biogenic elements (dissolved inorganic nitrogen (DIN), NO2−, NO3−, NH4+, PO43−, and SiO32−) in Daya Bay during 1985–2021. At this time, the DIN concentration increased from 21.14 µg·L−1 to 558.42 µg·L−1 (26.41-fold increase), whereas the SiO32− concentration increased by only 3.6-fold. The PO43− concentrations attained a peak in 2004 and experienced a steady decline over the rest of the survey period. The fractions of NH4+, NO3−, and NO2− in DIN changed from 0.45, 0.40, and 0.15 in 1986 to 0.26, 0.74, and 0.003 in 2021, respectively. Overall, the mean values of NH4+, NO3−, and NO2− accounted for 45.2%, 42.5%, and 12.3%, respectively. The N/P(DIN/PO43−) ratio in Daya Bay increased from 28.08 in the 1980s to 51.63 in the 2010s. Meanwhile, the nutrient limitation conditions showed a gradual shift from N-limited to P-limited conditions. According to the nutrient quality index (NQI) analysis, the trophic state level of Daya Bay waters fell into the oligotrophic category 30 years ago (1985–2002, NQI < 2), whereas it increased from the mesotrophic level in 2005 (NQI = 2.03) to the eutrophic level in 2019 (NQI = 3.33) over the last 20 years. The results based on the eutrophication index (EI) of Daya Bay waters were generally consistent with those based on the NQI, displaying that the trophic level of Daya Bay waters indicated an increasing trend from 2005 to 2019. Moreover, the assessment data in 2021 indicated a decrease in the NQI to 0.90, thereby attaining the oligotrophic level again. This may be related to the decrease in aquacultural area in the bay over the last two years. The correlation analysis among the DIN, PO43−, and nutrient levels of Daya Bay waters indicated that the input of nitrogen and phosphorus was the primary reason for the higher nutrient levels in the water bodies; among them, municipal sewage discharge, aquaculture, and atmospheric deposition from industry are the main factors for the over importation. This indicates that the changes in the biogenic element concentrations led to variations in the trophic structure and level of Daya Bay and may be attributed to population growth and the development of the seaside industry and agriculture in the region.
Desalination Plant for Irrigation Purposes Driven by an Inland Floating Photovoltaic System
Authors: Del Rio-Gamero B. , Rodríguez-López Edgar , Schallenberg-Rodríguez Julieta
Published: April 2023

In places where water and land are scarce it is vital to look for innovative solutions that can ensure water production for agricultural purposes. This study considers the treatment of water using desalination processes to meet the quality requirements needed for irrigation purposes in agriculture. As the water is stored in a pond, an inland floating photovoltaic (FPV) system is proposed to meet the desalination energy demand. This system would enable energy production without using additional land that could otherwise be used for agricultural purposes. The use of FPV technology also reduces water evaporation, thus avoiding unnecessary energy consumption. To generate enough electricity to treat 12,000 m3/day of water, using an electrodialysis reversal desalination plant, a 1.85 MWp FPV farm is proposed. The results indicate that this FPV farm would generate 3,005,828 kWh per year while avoiding the emission of 58,300 tons of CO2 and the evaporation of 159,950 m3 of water during its 25-year lifetime. Such systems allow higher renewable penetration in the energy mix and preserve the original use of the land.
An Effective Multi-Layer Attention Network for SAR Ship Detection
Authors: Suo Zhiling , Zhao Yongbo , Hu Yili
Published: April 2023

The use of deep learning-based techniques has improved the performance of synthetic aperture radar (SAR) image-based applications, such as ship detection. However, all existing methods have limited object detection performance under the conditions of varying ship sizes and complex background noise, to the best of our knowledge. In this paper, to solve both the multi-scale problem and the noisy background issues, we propose a multi-layer attention approach based on the thorough analysis of both location and semantic information. The solution works by exploring the richness of spatial information of the low-level feature maps generated by a backbone and the richness of semantic information of the high-level feature maps created by the same method. Additionally, we integrate an attention mechanism into the network to exclusively extract useful features from the input maps. Tests involving multiple SAR datasets show that our proposed solution enables significant improvements to the accuracy of ship detection regardless of vessel size and background complexity. Particularly for the widely-adopted High-Resolution SAR Images Dataset (HRSID), the new method provides a 1.3% improvement in the average precision for detection. The proposed new method can be potentially used in other feature-extraction-based classification, detection, and segmentation.
A Concept Study on Design Alternatives for Minimizing Accident Consequences in Maritime Autonomous Surface Ships
Authors: Lee Gyeong Joong , Lee Dongkon , Choi Jin , Kang Hee Jin
Published: April 2023

Autonomous ships, also known as maritime autonomous surface ships (MASS), are vessels that use artificial intelligence and robotics technologies to navigate independently. Due to their advanced technological capabilities, MASS is expected to play a significant role in the future of the shipping industry. The International Maritime Organization (IMO) is currently developing international standards for MASS classification, including accident avoidance technologies. However, the issue of how to mitigate the consequences of accidents involving autonomous ships has not been sufficiently addressed. Therefore, this study focuses on alternative design solutions and emergency response systems for MASS to properly control emergency situations and minimize the impact of accidents, such as flooding and fire on board. The goal is to efficiently address such accidents, especially in situations where the number of people on board is significantly reduced or the ship is being operated automatically or remotely, and to promptly detect and respond to such situations from a remote location. This paper investigates the possibility of modifying the design of the air conditioning system to delay flooding by considering a reduction in the number of crew members in order to prevent flooding. To prevent the spread of fire, the study examines early blockage measures for areas where air can enter. Flood and fire response systems were configured to be executed manually or automatically based on the results of presimulated scenarios defined in thousands of accident scenarios. Each accident propagation and response situation proposes an alternative using a coded shortcut key utilizing graphic symbols of international standard ISO 23120.
Tidal Stream Turbine Biofouling Detection and Estimation: A Review-Based Roadmap
Authors: Rashid Haroon , Benbouzid Mohamed , Titah-Benbouzid Hosna , Amirat Yassine , Mamoune Abdeslam
Published: April 2023

In the context of harvesting tidal stream energy, which is considered a promising source of renewable energy due to its high energy density, stability, and predictability, this paper proposes a review-based roadmap investigating the use of data-driven techniques, more specifically machine learning-based approaches, to detect and estimate the extent of biofouling in tidal stream turbines. An overview of biofouling and its impact on these turbines will be provided as well as a brief review of current methodologies and techniques for detecting and estimating biofouling. Additionally, recent developments and challenges in the field will be examined, while providing several promising prospects for biofouling detection and estimation in tidal stream turbines.
Error Evolutions and Analyses on Joint Effects of SST and SL via Intermediate Coupled Models and Conditional Nonlinear Optimal Perturbation Method
Authors: Mu Bin , Qin Xiaoyun , Yuan Shijin , Qin Bo
Published: April 2023

A seasonal predictability barrier has long been noticed in ENSO forecasting with numerical models. Previous studies explored the impact of seasonal optimal initial perturbation evolutions in sea surface temperature anomalies (SSTA) on ENSO forecasting using the intermediate coupled model (ICM) via the conditional nonlinear optimal perturbation (CNOP) method. In this paper, we investigate the joint effects of SSTA and sea level anomalies (SLA) from the perspective of the optimal growth initial error (OGE). After determining the four seasonal OGEs about SSTA and SLA (i.e., SSTA-OGE, SLA-OGE and Joint-OGE), we first demonstrate the patterns, evolutions and the resulting spring predictability barrier (SPB) of the above OGEs. Then, we analyze the mechanism of OGE evolutions and SPB. Finally, we conduct observing system simulation experiments to determine the best (economic) observation network. Our experimental results indicate that the ENSO evolution error induced by SSTA-OGE and Joint-OGE presents season dependency, but SLA-OGE has no impact on ENSO evolution. Moreover, Joint-OGEs induce error evolutions and the SPB with more significant intensity than SSTA-OGEs and SLA-OGEs. From mechanism analyses, the evolutions of SSTA-OGEs are mainly dominated by Bjerknes feedback. Further, the evolution dynamics of Joint-OGEs primarily contain the continuous heating between the upper ocean combined with Bjerknes feedback and thermal diffusion in response to the discharge process. In addition, comprehensive and economical sensitive areas are identified through Joint-OGE, including the central-eastern equatorial Pacific and the western and north-eastern tropical Pacific boundary, which contribute to the ENSO prediction benefits reaching 58.31% on average.
Scedosporium/Lomentospora Species Induce the Production of Siderophores by Pseudomonas aeruginosa in a Cystic Fibrosis Mimic Environment
Authors: Mello Thaís P. , Barcellos Iuri C. , Lackner Michaela , Branquinha Marta H. , Santos André L. S.
Published: April 2023

Over the last years, the interkingdom microbial interactions concerning bacteria and fungi cohabiting and/or responsible for human pathologies have been investigated. In this context, the Gram-negative bacterium Pseudomonas aeruginosa and fungal species belonging to the Scedosporium/Lomentospora genera are widespread, multidrug-resistant, emergent, opportunistic pathogens that are usually co-isolated in patients with cystic fibrosis. The available literature reports that P. aeruginosa can inhibit the in vitro growth of Scedosporium/Lomentospora species; however, the complex mechanisms behind this phenomenon are mostly unknown. In the present work, we have explored the inhibitory effect of bioactive molecules secreted by P. aeruginosa (3 mucoid and 3 non-mucoid strains) on S. apiospermum (n = 6 strains), S. minutisporum (n = 3), S. aurantiacum (n = 6) and L. prolificans (n = 6) under cultivation in a cystic fibrosis mimic environment. It is relevant to highlight that all bacterial and fungal strains used in the present study were recovered from cystic fibrosis patients. The growth of Scedosporium/Lomentospora species was negatively affected by the direct interaction with either mucoid or non-mucoid strains of P. aeruginosa. Moreover, the fungal growth was inhibited by the conditioned supernatants obtained from bacteria-fungi co-cultivations and by the conditioned supernatants from the bacterial pure cultures. The interaction with fungal cells induced the production of pyoverdine and pyochelin, 2 well-known siderophores, in 4/6 clinical strains of P. aeruginosa. The inhibitory effects of these four bacterial strains and their secreted molecules on fungal cells were partially reduced with the addition of 5-flucytosine, a classical repressor of pyoverdine and pyochelin production. In sum, our results demonstrated that distinct clinical strains of P. aeruginosa can behave differently towards Scedosporium/Lomentospora species, even when isolated from the same cystic fibrosis patient. Additionally, the production of siderophores by P. aeruginosa was induced when co-cultivated with Scedosporium/Lomentospora species, indicating competition for iron and deprivation of this essential nutrient, leading to fungal growth inhibition.
The Involvement of the Laccase Gene Cglac13 in Mycelial Growth, Germ Tube Development, and the Pathogenicity of Colletotrichum gloeosporioides from Mangoes
Authors: Zhang Mengting , Xiao Chunli , Tan Qing , Dong Lingling , Liu Xiaomei , Pu Jinji , Zhang He
Published: April 2023

Colletotrichum gloeosporioides is one of the most serious diseases that causes damage to mangoes. Laccase, a copper-containing polyphenol oxidase, has been reported in many species with different functions and activities, and fungal laccase could be closely related to mycelial growth, melanin and appressorium formation, pathogenicity, and so on. Therefore, what is the relationship between laccase and pathogenicity? Do laccase genes have different functions? In this experiment, the knockout mutant and complementary strain of Cglac13 were obtained through polyethylene glycol (PEG)-mediated protoplast transformation, which then determined the related phenotypes. The results showed that the knockout of Cglac13 significantly increased the germ tube formation, and the formation rates of appressoria significantly decreased, delaying the mycelial growth and lignin degradation and, ultimately, leading to a significant reduction in the pathogenicity in mango fruit. Furthermore, we observed that Cglac13 was involved in regulating the formation of germ tubes and appressoria, mycelial growth, lignin degradation, and pathogenicity of C. gloeosporioides. This study is the first to report that the function of laccase is related to the formation of germ tubes, and this provides new insights into the pathogenesis of laccase in C. gloeosporioides.