Disinfection of swimming pool water is critical to ensure the safety of the recreational activity for swimmers.However,swimming pools have a constant loading of organic matter from input water and anthropogenic contam...Disinfection of swimming pool water is critical to ensure the safety of the recreational activity for swimmers.However,swimming pools have a constant loading of organic matter from input water and anthropogenic contamination,leading to elevated levels of disinfection byproducts(DBPs).Epidemiological studies have associated increased risks of adverse health effects with frequent exposure to DBPs in swimming pools.Zhang et al.(2023b)investigated the occurrence of trihalomethanes(THMs),haloacetic acids(HAAs),haloacetonitriles(HANs),and haloacetaldehydes(HALs)in eight swimming pools and the corresponding input water in a city in Eastern China.The concentrations of THMs,HAAs,HANs,and HALs in swimming poolswere 1–2 orders of magnitude higher than those detected in the input water.The total lifetime cancer and non-cancer health risks of swimmers through oral,dermal,inhalation,buccal,and aural exposure pathways were assessed using the United States Environmental Protection Agency’s(USEPA)standard model and Swimmer Exposure Assessment Model(SWIMODEL).The results showed that dermal and inhalation pathways were the most significant for the associated cancer and non-cancer risks.This article provides an overview and perspectives of DBPs in swimming pools,the benefits of swimming,the need to improve the monitoring of DBPs,and the importance of swimmers’hygiene practices to keep swimming pools clean.The benefits of swimming outweigh the risks from DBP exposure for the promotion of public health.展开更多
Fish swimming hydrodynamics serves as a critical foundation for aquatic ecological conservation,with recent research extending from 2D to 3D perspectives.This study employs 3D high-fidelity modeling with dynamic mesh ...Fish swimming hydrodynamics serves as a critical foundation for aquatic ecological conservation,with recent research extending from 2D to 3D perspectives.This study employs 3D high-fidelity modeling with dynamic mesh technology to investigate how cylindrical obstacles at varying positions affect Carassius auratus locomotion.Analysis of nine configurations reveals bidirectional flow interactions between fish and cylinders,with cylinder wake influence persisting at 1-2 times the total length intervals but diminishing at 3times.Compared with swimming in uniform flow,the mechanical benefit of C.auratus located 2 times the total length directly behind the cylinder is the largest,and its value reaches 4.19 times.Wavelet analysis of 30-cycle mechanical data demonstrates closer intervals enhance benefit magnitude,whereas greater distances accelerate benefit realization.These 3D computational findings corroborate 2D studies while providing new spatial interaction insights,offering theoretical foundations for fish conservation strategies related to hydraulic structures.展开更多
Deep-sea aquaculture is an emerging trend due to the contamination and overexploitation of nearshore mariculture areas.However,the complex water conditions in the deep sea impose higher demands on the swimming perform...Deep-sea aquaculture is an emerging trend due to the contamination and overexploitation of nearshore mariculture areas.However,the complex water conditions in the deep sea impose higher demands on the swimming performance of farmed animals.Spotted sea bass(Lateolabrax maculatus)is one of the most economically important fish species in China.To investigate the mechanisms underlying the individual variations in swimming performance among spotted sea bass,we measured their critical swimming speed(U_(crit))and morphological phenotypes.Total length,body length,body weight,caudal region length,and condition factor showed significant positive correlations with absolute Ucrit.In contrast,caudal fin length and pectoral fin length tended to hinder the swimming performance of individual spotted sea bass.Additionally,white muscle tissues from fish exhibiting good swimming performance(relative U_(crit)>8.20 BL/s)and poor swimming performance(relative U_(crit)<7.31 BL/s)were sampled for RNA-seq.A total of 694 differential expression genes(DEGs)were identified through gene expression analysis,with significant enrichment in GO terms such as mitochondrial protein complex,ribosomal subunit,structural constituent of ribosome,and oxidative phosphorylation,as well as genes in KEGG pathways including ribosome and metabolic pathways.In conclusion,our study for the first time comprehensively elucidated the impact of morphology of spotted sea bass on its individual differences in swimming ability,and analyzed the genetic basis underlying swimming ability using transcriptomic methods.This study provides a theoretical basis for the potential breeding varieties of spotted sea bass suitable for deep-sea aquaculture.展开更多
The role of hydrodynamic effect in the meeting of multiple fish is a fascinating topic.The interactions of two self-propelled flexi-ble plates swimming in opposite directions horizontally and maintaining a certain lat...The role of hydrodynamic effect in the meeting of multiple fish is a fascinating topic.The interactions of two self-propelled flexi-ble plates swimming in opposite directions horizontally and maintaining a certain lateral distance are numerically simulated using a penalty-immersed boundary method.The effects of the flapping phase and lateral distance on the propulsive performance of two fish meetings are analyzed.Results show that,when two plates meet,if their leading edges diverge laterally,the individual plate can efficiently and rapidly move apart from the other horizontally.If their leading edges converge laterally,the plate motion can be retarded,leading to high energy consumption.Moreover,an increasing lateral distance between two plates significantly weakens the fluid-structure interactions,resulting in an exponential decline in mean cruising speed.A quantitative force analysis based on vortex dynamic theory is performed to gain physics insight into the hydrodynamic interaction mechanism.It is found that lateral separation between the two leading edges enhances the vorticity generation and boundary vorticity flux on the surface of the plate,subsequently reinforcing the thrust effect and increasing horizontal velocity.This study offers insight into the hydro-dynamic mechanisms of the fluid-structure interactions among fish moving toward each other and suggests potential strategies for enhancing the maneuverability of robotic fish in complex environment.展开更多
Numerical simulation and control of self- propelled swimming of two- and three-dimensional biomimetic fish school in a viscous flow are investigated. With a parallel computational fluid dynamics package for the two- a...Numerical simulation and control of self- propelled swimming of two- and three-dimensional biomimetic fish school in a viscous flow are investigated. With a parallel computational fluid dynamics package for the two- and three-dimensional moving boundary problem, which combines the adaptive multi-grid finite volume method and the methods of immersed boundary and volume of fluid, it is found that due to the interactions of vortices in the wakes, without proper control, a fish school swim with a given flap- ping rule can not keep the fixed shape of a queue. In order to understand the secret of fish swimming, a new feedback con- trol strategy of fish motion is proposed for the first time, i,e., the locomotion speed is adjusted by the flapping frequency of the caudal, and the direction of swimming is controlled by the swinging of the head of a fish. Results show that with this feedback control strategy, a fish school can keep the good order of a queue in cruising, turning or swimming around circles. This new control strategy, which separates the speed control and direction control, is important in the construction of biomimetic robot fish, with which it greatly simplifies the control devices of a biomimetic robot fish.展开更多
Fish have a remarkable amount of variation in their swimming performance, from within species dif- ferences to diversity among major taxonomic groups. Fish swimming is a complex, integrative phenotype and has the abil...Fish have a remarkable amount of variation in their swimming performance, from within species dif- ferences to diversity among major taxonomic groups. Fish swimming is a complex, integrative phenotype and has the ability to plastically respond to a myriad of environmental changes. The plasticity of fish swimming has been observed on whole-organismal traits such as burst speed or critical swimming speed, as well as underlying phenotypes such as muscle fiber types, kinematics, cardiovascular system, and neuronal processes. Whether the plastic responses of fish swimming are beneficial seems to depend on the environmental variable that is changing. For example, because of the effects of temperature on biochemical processes, alterations of fish swimming in response to tem- perature do not seem to be beneficial. In contrast, changes in fish swimming in response to variation in flow may benefit the fish to maintain position in the water column. In this paper, we examine how this plasticity in fish swimming might evolve, focusing on environmental variables that have received the most attention： temperature, habitat, dissolved oxygen, and carbon dioxide variation. Using examples from previous research, we highlight many of the ways fish swimming can plastic- ally respond to environmental variation and discuss potential avenues of future research aimed at understanding how plasticity of fish swimming might evolve. We consider the direct and indirect ef- fects of environmental variation on swimming performance, including changes in swimming kine- matics and suborganismal traits thought to predict swimming performance. We also discuss the role of the evolution of plasticity in shaping macroevolutionary patterns of diversity in fish swimming.展开更多
The three-dimensional lattice Boltzmann method(LBM)is used to simulate the motion of a spherical squirmer in a square tube,and the steady motion velocity of a squirmer with different Reynolds numbers(Re,ranging from 0...The three-dimensional lattice Boltzmann method(LBM)is used to simulate the motion of a spherical squirmer in a square tube,and the steady motion velocity of a squirmer with different Reynolds numbers(Re,ranging from 0.1 to 2)and swimming types is investigated and analyzed to better understand the swimming characteristics of microorganisms in different environments.First,as the Reynolds number increases,the effect of the inertial forces becomes significant,disrupting the squirmer's ability to maintain its theoretical velocity.Specifically,as the Reynolds number increases,the structure of the flow field around the squirmer changes,affecting its velocity of motion.Notably,the swimming velocity of the squirmer exhibits a quadratic relationship with the type of swimming and the Reynolds number.Second,the narrow tube exerts a significant inhibitory effect on the squirmer motion.In addition,although chirality does not directly affect the swimming velocity of the squirmer,it can indirectly affect the velocity by changing its motion mode.展开更多
Hydrodynamic force is an important factor that affects the performance of underwater vehicle.Adapting to the current underwater environment by changing its shape is an important feature of underwater snake-like robots...Hydrodynamic force is an important factor that affects the performance of underwater vehicle.Adapting to the current underwater environment by changing its shape is an important feature of underwater snake-like robots(USLR).An experiment was implemented to verify the swimming along the straight line of USLR.A simulation platform is also established for the analysis of the swimming of USLR.To figure out adaptive swimming of USLR to different underwater environments,the relationships between CPG parameters and maximum swimming speed have been discussed,and the switching between different swimming modes has been implemented.展开更多
We investigated the concentration of trihalomethanes （THMs） in tap water and swimming pool water in the area of the Nakhon Path- om Municipality during the period April 2005-March 2006. The concentrations of total T...We investigated the concentration of trihalomethanes （THMs） in tap water and swimming pool water in the area of the Nakhon Path- om Municipality during the period April 2005-March 2006. The concentrations of total THMs, chloroform, bromodichloromethane, dibromochloromethane and bromoform in tap water were 12.70-41.74, 6.72-29.19, 1.12-11.75, 0.63-3.55 and 0.08-3.40 μg/L, respectively, whereas those in swimming pool water were 26.15-65.09, 9.50-36.97, 8.90-18.01, 5.19-22.78 and ND-6.56 μg/L, respectively. It implied that the concentration of THMs in swimming pool water was higher than those in tap water, particularly, brominated-THMs. Both tap water and swimming pool water contained concentrations of total THMs below the standards of the World Health Organization （WHO）, European Union （EU） and the United States Environmental Protection Agency （USEPA） phase Ⅰ, but 1 out of 60 tap water samples and 60 out of 72 swimming pool water samples contained those over the Standard of the USEPA phase Ⅱ. From the two cases of cancer risk assessment including Case Ⅰ Non-Swimmer and Case Ⅱ Swimmer, assessment of cancer risk of nonswimmers from exposure to THMs at the highest and the average concentrations was 4.43×10^-5 and 2.19×10^-5, respectively, which can be classified as acceptable risk according to the Standard of USEPA. Assessment of cancer risk of swimmers from exposure to THMs at the highest and the average concentrations was 1.47×10^-3 and 7.99×10^-4, respectively, which can be classified as unacceptable risk and needs to be improved. Risk of THMs exposure from swimming was 93.9%-94.2% of the total risk. Cancer risk of THMs concluded from various routes in descending order was： skin exposure while swimming, gastro-intestinal exposure from tap water intake, and skin exposure to tap water and gastro-intestinal exposure while swimming. Cancer risk from skin exposure while swimming was 94.18% of the total cancer risk.展开更多
There are many kinds of swimming mode in the fish world, and we investigated two of them, used by cyprinids and bulltrout. In this paper we track the locomotion locus by marks in different flow velocity from 0.2 m...There are many kinds of swimming mode in the fish world, and we investigated two of them, used by cyprinids and bulltrout. In this paper we track the locomotion locus by marks in different flow velocity from 0.2 m·s^-1 to 0.8 m·s^-1. By fit the data above we could find out the locomotion mechanism of the two kinds of fish and generate a mathematical model of fish kine- matics. The cyprinid fish has a greater oscillation period and amplitude compared with the bulltrout, and the bulltrout changes velocity mainly by controlling frequency of oscillation.展开更多
Polybrominated diphenyl ethers（PBDEs） are new kinds of persistent organic pollutants（POPs） and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Her...Polybrominated diphenyl ethers（PBDEs） are new kinds of persistent organic pollutants（POPs） and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE（BDE-47）and deca-BDE（BDE-209） were applied, and their toxic effects on the swimming behavior,population growth and reproduction of Brachionus plicatilis were investigated. The results showed that：（1） The actual concentrations of BDE-47 and-209 in the seawater phase measured by GC–MS（Gas Chromatography-Mass Spectrometer） were much lower than their nominal concentrations.（2） In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209.（3） Both BDE-47 and-209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females（OF/NOF）, the ratio of mictic females/amictic females（MF/AF）, resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and-209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.展开更多
The potential risks of perfluorooctane sulfonate （PFOS） are of increasing ecological concern. Swimming performance is linked to the fitness and health of fish. However, the impacts of PFOS on swimming performance re...The potential risks of perfluorooctane sulfonate （PFOS） are of increasing ecological concern. Swimming performance is linked to the fitness and health of fish. However, the impacts of PFOS on swimming performance remain largely unknown. We investigated the ecotoxicological effects of acute exposure to PFOS on the swimming performance and energy expenditure of juvenile goldfish （Carassius auratus）. The fish were exposed to a range of PFOS concentrations （0, 0.5, 2, 8 and 32 mg/L） for 48 hr. The spontaneous swimming activity, fast-start swimming performance, critical swimming speed （Ucrit） and active metabolic rate （AMR） of the goldfish were examined after exposure to PFOS. PFOS exposure resulted in remarkable effects on spontaneous activity. Motion distance was reduced, and the proportion of motionless time increased with increasing concentrations of PFOS. However, no significant alterations in the fast-start performance-related kinematic parameters, such as latency time, maximum linear velocity, maximum linear acceleration or escape distance during the first 120 msec after stimulus, were observed after PFOS exposure. Unexpectedly, although PFOS exposure had marked influences on the swimming oxygen consumption rates and AMR of goldfish, the U crit of the goldfish was not significantly affected by PFOS. This may result in a noteworthy increase in the energetic cost of transport. The overall results indicate that, in contrast to spontaneous activity, underlying swimming capabilities are maintained in goldfish after short-term exposure to PFOS, but energy expenditure during the process of swimming is dramatically aggravated.展开更多
Energy metabolism fuels swimming and other biological processes.We compared the swimming performance and energy metabolism within and across eight freshwater fish species.Using swim tunnel respirometers,we measured th...Energy metabolism fuels swimming and other biological processes.We compared the swimming performance and energy metabolism within and across eight freshwater fish species.Using swim tunnel respirometers,we measured the standard metabolic rate(SMR)and maximum metabolic rate(MMR)and calculated the critical swimming speed(Ucrit).We accounted for body size,metabolic traits,and some morphometric ratios in an effort to understand the extent and underlying causes of variation.Body mass was largely the best predictor of swimming capacity and metabolic traits within species.Moreover,we found that predictive models using total length or SMR,in addition to body mass,signicantly in creased the explained variation of Ucrit and MMR in certain fish species.These predictive models also underlined that,once body mass has been accounted for,Ucrit can be independently affected by total length or MMR.This study exemplifies the utility of multiple regression models to assess within-species variability.At interspecific level,our results showed that variation in UcriX can partly be explained by the variation in the interrelated traits of MMR,finen ess,and muscle ratios.Among the species studied,bleak Al burn us alburnus performed best in terms of swimming performance and efficiency.By contrast,pumpkinseed Lepomis gibbosus showed very poor swimming performance,but attained lower mass-specific cost of transport(MCOT)than some rheophilic species,possibly reflecting a cost reduction strategy to compensate for hydrod yn amic disadvantages.In con elusion,this study provides insight into the key factors in fluenci ng the swimming performa nee of fish at both intra-and in terspecific levels.展开更多
Background:Vascular cognitive impairment caused by chronic cerebral hypoperfusion(CCH)has become a hot issue worldwide.Aerobic exercise positively contributes to the preservation or restoration of cognitive abilities;...Background:Vascular cognitive impairment caused by chronic cerebral hypoperfusion(CCH)has become a hot issue worldwide.Aerobic exercise positively contributes to the preservation or restoration of cognitive abilities;however,the specific mechanism has remained inconclusive.And recent studies found that neurogranin(Ng)is a potential biomarker for cognitive impairment.This study aims to investigate the underlying role of Ng in swimming training to improve cognitive impairment.Methods:To test this hypothesis,the clustered regularly interspaced short palindromic repeats(CRISPR)-associated protein 9(Cas9)system was utilized to construct a strain of Ng conditional knockout(Ng cKO)mice,and bilateral common carotid artery stenosis(BCAS)surgery was performed to prepare the model.In Experiment 1,2-month-old male and female transgenic mice were divided into a control group(wild-type littermate,n=9)and a Ng cKO group(n=9).Then,2-month-old male and female C57BL/6 mice were divided into a sham group(C57BL/6,n=12)and a BCAS group(n=12).In Experiment 2,2-month-old male and female mice were divided into a sham group(wild-type littermate,n=12),BCAS group(n=12),swim group(n=12),BCAS+Ng cKO group(n=12),and swim+Ng cKO group(n=12).Then,7 days after BCAS,mice were given swimming training for 5 weeks(1 week for adaptation and 4 weeks for training,5 days a week,60 min a day).After intervention,laser speckle was used to detect cerebral blood perfusion in the mice,and the T maze and Morris water maze were adopted to test their spatial memory.Furthermore,electrophysiology and Western blotting were conducted to record long-term potential and observe the expressions of Ca^(2+)pathway-related proteins,respectively.Immunohistochemistry was applied to analyze the expression of relevant markers in neuronal damage,inflammation,and white matter injury.Results:The figures showed that spatial memory impairment was detected in Ng cKO mice,and a sharp decline of cerebral blood flow and an impairment of progressive spatial memory were observed in BCAS mice.Regular swimming training improved the spatial memory impairment of BCAS mice.This was achieved by preventing long-term potential damage and reversing the decline of Ca^(2+)signal transduction pathway-related proteins.At the same time,the results suggested that swimming also led to improvements in neuronal death,inflammation,and white matter injury induced by CCH.Further study adopted the use of Ng cKO transgenic mice,and the results indicated that the positive effects of swimming training on cognitive impairments,synaptic plasticity,and related pathological changes caused by CCH could be abolished by the knockout of Ng.Conclusion:Swimming training can mediate the expression of Ng to enhance hippocampal synaptic plasticity and improve related pathological changes induced by CCH,thereby ameliorating the spatial memory impairment of vascular cognitive impairment.展开更多
Disinfection by-products(DBPs)are formed in swimming pools by the reactions of bather inputs with the disinfectant.Although a wide range of molecules has been identified within DBPs,only few kinetic rates have been re...Disinfection by-products(DBPs)are formed in swimming pools by the reactions of bather inputs with the disinfectant.Although a wide range of molecules has been identified within DBPs,only few kinetic rates have been reported.This study investigates the kinetics of chlorine consumption,chloroform formation and dichloroacetonitrile formation caused by human releases.Since the flux and main components of human inputs have been determined and formalized through Body Fluid Analogs(BFAs),it is possible to model the DBPs formation kinetics by studying a limited number of precursor molecules.For each parameter the individual contributions of BFA components have been quantified and kinetic rates have been determined,based on reaction mechanisms proposed in the literature.With a molar consumption of 4 mol Cl2/mol,urea is confirmed as the major chlorine consumer in the BFA because of its high concentration in human releases.The higher reactivity of ammonia is however highlighted.Citric acid is responsible for most of the chloroform produced during BFA chlorination.Chloroform formation is relatively slow with a limiting rate constant determined at 5.50×10^-3 L/mol/sec.L-histidine is the only precursor for dichloroacetonitrile in the BFA.This DBP is rapidly formed and its degradation by hydrolysis and by reaction with hypochlorite shortens its lifetime in the basin.Reaction rates of dichloroacetonitrile formation by L-histidine chlorination have been established based on the latest chlorination mechanisms proposed.Moreover,this study shows that the reactivity toward chlorine differs whether L-histidine is isolated or mixed with BFA components.展开更多
Inspired by the simple yet amazing morphology of the Octopus, we propose the design, fabrication, and characterization of multi-material bio-inspired soft Octopus robot (Octobot). 3D printed molds for tentacles and he...Inspired by the simple yet amazing morphology of the Octopus, we propose the design, fabrication, and characterization of multi-material bio-inspired soft Octopus robot (Octobot). 3D printed molds for tentacles and head were used. The tentacles of the Octobot were casted using Ecoflex-0030 while head was fabricated using relatively flexible material, i.e., OOMOO-25. The head is attached to the functionally responsive tentacles (each tentacle is of 79.12 mm length and 7 void space diameter), whereas Shape Memory Alloy (SMA) muscle wires of 0.5 mm thickness are used in Octobot tentacles for dual thrust generation and actuation of Octobot. The tentacles were separated in two groups and were synchronously actuated. Each tentacle of the developed Octobot contains a pair of SMA muscles (SMA-α and SMA-β). SMA-α muscles being the main actuator, was powered by 9 V, 350 mA power supply, whereas SMA-β was used to provide back thrust and thus helps to increase the actuation frequency. Simulation work of the proposed model was performed in the SolidWorks environment to verify the vertical velocity using the octopus tentacle actuation. The design morphology of Octobot was optimized using simulation and TRACKER software by analyzing the experimental data of angle, displacement, and velocity of real octopus. The as-developed Octobot can swim at variable frequencies (0.5–2 Hz) with the average speed of 25 mm/s (0.5 BLS). Therefore, the proposed soft Octopus robot showed an excellent capability of mimicking the gait pattern of its natural counterpart.展开更多
This study was conducted to evaluate the effects of dietary lipid sources on the growth performance and fatty acid composition of the swimming crab, P ortunus trituberculatus. Four isonitrogenous and isoenergetic expe...This study was conducted to evaluate the effects of dietary lipid sources on the growth performance and fatty acid composition of the swimming crab, P ortunus trituberculatus. Four isonitrogenous and isoenergetic experimental diets were formulated to contain four separate lipid sources, including fish, soybean, rapeseed, and linseed oils(FO, SO, RO, and LO, respectively). With three replicates of 18 crabs each for each diet, crabs(initial body weight, 17.00 ±0.09 g) were fed twice daily for 8 weeks. There were no significant differences among these groups in terms of weight gain, specific growth rate, and hepatosomatic index. However, the RO groups' survival rate was significantly lower than FO groups. The feed conversion and protein efficiency ratios of RO groups were poorer than other groups. The proximate compositions of whole body and hepatopancreas were significantly affected by these dietary treatments. Tissue fatty acid composition mainly reflected dietary fatty acid compositions. Crabs fed FO diets exhibited significantly higher arachidonic, eicosapentaenoic, and docosahexaenoic acid contents in muscle and hepatopancreas compared with VO crabs. Linoleic, oleic, and linolenic acids in muscle and hepatopancreas were the highest in the SO, RO, and LO groups, respectively. The present study suggested that SO and LO could substitute for FO in fishmeal-based diets for swimming crabs, without affecting growth performance and survival.展开更多
文摘Disinfection of swimming pool water is critical to ensure the safety of the recreational activity for swimmers.However,swimming pools have a constant loading of organic matter from input water and anthropogenic contamination,leading to elevated levels of disinfection byproducts(DBPs).Epidemiological studies have associated increased risks of adverse health effects with frequent exposure to DBPs in swimming pools.Zhang et al.(2023b)investigated the occurrence of trihalomethanes(THMs),haloacetic acids(HAAs),haloacetonitriles(HANs),and haloacetaldehydes(HALs)in eight swimming pools and the corresponding input water in a city in Eastern China.The concentrations of THMs,HAAs,HANs,and HALs in swimming poolswere 1–2 orders of magnitude higher than those detected in the input water.The total lifetime cancer and non-cancer health risks of swimmers through oral,dermal,inhalation,buccal,and aural exposure pathways were assessed using the United States Environmental Protection Agency’s(USEPA)standard model and Swimmer Exposure Assessment Model(SWIMODEL).The results showed that dermal and inhalation pathways were the most significant for the associated cancer and non-cancer risks.This article provides an overview and perspectives of DBPs in swimming pools,the benefits of swimming,the need to improve the monitoring of DBPs,and the importance of swimmers’hygiene practices to keep swimming pools clean.The benefits of swimming outweigh the risks from DBP exposure for the promotion of public health.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFC3204202National Natural Science Foundation of China,Grant/Award Number:52122904Ministry of Water Resources,Grant/Award Number:SKS-2022121。
文摘Fish swimming hydrodynamics serves as a critical foundation for aquatic ecological conservation,with recent research extending from 2D to 3D perspectives.This study employs 3D high-fidelity modeling with dynamic mesh technology to investigate how cylindrical obstacles at varying positions affect Carassius auratus locomotion.Analysis of nine configurations reveals bidirectional flow interactions between fish and cylinders,with cylinder wake influence persisting at 1-2 times the total length intervals but diminishing at 3times.Compared with swimming in uniform flow,the mechanical benefit of C.auratus located 2 times the total length directly behind the cylinder is the largest,and its value reaches 4.19 times.Wavelet analysis of 30-cycle mechanical data demonstrates closer intervals enhance benefit magnitude,whereas greater distances accelerate benefit realization.These 3D computational findings corroborate 2D studies while providing new spatial interaction insights,offering theoretical foundations for fish conservation strategies related to hydraulic structures.
基金National Key R&D Program of China(No.2022YFD2400103).
文摘Deep-sea aquaculture is an emerging trend due to the contamination and overexploitation of nearshore mariculture areas.However,the complex water conditions in the deep sea impose higher demands on the swimming performance of farmed animals.Spotted sea bass(Lateolabrax maculatus)is one of the most economically important fish species in China.To investigate the mechanisms underlying the individual variations in swimming performance among spotted sea bass,we measured their critical swimming speed(U_(crit))and morphological phenotypes.Total length,body length,body weight,caudal region length,and condition factor showed significant positive correlations with absolute Ucrit.In contrast,caudal fin length and pectoral fin length tended to hinder the swimming performance of individual spotted sea bass.Additionally,white muscle tissues from fish exhibiting good swimming performance(relative U_(crit)>8.20 BL/s)and poor swimming performance(relative U_(crit)<7.31 BL/s)were sampled for RNA-seq.A total of 694 differential expression genes(DEGs)were identified through gene expression analysis,with significant enrichment in GO terms such as mitochondrial protein complex,ribosomal subunit,structural constituent of ribosome,and oxidative phosphorylation,as well as genes in KEGG pathways including ribosome and metabolic pathways.In conclusion,our study for the first time comprehensively elucidated the impact of morphology of spotted sea bass on its individual differences in swimming ability,and analyzed the genetic basis underlying swimming ability using transcriptomic methods.This study provides a theoretical basis for the potential breeding varieties of spotted sea bass suitable for deep-sea aquaculture.
基金joined PI of Westlake University(Grant Nos.041030150118 and 103110556022101)Scientific Research Funding Project of Westlake University(Grant No.2021WUFP017).
文摘The role of hydrodynamic effect in the meeting of multiple fish is a fascinating topic.The interactions of two self-propelled flexi-ble plates swimming in opposite directions horizontally and maintaining a certain lateral distance are numerically simulated using a penalty-immersed boundary method.The effects of the flapping phase and lateral distance on the propulsive performance of two fish meetings are analyzed.Results show that,when two plates meet,if their leading edges diverge laterally,the individual plate can efficiently and rapidly move apart from the other horizontally.If their leading edges converge laterally,the plate motion can be retarded,leading to high energy consumption.Moreover,an increasing lateral distance between two plates significantly weakens the fluid-structure interactions,resulting in an exponential decline in mean cruising speed.A quantitative force analysis based on vortex dynamic theory is performed to gain physics insight into the hydrodynamic interaction mechanism.It is found that lateral separation between the two leading edges enhances the vorticity generation and boundary vorticity flux on the surface of the plate,subsequently reinforcing the thrust effect and increasing horizontal velocity.This study offers insight into the hydro-dynamic mechanisms of the fluid-structure interactions among fish moving toward each other and suggests potential strategies for enhancing the maneuverability of robotic fish in complex environment.
基金supported by the National Natural Science Foundation of China(10172095 and 10672183)
文摘Numerical simulation and control of self- propelled swimming of two- and three-dimensional biomimetic fish school in a viscous flow are investigated. With a parallel computational fluid dynamics package for the two- and three-dimensional moving boundary problem, which combines the adaptive multi-grid finite volume method and the methods of immersed boundary and volume of fluid, it is found that due to the interactions of vortices in the wakes, without proper control, a fish school swim with a given flap- ping rule can not keep the fixed shape of a queue. In order to understand the secret of fish swimming, a new feedback con- trol strategy of fish motion is proposed for the first time, i,e., the locomotion speed is adjusted by the flapping frequency of the caudal, and the direction of swimming is controlled by the swinging of the head of a fish. Results show that with this feedback control strategy, a fish school can keep the good order of a queue in cruising, turning or swimming around circles. This new control strategy, which separates the speed control and direction control, is important in the construction of biomimetic robot fish, with which it greatly simplifies the control devices of a biomimetic robot fish.
文摘Fish have a remarkable amount of variation in their swimming performance, from within species dif- ferences to diversity among major taxonomic groups. Fish swimming is a complex, integrative phenotype and has the ability to plastically respond to a myriad of environmental changes. The plasticity of fish swimming has been observed on whole-organismal traits such as burst speed or critical swimming speed, as well as underlying phenotypes such as muscle fiber types, kinematics, cardiovascular system, and neuronal processes. Whether the plastic responses of fish swimming are beneficial seems to depend on the environmental variable that is changing. For example, because of the effects of temperature on biochemical processes, alterations of fish swimming in response to tem- perature do not seem to be beneficial. In contrast, changes in fish swimming in response to variation in flow may benefit the fish to maintain position in the water column. In this paper, we examine how this plasticity in fish swimming might evolve, focusing on environmental variables that have received the most attention： temperature, habitat, dissolved oxygen, and carbon dioxide variation. Using examples from previous research, we highlight many of the ways fish swimming can plastic- ally respond to environmental variation and discuss potential avenues of future research aimed at understanding how plasticity of fish swimming might evolve. We consider the direct and indirect ef- fects of environmental variation on swimming performance, including changes in swimming kine- matics and suborganismal traits thought to predict swimming performance. We also discuss the role of the evolution of plasticity in shaping macroevolutionary patterns of diversity in fish swimming.
基金Project supported by the National Natural Science Foundation of China(Nos.12132015 and 12372251)the Fundamental Research Funds for the Provincial Universities of Zhejiang of China(No.2023YW69)。
文摘The three-dimensional lattice Boltzmann method(LBM)is used to simulate the motion of a spherical squirmer in a square tube,and the steady motion velocity of a squirmer with different Reynolds numbers(Re,ranging from 0.1 to 2)and swimming types is investigated and analyzed to better understand the swimming characteristics of microorganisms in different environments.First,as the Reynolds number increases,the effect of the inertial forces becomes significant,disrupting the squirmer's ability to maintain its theoretical velocity.Specifically,as the Reynolds number increases,the structure of the flow field around the squirmer changes,affecting its velocity of motion.Notably,the swimming velocity of the squirmer exhibits a quadratic relationship with the type of swimming and the Reynolds number.Second,the narrow tube exerts a significant inhibitory effect on the squirmer motion.In addition,although chirality does not directly affect the swimming velocity of the squirmer,it can indirectly affect the velocity by changing its motion mode.
文摘Hydrodynamic force is an important factor that affects the performance of underwater vehicle.Adapting to the current underwater environment by changing its shape is an important feature of underwater snake-like robots(USLR).An experiment was implemented to verify the swimming along the straight line of USLR.A simulation platform is also established for the analysis of the swimming of USLR.To figure out adaptive swimming of USLR to different underwater environments,the relationships between CPG parameters and maximum swimming speed have been discussed,and the switching between different swimming modes has been implemented.
文摘We investigated the concentration of trihalomethanes （THMs） in tap water and swimming pool water in the area of the Nakhon Path- om Municipality during the period April 2005-March 2006. The concentrations of total THMs, chloroform, bromodichloromethane, dibromochloromethane and bromoform in tap water were 12.70-41.74, 6.72-29.19, 1.12-11.75, 0.63-3.55 and 0.08-3.40 μg/L, respectively, whereas those in swimming pool water were 26.15-65.09, 9.50-36.97, 8.90-18.01, 5.19-22.78 and ND-6.56 μg/L, respectively. It implied that the concentration of THMs in swimming pool water was higher than those in tap water, particularly, brominated-THMs. Both tap water and swimming pool water contained concentrations of total THMs below the standards of the World Health Organization （WHO）, European Union （EU） and the United States Environmental Protection Agency （USEPA） phase Ⅰ, but 1 out of 60 tap water samples and 60 out of 72 swimming pool water samples contained those over the Standard of the USEPA phase Ⅱ. From the two cases of cancer risk assessment including Case Ⅰ Non-Swimmer and Case Ⅱ Swimmer, assessment of cancer risk of nonswimmers from exposure to THMs at the highest and the average concentrations was 4.43×10^-5 and 2.19×10^-5, respectively, which can be classified as acceptable risk according to the Standard of USEPA. Assessment of cancer risk of swimmers from exposure to THMs at the highest and the average concentrations was 1.47×10^-3 and 7.99×10^-4, respectively, which can be classified as unacceptable risk and needs to be improved. Risk of THMs exposure from swimming was 93.9%-94.2% of the total risk. Cancer risk of THMs concluded from various routes in descending order was： skin exposure while swimming, gastro-intestinal exposure from tap water intake, and skin exposure to tap water and gastro-intestinal exposure while swimming. Cancer risk from skin exposure while swimming was 94.18% of the total cancer risk.
基金the National Natural Science Foundation of China (Grant No. 50579007)
文摘There are many kinds of swimming mode in the fish world, and we investigated two of them, used by cyprinids and bulltrout. In this paper we track the locomotion locus by marks in different flow velocity from 0.2 m·s^-1 to 0.8 m·s^-1. By fit the data above we could find out the locomotion mechanism of the two kinds of fish and generate a mathematical model of fish kine- matics. The cyprinid fish has a greater oscillation period and amplitude compared with the bulltrout, and the bulltrout changes velocity mainly by controlling frequency of oscillation.
基金supported by the Natural Science Foundation of China (No. 41276140)
文摘Polybrominated diphenyl ethers（PBDEs） are new kinds of persistent organic pollutants（POPs） and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE（BDE-47）and deca-BDE（BDE-209） were applied, and their toxic effects on the swimming behavior,population growth and reproduction of Brachionus plicatilis were investigated. The results showed that：（1） The actual concentrations of BDE-47 and-209 in the seawater phase measured by GC–MS（Gas Chromatography-Mass Spectrometer） were much lower than their nominal concentrations.（2） In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209.（3） Both BDE-47 and-209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females（OF/NOF）, the ratio of mictic females/amictic females（MF/AF）, resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and-209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.
基金supported by the Natural Science Foundation Project of Chongqing (No. CSTC2011jjA20006)the Research Project of Chongqing Education Committee (No. KJ110606)the projects of Chongqing Normal University (No. 2011XLZ11, 10XLB037)
文摘The potential risks of perfluorooctane sulfonate （PFOS） are of increasing ecological concern. Swimming performance is linked to the fitness and health of fish. However, the impacts of PFOS on swimming performance remain largely unknown. We investigated the ecotoxicological effects of acute exposure to PFOS on the swimming performance and energy expenditure of juvenile goldfish （Carassius auratus）. The fish were exposed to a range of PFOS concentrations （0, 0.5, 2, 8 and 32 mg/L） for 48 hr. The spontaneous swimming activity, fast-start swimming performance, critical swimming speed （Ucrit） and active metabolic rate （AMR） of the goldfish were examined after exposure to PFOS. PFOS exposure resulted in remarkable effects on spontaneous activity. Motion distance was reduced, and the proportion of motionless time increased with increasing concentrations of PFOS. However, no significant alterations in the fast-start performance-related kinematic parameters, such as latency time, maximum linear velocity, maximum linear acceleration or escape distance during the first 120 msec after stimulus, were observed after PFOS exposure. Unexpectedly, although PFOS exposure had marked influences on the swimming oxygen consumption rates and AMR of goldfish, the U crit of the goldfish was not significantly affected by PFOS. This may result in a noteworthy increase in the energetic cost of transport. The overall results indicate that, in contrast to spontaneous activity, underlying swimming capabilities are maintained in goldfish after short-term exposure to PFOS, but energy expenditure during the process of swimming is dramatically aggravated.
基金the Spanish Ministry of Science,Innovation and Universities(projects CGL2013-43822-R and CGL2016-80820-R,AEI/FEDER/EU)and the Government of Catalonia(ref.2017 SGR 548).F.R.-G.was benefitted from a predoctoral fellowship from the University of Girona(IFUdG17).
文摘Energy metabolism fuels swimming and other biological processes.We compared the swimming performance and energy metabolism within and across eight freshwater fish species.Using swim tunnel respirometers,we measured the standard metabolic rate(SMR)and maximum metabolic rate(MMR)and calculated the critical swimming speed(Ucrit).We accounted for body size,metabolic traits,and some morphometric ratios in an effort to understand the extent and underlying causes of variation.Body mass was largely the best predictor of swimming capacity and metabolic traits within species.Moreover,we found that predictive models using total length or SMR,in addition to body mass,signicantly in creased the explained variation of Ucrit and MMR in certain fish species.These predictive models also underlined that,once body mass has been accounted for,Ucrit can be independently affected by total length or MMR.This study exemplifies the utility of multiple regression models to assess within-species variability.At interspecific level,our results showed that variation in UcriX can partly be explained by the variation in the interrelated traits of MMR,finen ess,and muscle ratios.Among the species studied,bleak Al burn us alburnus performed best in terms of swimming performance and efficiency.By contrast,pumpkinseed Lepomis gibbosus showed very poor swimming performance,but attained lower mass-specific cost of transport(MCOT)than some rheophilic species,possibly reflecting a cost reduction strategy to compensate for hydrod yn amic disadvantages.In con elusion,this study provides insight into the key factors in fluenci ng the swimming performa nee of fish at both intra-and in terspecific levels.
基金Supported by the Youth Top Talent Project of Fujian Province,China“Young Eagle Project”(No.2901-750102003)。
文摘Background:Vascular cognitive impairment caused by chronic cerebral hypoperfusion(CCH)has become a hot issue worldwide.Aerobic exercise positively contributes to the preservation or restoration of cognitive abilities;however,the specific mechanism has remained inconclusive.And recent studies found that neurogranin(Ng)is a potential biomarker for cognitive impairment.This study aims to investigate the underlying role of Ng in swimming training to improve cognitive impairment.Methods:To test this hypothesis,the clustered regularly interspaced short palindromic repeats(CRISPR)-associated protein 9(Cas9)system was utilized to construct a strain of Ng conditional knockout(Ng cKO)mice,and bilateral common carotid artery stenosis(BCAS)surgery was performed to prepare the model.In Experiment 1,2-month-old male and female transgenic mice were divided into a control group(wild-type littermate,n=9)and a Ng cKO group(n=9).Then,2-month-old male and female C57BL/6 mice were divided into a sham group(C57BL/6,n=12)and a BCAS group(n=12).In Experiment 2,2-month-old male and female mice were divided into a sham group(wild-type littermate,n=12),BCAS group(n=12),swim group(n=12),BCAS+Ng cKO group(n=12),and swim+Ng cKO group(n=12).Then,7 days after BCAS,mice were given swimming training for 5 weeks(1 week for adaptation and 4 weeks for training,5 days a week,60 min a day).After intervention,laser speckle was used to detect cerebral blood perfusion in the mice,and the T maze and Morris water maze were adopted to test their spatial memory.Furthermore,electrophysiology and Western blotting were conducted to record long-term potential and observe the expressions of Ca^(2+)pathway-related proteins,respectively.Immunohistochemistry was applied to analyze the expression of relevant markers in neuronal damage,inflammation,and white matter injury.Results:The figures showed that spatial memory impairment was detected in Ng cKO mice,and a sharp decline of cerebral blood flow and an impairment of progressive spatial memory were observed in BCAS mice.Regular swimming training improved the spatial memory impairment of BCAS mice.This was achieved by preventing long-term potential damage and reversing the decline of Ca^(2+)signal transduction pathway-related proteins.At the same time,the results suggested that swimming also led to improvements in neuronal death,inflammation,and white matter injury induced by CCH.Further study adopted the use of Ng cKO transgenic mice,and the results indicated that the positive effects of swimming training on cognitive impairments,synaptic plasticity,and related pathological changes caused by CCH could be abolished by the knockout of Ng.Conclusion:Swimming training can mediate the expression of Ng to enhance hippocampal synaptic plasticity and improve related pathological changes induced by CCH,thereby ameliorating the spatial memory impairment of vascular cognitive impairment.
基金the Conseil Régional de Bretagne for financial support
文摘Disinfection by-products(DBPs)are formed in swimming pools by the reactions of bather inputs with the disinfectant.Although a wide range of molecules has been identified within DBPs,only few kinetic rates have been reported.This study investigates the kinetics of chlorine consumption,chloroform formation and dichloroacetonitrile formation caused by human releases.Since the flux and main components of human inputs have been determined and formalized through Body Fluid Analogs(BFAs),it is possible to model the DBPs formation kinetics by studying a limited number of precursor molecules.For each parameter the individual contributions of BFA components have been quantified and kinetic rates have been determined,based on reaction mechanisms proposed in the literature.With a molar consumption of 4 mol Cl2/mol,urea is confirmed as the major chlorine consumer in the BFA because of its high concentration in human releases.The higher reactivity of ammonia is however highlighted.Citric acid is responsible for most of the chloroform produced during BFA chlorination.Chloroform formation is relatively slow with a limiting rate constant determined at 5.50×10^-3 L/mol/sec.L-histidine is the only precursor for dichloroacetonitrile in the BFA.This DBP is rapidly formed and its degradation by hydrolysis and by reaction with hypochlorite shortens its lifetime in the basin.Reaction rates of dichloroacetonitrile formation by L-histidine chlorination have been established based on the latest chlorination mechanisms proposed.Moreover,this study shows that the reactivity toward chlorine differs whether L-histidine is isolated or mixed with BFA components.
基金This work was supported by the National Research Foundation of Korea(NRF)Grant funded by the Korea government(MSIT)(NRF-2022R1A2C2004771)Internal Research Grant by ORIC,SukkurIBA University 2022.
文摘Inspired by the simple yet amazing morphology of the Octopus, we propose the design, fabrication, and characterization of multi-material bio-inspired soft Octopus robot (Octobot). 3D printed molds for tentacles and head were used. The tentacles of the Octobot were casted using Ecoflex-0030 while head was fabricated using relatively flexible material, i.e., OOMOO-25. The head is attached to the functionally responsive tentacles (each tentacle is of 79.12 mm length and 7 void space diameter), whereas Shape Memory Alloy (SMA) muscle wires of 0.5 mm thickness are used in Octobot tentacles for dual thrust generation and actuation of Octobot. The tentacles were separated in two groups and were synchronously actuated. Each tentacle of the developed Octobot contains a pair of SMA muscles (SMA-α and SMA-β). SMA-α muscles being the main actuator, was powered by 9 V, 350 mA power supply, whereas SMA-β was used to provide back thrust and thus helps to increase the actuation frequency. Simulation work of the proposed model was performed in the SolidWorks environment to verify the vertical velocity using the octopus tentacle actuation. The design morphology of Octobot was optimized using simulation and TRACKER software by analyzing the experimental data of angle, displacement, and velocity of real octopus. The as-developed Octobot can swim at variable frequencies (0.5–2 Hz) with the average speed of 25 mm/s (0.5 BLS). Therefore, the proposed soft Octopus robot showed an excellent capability of mimicking the gait pattern of its natural counterpart.
基金Supported by the Agriculture Science Technology Achievement Transformation Fund(No.2014GB2C22015)the Public Projects of Zhejiang Province(Nos.2013C32037,2013C31032)+3 种基金the Zhejiang Major Special Program of Breeding(No.2012C12907-3)the Ningbo Innovation and Entrepreneurship Project(No.2014C92011)the Zhejiang Provincial Oceanic and Fishery Bureau ProjectZhoushan Science and Technology Bureau Project(No.2013C41007)
文摘This study was conducted to evaluate the effects of dietary lipid sources on the growth performance and fatty acid composition of the swimming crab, P ortunus trituberculatus. Four isonitrogenous and isoenergetic experimental diets were formulated to contain four separate lipid sources, including fish, soybean, rapeseed, and linseed oils(FO, SO, RO, and LO, respectively). With three replicates of 18 crabs each for each diet, crabs(initial body weight, 17.00 ±0.09 g) were fed twice daily for 8 weeks. There were no significant differences among these groups in terms of weight gain, specific growth rate, and hepatosomatic index. However, the RO groups' survival rate was significantly lower than FO groups. The feed conversion and protein efficiency ratios of RO groups were poorer than other groups. The proximate compositions of whole body and hepatopancreas were significantly affected by these dietary treatments. Tissue fatty acid composition mainly reflected dietary fatty acid compositions. Crabs fed FO diets exhibited significantly higher arachidonic, eicosapentaenoic, and docosahexaenoic acid contents in muscle and hepatopancreas compared with VO crabs. Linoleic, oleic, and linolenic acids in muscle and hepatopancreas were the highest in the SO, RO, and LO groups, respectively. The present study suggested that SO and LO could substitute for FO in fishmeal-based diets for swimming crabs, without affecting growth performance and survival.
