Vessel System Research Articles

Fuzzy Logic-Based Energy Management Strategy for Hybrid Fuel Cell Electric Ship Power and Propulsion System

The growing use of proton-exchange membrane fuel cells (PEMFCs) in hybrid propulsion systems is aimed at replacing traditional internal combustion engines and reducing greenhouse gas emissions. Effective power distribution between the fuel cell and the energy storage system (ESS) is crucial and has led to a growing emphasis on developing energy management systems (EMSs) to efficiently implement this integration. To address this goal, this study examines the performance of a fuzzy logic rule-based strategy for a hybrid fuel cell propulsion system in a small hydrogen-powered passenger vessel. The primary objective is to optimize fuel efficiency, with particular attention on reducing hydrogen consumption. The analysis is carried out under typical operating conditions encountered during a river trip. Comparisons between the proposed strategy with other approaches—control based, optimization based, and deterministic rule based—are conducted to verify the effectiveness of the proposed strategy. Simulation results indicated that the EMS based on fuzzy logic mechanisms was the most successful in reducing fuel consumption. The superior performance of this method stems from its ability to adaptively manage power distribution between the fuel cell and energy storage systems.

Biocompatibility evaluation and imaging application of a new fluorescent chemodosimeter for the specific detection of mercury ions in environmental and biological samples

Mercury is widely distributed in the natural environment and living environment, and as a heavy metal element with significant toxicity mercury ions pose a threat to agriculture and the food chain, thus consequently the residue and bioaccumulation of mercury ions will cause numerous and serious diseases, such as neurological abnormalities, gingivitis and tremor. Therefore, the development of a responsive and accurate fluorescent probe or sensor with excellent biocompatibility for mercury ions is crucial and marketable in the health and environmental protection. In this study, a novel fluorescent probe named BE-Hg has been innovatively proposed for the dynamic monitor of mercury ions. The probe showed excellent spectral performance in vitro experiments with detection limit as low as 1.18 nM, while it was applied to monitor environmental water samples with recovery as high as 93 %. Moreover, our group evaluated the probe safety using fluorescence-labeled tissue, organ and organ system including liver, heart, blood vessel and immune system in zebrafish for the first time. Note that the probe is proved with good biocompatibility by the cytotoxicity test, behavioral test, hepatotoxicity test, cardiotoxicity test, blood vessel toxicity test and immunotoxicity test with 15 indicators. In addition, the probe owns the ability to detect Hg2+ in live cells and zebrafish models. Thus it is expected to be a tool for the detection of mercury ions in water environments and organisms. In addition, behavioral test, hepatotoxicity test, cardiotoxicity test, blood vessel toxicity test and immunotoxicity test can be used to evaluate the biocompatibility of fluorescent probe, which provide a reliable safeguard for the research and development of probe.

Relationship Between Sodium Intake, Physical Activity and Stress with the Incidence of Hypertension in Pregnant Women at the Gununghalu Health Center 2023

Hypertension or high blood pressure refers to a condition where blood pressure in the blood vessel system continues to increase (World Health Organization, 2018). Gestational hypertension can have detrimental effects on the mother and fetus, and increase the risk of cardiovascular disease in the future. Women who have experienced preeclampsia or hypertension have higher health risks, including a 7- to 8-fold increased risk of death from coronary artery disease (Subki & et al, 2018). This study aims to investigate the correlation between factors that influence the incidence of hypertension in pregnant women in the area served by the Gununghalu Community Health Center. The research design used was case control, with a population of 1,473 people, where the sample consisted of pregnant women, including 63 of whom had hypertension. Data analysis was carried out using the Chi-Square method and multiple logistic regression analysis to identify factors that influence the incidence of hypertension. The research results show that there is a relationship between sodium consumption and hypertension in pregnant women showing a significance value of 0.007, indicating that there is a significant correlation between stress and the incidence of hypertension in pregnant women with a p value of 0.028. However, no significant relationship was found between physical activity and the incidence of hypertension in pregnant women, with a p value of 0.084. Multivariate analysis shows that sodium consumption is a risk factor for hypertension in pregnant women (p=0.004). It is hoped that all pregnant women will always have a pregnancy check-up with a health worker to avoid risks during pregnancy.

Ameliorative Review on Exploration of Spices in Aspects of Phytochemical Screening for their Antidiabetic Action

Diabetes is a diverse group of disorder characterized by hyperglycemia due to an deficiency in insulin production. Diabetes mellitus's chronic hyperglycemia is linked to end organ damage, dysfunction, and failure, including blood vessel, kidney, retina, and nervous system. With over 62 million cases of diabetes being identified in India, the disease is rapidly turning into a true epidemic. The majority of synthetic oral hypoglycemic medications available for the disease's treatment are costly, have significant adverse effects, and/or cannot be used while pregnant. As a result, a growing number of people worldwide are turning to traditional herbal remedies to prevent and treat diabetes. Spices having antioxidant, hypoglycemic, and hypolipidemic characteristics may be effective in the therapy of diabetes. As a result, these spices are growing in popularity due to their potential efficacy, little to nonexistent adverse effects, and synergistic effects. Spices are compounds used in food as coloring, flavoring, or preservation. They might be fresh or dried seeds, bark, roots, fruits, or even vegetables. This paper includes phytochemical screening of spices which have crucial role in the treatment of diabetis mellitus.

OPTIMALISASI KINERJA TRUK QUESTER CWE 370 MELALUI MODIFIKASI SISTEM VESSEL

The Quester CWE 370 truck is one of the most widely used transport vehicles in the industry, where reliability and operational efficiency are critical to ensuring a smooth supply chain. This research aims to optimize truck performance through vessel system modification, which focuses on improving fuel strength and efficiency. The modification process includes checking the raw material, cutting, welding, and smoothing, which is followed by testing to ensure fuel flow stability and better engine response. The results show that vessel system modifications not only improve fuel efficiency, but also extend engine life and reduce the need for routine maintenance. Thus, these modifications provide long-term benefits for the company in terms of operational cost savings and increased productivity.

Virtual prototype modeling and fuzzy control of the heave compensation system for a 500-ton deep-sea mining vessel

The unexpected heave motion of vessels generated by waves has always threatened the safe operation of mining vessels. The heave compensation system is a critical equipment for offshore cranes to ensure the safety and stability of the deep-sea mining vessel operation. Unfortunately, the nominal load of the mining vessel transporting minerals has become increasingly large, which has led to the dynamic performance of the heave compensation decline and a significant increase in energy consumption. To solve these problems, a semiactive heave compensation system and fuzzy logic-based controller are proposed in this paper. First, an active-passive hybrid heave compensation system is designed to reduce energy consumption greatly. The virtual prototype models of the proposed heave compensation system in a 500-ton deep-sea mining vessel are also built. Then, an adaptive tuning PID controller is developed based on the Transfer function of the heave compensation system and Mamdani-type fuzzy logic. Virtual prototype simulation results of AMESim-Simulink joint simulation illustrate that the accuracy of compensation for the four or six sea states reaches more than 90% with the proposed method and the power of the active compensation system is about 21% of the total power. Finally, the experimental results are included to demonstrate the effectiveness of the proposed semiactive heave compensation system.

Dynamic Characteristics Analysis of the DI-SO Cylindrical Spur Gear System Based on Meshing Conditions

The dual-input single-output (DI-SO) cylindrical spur gear system possesses advantages such as high load-carrying capacity, precise transmission, and low energy loss. It is increasingly becoming a core component of power transmission systems in maritime vessels, aerospace, marine engineering, and construction machinery. In practical operation, the stability of the DI-SO cylindrical spur gear system is influenced by complex excitations. These excitations lead to nonlinear vibration, meshing instability, and noise, which affect the performance and reliability of the entire equipment. Hence, the dynamic performance of the DI-SO cylindrical spur gear system is thoroughly investigated in this research. The impact of excitations and nonlinear factors on the dynamic characteristics was investigated comprehensively. A comparative analysis of the gear system was conducted by establishing a bending–torsional coupling vibration analysis model under synchronous and asynchronous meshing conditions. Nonlinear factors such as periodic time-varying meshing stiffness, meshing damping, friction coefficient, friction arms, load sharing ratio, comprehensive transmission error, and backlash were considered in the proposed model. Then, the effect laws of excitations and nonlinear factors such as meshing frequency, driving load fluctuation, backlash, and comprehensive transmission error were analyzed. The results indicate that the dynamic characteristics exhibited staged stable and unstable states under different meshing frequencies and meshing conditions. At the medium-frequency meshing stage (0.96 × 104~1.78 × 104 Hz), alternating phenomena of multi-periodic, quasi-periodic, and chaotic motion states were observed. Moreover, the root mean square value (RMS) of the dynamic transmission error (DTE) in the asynchronized gear system was generally higher than that in the synchronized gear system. It was found that selecting the appropriate meshing condition could effectively reduce the amplitude of the DTE. Additionally, the dynamic performance could be significantly improved by adjusting control parameters such as driving load fluctuation (0~179 N), backlash (0.8 × 10−4~0.9 × 10−4 m), and comprehensive transmission error (7.9 × 10−4~9.4 × 10−4 m). The research results provide a theoretical guidance for the design and optimization of the DI-SO cylindrical spur gear system.

Analysis of hybrid solutions with Li-ion battery system for DP-2 vessels

An economical approach for incorporating Battery Energy Storage Systems (BESS) onto DP-2 vessels is presented in this research. The paper deals with developing a Battery Optimization for Optimal Sizing and Throughput Energy Regulation (BOOSTER) framework for putting research findings into practice by optimizing battery size, technology choice and power generation scheduling while considering battery degradation. Twelve battery sizes are analyzed based on three key performance metrics: return on investment, payback period, and years of profitability. A Mixed Integer Linear Programming (MILP) is developed to operate the energy and power management system of the vessel in a fuel and economically efficient manner. The study considers two load profiles of a DP-2 vessel operating near Taiwan and the North Sea. Our findings emphasize the significance of taking battery ownership costs in the form of energy throughput cost and fuel price into account, resulting in a longer battery lifetime and higher return on investment. The research also proposes a BESS operation matrix that provides vessel operators with valuable information on BESS usage for economic benefits. This matrix translates analytics and decision-making into tangible actions that can be implemented in real-time operations. Based on the findings, energy systems may be optimized for a sustainable future, which benefits vessel operators and industry stakeholders.

Formation Control of a Multi-Unmanned Surface Vessel System: A Bibliometric Analysis

This study provides an overview of the literature on multi-unmanned surface vessel (multi-USV) systems, addressing the increasing attention on formation control of USVs due to their enhanced task execution ability, efficiency, and robustness in complex marine environments. Despite numerous studies on USVs covering fields, such as autonomous decision making, motion control, perception, and communication technologies, there is a significant lack of systematic literature review and bibliometric analysis specifically focused on a multi-USV system. This study aims to summarize advancements in multi-USV research, highlighting key aspects, including publication trends, influential scholars and papers, research hotspots, challenges, and future opportunities. By reviewing the current state of multi-USV research, this study contributes to the field as a beneficial reference for researchers, practitioners, and policymakers. It will not only highlight the progress made so far but also shed light on the gap that needs to be addressed to advance the field.

Experiment-based feasibility study of LNG equipment-embedded fuel gas supply system for vessels

This study introduces and validates an innovative Liquefied Natural Gas (LNG) Equipment-Embedded Fuel Gas Supply System (LEEF) designed for small LNG-fueled vessels. These ships face significant challenges in implementing LNG Fuel Gas Supply Systems (FGSS) owing to limited space and stringent regulatory requirements to reduce Greenhouse Gas (GHG) emissions. The LEEF system addresses these challenges by replacing the external Pressure Build-up Unit (PBU) with an integrated in-tank Electric PBU (EPBU) and vaporizer, enhancing spatial efficiency and safety while reducing LNG leakage risks. The experimental results indicate that the Pressure Rise Rate (PRR) accelerates with higher tank levels and increases the EPBU power. The PRR doubled at higher liquid levels and improved by 30–44 % with increased EPBU power at a constant liquid level. The EPBU effectively maintained the tank pressure against flow variations, achieving pressure control with minimal power. A review of international regulations and codes confirms that the EPBU satisfies explosion-proof standards and ensures stable operation. The LEEF system demonstrated substantial potential for application in small LNG-fueled ships by combining improved spatial efficiency and enhanced safety. This study contributes to the development of the FGSS solution that is more compact and safer compared to conventional systems, encouraging sustainable marine propulsion.

Blockchain-Based Cold Chain Traceability with NR-PBFT and IoV-IMS for Marine Fishery Vessels

Due to limited communication, computing resources, and unstable environments, traditional cold chain traceability systems are difficult to apply directly to marine cold chain traceability scenarios. Motivated by these challenges, we construct an improved blockchain-based cold chain traceability system for marine fishery vessels. Firstly, an Internet of Vessels system based on the Iridium Satellites (IoV-IMS) is proposed for marine cold chain monitoring. Aiming at the problems of low throughput, long transaction latency, and high communication overhead in traditional cold chain traceability systems, based on the Practical Byzantine Fault Tolerance (PBFT) consensus algorithm, a Node-grouped and Reputation-evaluated PBFT (NR-PBFT) is proposed to improve the reliability and robustness of blockchain system. In NR-PBFT, an improved node grouping scheme is designed, which introduces a consistent hashing algorithm to divide nodes into consensus and candidate sets, reducing the number of nodes participating in the consensus process, to lower communication overhead and transaction latency. Then, a reputation evaluation model is proposed to improve the node selection mechanism of NR-PBFT. It enhances the enthusiasm of nodes to participate in consensus, which considers the distance between fishery vessels, data size, and refrigeration temperature factors of nodes to increase throughput. Finally, we carried out experiments on marine fishery vessels, and the effectiveness of the cold chain traceability system and NR-PBFT were verified. Compared with PBFT, the transaction latency of NR-PBFT shortened by 81.92%, the throughput increased by 84.21%, and the communication overhead decreased by 89.4%.

Real Time Vessel Detection Model Using Deep Learning Algorithms for Controlling a Barrier System

This study addresses marine pollution caused by debris entering the ocean through rivers. A physical and bubble barrier system has been developed to collect debris, but an effective identification and classification system for incoming vessels is needed. This study evaluates the effectiveness of deep learning models in identifying and classifying vessels in real time. The YOLO (You Only Look Once) v5 and v8 models are evaluated for vessel detection and classification. A dataset of 624 images representing 13 different types of vessels was created to train the models. The YOLOv8, featuring a new backbone network, outperformed the YOLOv5 model, achieving a high mean average precision (mAP@50) of 98.9% and an F1 score of 91.6%. However, YOLOv8’s GPU consumption increased by 116% compared to YOLOv5. The advantage of the proposed method is evident in the precision–confidence curve (PCC), where the accuracy peaks at 1.00 and 0.937 confidence, and in the achieved frames per second (fps) value of 84.7. These findings have significant implications for the development and deployment of real-time marine pollution control technologies. This study demonstrates that YOLOv8, with its advanced backbone network, significantly improves vessel detection and classification performance over YOLOv5, albeit with higher GPU consumption. The high accuracy and efficiency of YOLOv8 make it a promising candidate for integration into marine pollution control systems, enabling real-time identification and monitoring of vessels. This advancement is crucial for enhancing the effectiveness of debris collection systems and mitigating marine pollution, highlighting the potential for deep learning models to contribute to environmental preservation efforts.

Modeling of Lithium-Flow Batteries with Aqueous Electrolyte

Flow batteries with aqueous electrolyte at the cathode are safe, low-cost and ecofriendly energy storage systems. When the aqueous cathode is coupled with a Li-metal anode with organic electrolyte, these batteries have extremely high energy densities (over 4,000 Wh/Kg), which makes them attractive not only for grid applications (where flow batteries are often used) but also in maritime applications such long endurance surface vessel systems and wave gliders [1-4]. In this presentation, we derive the mathematical model for lithium-flow batteries and use this model to predict the performance of the batteries under different discharge conditions, cathode microstructures, water flow velocities, etc. The results are then compared to experimental data already available in the literature. The mathematical model is based on coupling the flow equations (Navier-Stokes) with electrochemical equations for reaction rates and using average microscopic models for the cathode. For instance, Fig. 1 shows the voltage of a flow battery as a function of time for different water velocities in a flow battery simulated by solving the above model. For low water velocities, the water is not able to provide enough oxygen in the cathode and the voltage of the battery collapses after a few seconds. However, as long as the water velocity is above approx. 1.2 cm/s, the battery will have enough oxygen to operate continuously; in this case, the higher the flow of the water, the higher the voltage of the battery in the stationary state will be because of lower overpotential losses. In these simulations, the anode contained Li-metal. The cathode had a length of 1 cm (measured in the direction of water flow) and a thickness of 100 μm. The cell was discharged at a small rate of 0.01 mA/cm2. The incoming water had an oxygen concentration of 5 mg/l (which is equal to the oxygen concentration in seawater) and was pumped through the cathode at different velocities. A detailed derivation of the mathematical model and more simulation results and predictions will be presented at the meeting.

Development of a Porcine VCA Model Using an External Iliac Vessel-Based Vertical Rectus Abdominus Myocutaneous Flap.

Vascularized composite allotransplantation (VCA) involves transplanting a functional and anatomically complete tissue graft, such as a hand or face, from a deceased donor to a recipient. Although clinical VCA has resulted in successful outcomes, high rates of acute rejection and increased requirements for immunosuppression have led to significant long-term complications. Of note, immunosuppressed graft recipients are predisposed to infections, organ dysfunction, and malignancies. The long-term success of VCA grafts requires the discovery and implementation of unique approaches that avoid these complications altogether. Here, we describe our surgical technique and initial experience with a reproducible heterotopic porcine VCA model for the preclinical assessment of approaches to improve graft outcomes. Six heterotopic porcine allogeneic vertical rectus abdominis myocutaneous flap transplants were performed using Sinclair donors and Yucatan recipients. Immunosuppressive therapy was not used. Each flap was based on the left external iliac vessel system. Animals were followed postoperatively for surgery-related complications. The six pigs underwent successful VCA and were euthanized at the end of the study. Each flap demonstrated complete survival following vessel anastomosis. For the allogeneic recipients, on average, minimal erythema and healthy flap color were observed from postoperative days 1 to 4. There were no surgery-related animal deaths or complications. We have developed a reproducible, technically feasible heterotopic porcine VCA model based on the left external iliac vessel system. Our results demonstrate this model's potential to improve VCA graft outcomes by exploring tolerance induction and rejection biomarker discovery in preclinical studies.

Omnidirectional elastic constraint-based embedded 3D printing in non-yield stress fluids for engineering complex tissues

Embedded 3D printing, relying on yield-stress fluid-based supporting baths, has significantly expanded our ability to create complex tissues and organs. However, many extracellular matrix-based hydrogels, despite their excellent biological performance, such as gelatin and hyaluronic acid (HA) hydrogels, lack yield-stress properties, limiting their use in embedded 3D printing and hindering functional maturation of complex tissue constructs. To address this challenge, we present a method for embedded printing in non-yield stress fluids using sequential printing in a reversible ink template (SPIRIT) strategy. By leveraging an omnidirectional elastic constraint provided by conventional supporting baths, we can precisely fabricate GelMA and HAMA hydrogels into functional tissue constructs with both intricate external structures and internal vessel systems, which cannot be achieved with extant embedded printing techniques. As a proof of concept, we successfully printed a complex ventricle model with high cell density and internal channels using GelMA hydrogel, which demonstrated high cell viability and synchronous beating performance. The omnidirectional elastic constraint-based SPIRIT technique holds promise for advancing organ printing with remarkable structural complexities and biomaterials affinity akin to natural tissue constructs by decoupling from yield-stress fluids.

Flow structure of okra mucilage in rotating wall vessel system

The rotating-wall vessel (RWV) bioreactor, a 3D suspension culture system, faces challenges related to non-uniform tissue growth during the incubation of bone and heart tissues. Okra mucilage, an extract from okra pods with non-Newtonian rheological properties, has shown potential as a plasma replacement agent and has no induced cytotoxic effects. In this study, we investigated the flow structure of okra mucilage in rotating wall vessel system. By modifying the RWV and adding okra mucilage, we analyzed the flow structure using a high-speed camera and particle image velocimetry (PIV). Our results showed that okra mucilage creates a concentric circle-shaped rigid-like rotation at all rotation speeds (1-50 rpm). The high viscosity of okra mucilage resulted in a low terminal velocity for microparticles and quick response to rotational movements. These findings suggest that okra mucilage has the potential to enhance the uniformity of tissue growth in RWV systems by stabilizing the flow structure and reducing microparticle sedimentation.

Analysis of Double-Ended Guillotine Break Accident of Surge Line in ACP100 Based on Coupling Method: Development and Validation of the Coupling Method

The ACP100 is a small modular reactor (SMR) designed and built in China, featuring an integrated primary loop and passive safety systems. In SMRs, the interaction between the reactor coolant system, containment vessel, and other systems is highly interdependent. Therefore, it is necessary to use high-precision analysis codes, which can be achieved by coupling multiple codes. This paper is the first part of a study which investigates the LOCA in the ACP100 using a coupled platform. In this paper, a coupling platform was developed for transient analysis of SMR accidents, based on the system code NUSOL-SYS and the Integrated Severe Accident Analysis (ISAA) code. An inter-process communication module was developed adopting shared memory and event objects to exchange data between the two codes. A coupling interface defining the data to be exchanged was proposed. Both NUSOL-SYS and ISAA were modified to perform synchronous time step control. The coupling platform were validated through a hypothetical scenario and Edwards’ pipe blowdown experiment, demonstrating exact consistency and high accuracy. This coupling platform offers a new method for SMR accident analysis, providing a foundation for future work.

Connected FPSOs Thrive on Automation

Modern life is connected. Our computers, phones, and watches are all tapped into personal insights, from a daily planner to keep track of meetings and appointments to a health monitor tracking everything from heart rate to blood oxygen level in real time. This connectivity has bled over into many different facets of our lives, including work. Business and industry maintain critical connections allowing for simplification of complex tasks and the monitoring of machines for safety and performance. As the oil field has become more connected, increasing opportunities for automation have been introduced into both new and existing oilfield technologies with aims to achieve new levels of productivity and safety. Whether it is a robotic arm on the drill floor of a rig bringing pipe from the stand to the well or autonomous robots being used for inspections and other operation observations in hard-to-reach or remote places, if the connectivity is there it opens the door to a vast, new toolkit for contractors and operators alike. In 2023, a group of contractors came together to help define the next steps in automation for floating production, storage, and offloading (FPSO) vessels. The FPSO Coalition—made up of SLB, Rockwell Automation, Sensia, and Cognite—is a collaboration designed to accelerate the evolution of FPSOs by developing and employing new digital capabilities aimed at improving the reliability, availability, safety, and efficiency of the assets, while lowering the carbon footprint of their offshore operations. FPSOs have been invaluable tools for offshore development around the world for decades. Some older hardware does not have the benefit of being wired for connection or pieces of equipment being Internet of Things (IoT)-ready. As much as the coalition looks to solutions to integrate into new facilities, it also explores the limitations and potential for bringing older yet still viable components into the digital age. Under the venture, SLB was tapped to bring advanced digital solutions, subsurface domain expertise, and complex integration and project management capabilities to scale up efficiencies and lower the carbon footprint of operations across every stage of the FPSO life cycle. Rockwell would provide expertise in control and safety systems for FPSOs, as well as extensive experience in power systems. “Keeping in mind that the typical operating life of an FPSO can be 20-25-30 years, a lot can change in terms of technology, process conditions, regulatory requirements, etc.,” said Greg Trostel, global industry development manager for floating production at Rockwell Automation. “But ultimately, the main goal of automation is to ensure the reliable and safe operation of the vessel—no loss of containment, no personnel at risk, no environmental incidents. “Ideally, automation systems can adapt and grow with the changing technology and changing requirements. We depend on the automation systems to keep all the individual process modules connected to, and operating in concert with, the main vessel systems,” he said. One of the first things tasked to the coalition was a contract awarded to SLB for a multipurpose dynamic simulation solution providing an immersive digital twin environment to dynamically simulate operational processes and their control and automation systems, train personnel, and strengthen safety elements at five newbuild FPSO units to be installed in Búzios Field in the Santos Basin for Petrobras.

Streamlining large-scale oceanic biomonitoring using passive eDNA samplers integrated into vessel's continuous pump underway seawater systems

Passive samplers are enabling the scaling of environmental DNA (eDNA) biomonitoring in our oceans, by circumventing the time-consuming process of water filtration. Designing a novel passive sampler that does not require extensive sample handling time and can be connected to ocean-going vessels without impeding normal underway activities has potential to rapidly upscale global biomonitoring efforts onboard the world's oceanic fleet. Here, we demonstrate the utility of an artificial sponge sampler connected to the continuous pump underway seawater system as a means to enable oceanic biomonitoring. We compared the performance of this passive sampling protocol with standard water filtration at six locations during a research voyage from New Zealand to Antarctica in early 2023. Eukaryote metabarcoding of the mitochondrial COI gene revealed no significant difference in phylogenetic α-diversity between sampling methods and both methods delineated a progressive reduction in number of Zero-Radius Operational Taxonomic Units (ZOTUs) with increased latitudes. While both sampling methods revealed comparable trends in geographical community compositions, distinct clusters were identified for passive samplers and water filtration at each location. Additionally, greater variability between replicates was observed for passive samplers, resulting in an increased estimated level of replication needed to recover 90 % of the biodiversity. Furthermore, traditional water filtration failed to detect three phyla observed by passive samplers and extrapolation analysis estimated passive samplers recover a larger number of ZOTUs compared to water filtration for all six locations. Our results demonstrate the potential of this passive eDNA sampler protocol and highlight areas where this emerging technology could be improved, thereby enabling large-scale offshore marine eDNA biomonitoring by leveraging the world's oceanic fleet without interfering with onboard activities.

Effect of regular winter swimming on blood morphological, rheological, and biochemical indicators and activity of antioxidant enzymes in males

BackgroundExposure of the human body to cold water triggers numerous beneficial physiological changes. The study aimed to assess the impact of regular winter swimming on blood morphological, rheological, and biochemical indicators and activity of antioxidant enzymes in males.MethodsThe study involved 10 male winter swimmers (the same participants examined before the season and after the season) and 13 males (not winter swimming, leading a sedentary lifestyle) in the control group. Fasting blood was collected twice: in November and in March of the following year. Basic blood morphological indicators, red cell elongation index (EI) and aggregation index (AI), concentrations of testosterone, cortisol, urea, and creatinine, as well as plasma activity of antioxidant enzymes of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were determined.ResultsThe data were collected from the same winter swimmers at the beginning and end of the season. Winter swimming resulted in a significant increase of EI values at a shear stress of 0.30 (p = 0.40), 0.58 (p < 0.001), 4.24 (p = 0.021), 8.23 (p = 0.001), 15.59 (p = 0.001), 30.94 (p = 0.004), and 60.00 Pa (p = 0.043); haemoglobin was lower than before the season (p < 0.027). No significant changes were observed in AI, AMP, T1/2, the levels of urea, creatinine, eGFR, testosterone, cortisol, or the activity of CAT or SOD. There was a statistically significant increase in GPx activity (p = 0.014) and increase in testosterone concentration (p = 0.035) in the group of winter swimmers examined before the season as compared with the control group. No statistically significant differences were found for the mean values of blood morphological indicators and other parameters.ConclusionsWinter swimming can prove to be a health-promoting factor in males, as indicated by a rise in the deformability of red blood cells in the blood vessel system after a full season of winter swimming, leading to better body oxygenation, and improves the antioxidant defence and testosterone concentration (within standard limits) in the group of winter swimmers examined before the season as compared with the control group. Winter swimming helps maintain appropriate levels of blood rheological indicators, urea, creatinine, eGFR, cortisol, testosterone, and activity of antioxidant enzymes.Trial registrationClinicalTrials.gov identifier NCT06223087, 15.01.2024.