In recent years,scholars around the world have shown increasing interest in elastic support structures,leading to significant progress in dynamic modeling techniques for pipeline systems.Although multiple analytical a...In recent years,scholars around the world have shown increasing interest in elastic support structures,leading to significant progress in dynamic modeling techniques for pipeline systems.Although multiple analytical approaches exist,engineers increasingly prioritize computationally efficient,precise low-order models for practical implementation.In order to address this need,this study develops an innovative nonlinear dynamic formulation for pipelines accounting for both foundation and boundary nonlinearities.The proposed solution methodology initiates with global mode extraction using the global mode technique,followed by a detailed implementation procedure.Model validation is conducted through a cantilever pipeline case study featuring nonlinear support conditions,where strong agreement between the proposed model's predictions and finiteelement benchmark solutions demonstrates its reliability.Subsequently,a comprehensive parametric study investigates the combined effects of foundation stiffness,boundary constraints,excitation intensity,and nonlinear interaction terms on the vibrational response of the cantilever pipe.This systematic approach yields critical insights for practical engineering designs and applications.展开更多
Background With the global expansion of aquaculture and the increasing demand for fish meal,identifying appropriate and sustainable alternative protein sources for aquafeeds has become essential.Single-cell protein(SC...Background With the global expansion of aquaculture and the increasing demand for fish meal,identifying appropriate and sustainable alternative protein sources for aquafeeds has become essential.Single-cell protein(SCP),derived from methanotrophic bacteria,presents a promising alternative by converting methane into protein,potentially addressing both the need for alternative protein sources and reducing industrial greenhouse gas emissions.This study aimed to evaluate the effects of different levels of SCP inclusion(0%,25%,50%,and 75%fish meal replacement)on the health,gene expression,and gut microbiome of yellowtail kingfish(YTK,Seriola lalandi)following a 35-day growth trial.Results The study found that SCP inclusion at the highest level of fishmeal replacement(75%)induced a mild inflammatory response in the hindgut of the fish.However,micromorphological assessments of the hindgut,serum biochemistry,and gene expression analyses revealed no significant detrimental effects from SCP replacement.Notably,there were indications of improved lipid digestibility with SCP.Furthermore,SCP inclusion significantly enhanced microbial richness and altered the composition of the gut microbiome,introducing beneficial bacterial taxa that may contribute to improved gut health and resilience.Conclusions This study highlights SCP as a viable and sustainable alternative to fish meal in YTK diets.The findings suggest that SCP can be included in YTK diets without adverse health effects at moderate levels and may even offer benefits in terms of lipid digestibility and gut microbiome diversity.These results contribute to the advancement of more sustainable aquaculture practices.展开更多
Penaeus vannamei, known as the whiteleg shrimp, holds significant economic importance in aquaculture. The intensive culture of P. vannamei poses substantial environmental risks, particularly in fragile ecosystems like...Penaeus vannamei, known as the whiteleg shrimp, holds significant economic importance in aquaculture. The intensive culture of P. vannamei poses substantial environmental risks, particularly in fragile ecosystems like estuarine mangroves. Although there is a consensus on the pollution and harmful effects of microplastics(MPs), study on the pollution and potential risks posed by P. vannamei in estuary mangroves remains scarce. Therefore, the extent of microplastic pollution was evaluated and the correlation between the properties of MPs and the potential risks they pose to P. vannamei was examined.The average MP abundance in P. vannamei from Jiulong River estuary was determined to be 0.46±0.03 n/g in five different polymers, i.e., polypropylene(PP), polyethylene(PE), polystyrene(PS), polyethylene terephthalate(PET), and polyvinyl chloride resin(PVC). The total percentage of PS, PE, and PET polymers was the greatest(73.85%), where PET and PP(26.16%) were highly correlated in size and shape. Small MPs(1-200 μm) come in irregular particles, fragments, films, and large-sized MPs(200-1 000 μm) were mainly foam-shaped. The hazard risk level of MPs in P. vannamei from Jiulong River estuary reached grade Ⅲ, and the overall hazard risk index(H) value was 593.66. Among all samples,PVC polymer accounted for the lowest proportion(5.52%), but the H value was as high as 582.42, which contributed 98.11% to the overall hazard risk index. Regardless of global or Chinese, the microplastic pollution of P. vannamei in the estuary is at a moderate level. The protocol for MPs characteristics and correlation in seafood should be the basis for the risk assessment framework. Further studies are needed to evaluate how the exposure to MPs poses a risk for human health.展开更多
Laminarin oligosaccharides(LOSs)with a specific degree of polymerization prepared through the laminarin degradation via laminarinase present more significant nutritional functions and application values.Human intestin...Laminarin oligosaccharides(LOSs)with a specific degree of polymerization prepared through the laminarin degradation via laminarinase present more significant nutritional functions and application values.Human intestinal bacteria are promising potential producers of novel carbohydrate-active enzymes with unique properties.Here,a novel glycoside hydrolase family 128(GH128)laminarinase OUC-BsLam26 from the intestinal bacterium Bacteroides sp.CBA7301 was heterologously expressed and characterized.The recombinant OUC-BsLam26 with a molecular mass of 49.86 kDa exhibits highest activity(6.60 U/mg)at 45℃ and pH 6.0,which shows noticeable temperature and pH stability.The purified OUC-BsLam26 could degrade laminarin via an endo-type mode with the generation of laminaripentaose,laminaritetraose,laminaritriose,and laminaribiose,among them,laminaritetraose is the principal product,which accounts for 45.25% of the total products,which is significantly different from the reported GH128 laminarinases.The minimum recognition substrate of OUC-BsLam26 is laminarihexaose.Furthermore,OUC-BsLam26 also could catalyze the transglycosylation process with the production of some novel glycosides.Altogether,the intestinal bacterium Bacteroides sp.CBA7301 contains laminarinase with unique product composition and OUC-BsLam26 is a hopeful bio-catalyst with the potential to produce laminaritetraose and some novel glycosides.展开更多
Recent studies identify large uncertainties in the projections of tropical cyclone(TC)activity due to discrepancies in tropical Pacific sea surface temperature(SST)warming patterns.While observational datasets consist...Recent studies identify large uncertainties in the projections of tropical cyclone(TC)activity due to discrepancies in tropical Pacific sea surface temperature(SST)warming patterns.While observational datasets consistently reveal a La Niña-like warming pattern[0.15℃-0.25℃(10 yr)^(−1) relative cooling in the eastern equatorial Pacific],over 80%of CMIP6 models project an erroneous El Niño-like trend.These discrepancies arise from biases in cloud feedbacks,Walker circulation strength,and oceanic upwelling processes.This review examines the key mechanisms shaping observed versus modeled warming patterns,evaluates the complex link between tropical SST patterns and TC activity,and explores the feasibility of storm-resolving models for improving TC projections.We propose that pattern-conditioned TC projections using convection-permitting models,alongside physics-informed interpretations,offer a path forward in reducing uncertainties in future climate predictions.展开更多
Microplastic(MP)contamination is becoming a major worldwide concern,affecting terrestrial and aquatic ecosystems.This study investigated the source,distribution,and abundance of MPs in sediments from Dongshan Bay,Fuji...Microplastic(MP)contamination is becoming a major worldwide concern,affecting terrestrial and aquatic ecosystems.This study investigated the source,distribution,and abundance of MPs in sediments from Dongshan Bay,Fujian,South China,emphasizing particularly the coastline region's susceptibility to tidal impacts in four study sites.The concentrations of MPs in the sediments in the four sites were high from 7.4 to 283.1 items/kg(dry weight).There were notable differences in abundance between the locations and tide levels.Tides influenced the distribution of MPs greatly;however,the estuary areas showed greater MPs abundance during high tide,due possibly to enhanced water turbulence and riverine inputs.Low tide indicated higher concentrations in coastal locations owing to accumulation.Popular varieties,including nylon,polypropylene,and polyethylene,were identified by polymer research,pointing to the origins from fishing,packaging,and mariculture industries.Potential sources were determined using the PCA-K-means statistical analysis,by linking the origins of MPs to domestic activities,fishing,mariculturing,shipping,and packing.Fishing and packing were shown in the Sankey diagram as the two main sources,but their effects varied with research locations and tidal regimes.This study clarified the intricate dynamics of MPs pollution,highlighting the impact of tides on its dispersal and the variety of sources that contribute to this widespread environmental problem in coastal areas.展开更多
Microplastics(MPs)have recently emerged as a significant environmental problem with devastating consequences for organisms.Understanding MPs pollution in the Bay of Bengal is crucial for assessing its ecological impac...Microplastics(MPs)have recently emerged as a significant environmental problem with devastating consequences for organisms.Understanding MPs pollution in the Bay of Bengal is crucial for assessing its ecological impact on marine biodiversity and human health.This study examined the occurrence,spatial distribution,physical and chemical properties,ecological risks,and probable sources of MPs in estuarine and coastal marine environments in the northeastern Bay of Bengal.The average concentration of MPs in surface water of the Karnaphuli estuary,the Meghna estuary,and the southeastern coastal region were 916.7±462.6 items/m^(3),462.9±324.5 items/m^(3),and 350.0±190.5 items/m^(3),respectively,varying from 105.0±324.5 items/m^(3)to 1640.0±462.6 items/m^(3).In the sediments of the Karnaphuli estuary,the Meghna estuary,and the southeast coast of Bangladesh,the average amount of MPs were 94.3±33.1 items/kg,157.6±89.0 items/kg,and 134.3±38.7 items/kg,with a range of 60±33.1 items/kg to 334.3±89.0 items/kg.Most observed MPs were fibers(60.0%in the water;56.0%in the sediments),followed by fragments and lines.Detected MPs were dominated by polypropylene(20.7%)in the water,and acrylic(15.4%)in the sediment,black colored(76.2%in the water,72.7%in the sediments),and 200-500μm sized(48%in the water,37%in the sediments).Pollution Risk Index(PRI)indicated significant pollution levels(from medium to very high)in estuarine and coastal areas.Multi-statistical analysis indicated land-based inputs(tourists,local waste,agriculture,and industry)dominated the studied regions.The study emphasized the potential impact of MPs pollution on aquatic ecosystems,emphasizing the need for effective management,mitigation methods,continuous surveillance,and thorough evaluation.展开更多
This study aims, first, to examine the limit for tolerance to lower salinity by an oceanic sea skater, Halobates micans, and , second, to make it clear whether exclusively fresh water Halobatinae species, Metrocoris h...This study aims, first, to examine the limit for tolerance to lower salinity by an oceanic sea skater, Halobates micans, and , second, to make it clear whether exclusively fresh water Halobatinae species, Metrocoris histrio has salinity tolerance. Adults of H. micans were collected using Neuston Net from the starboard side of R/V MIRAI on a fixed station at 8°S, 80°E, whereas those of M. histrio were collected from a small pond filled with a spring fresh water in Kochi (33°N, 133°E), Japan. Time in survival was measured in starved condition under several salinity conditions: 0‰, 2‰, 4‰, 6‰, 8‰, 9‰ and 10‰ for H. micans;0‰, 5‰, 10‰, 12.5‰, 15‰ for M. histrio. Half of adults were in coma due to lower salinity under 10‰ and time in survival was less than 10 hours under less than 4‰ for H. micans. Time in survival was half at 5‰ of 80 hours on average at 0‰ as a control and less than 10 hours at 10‰ or higher salinity for M. histrio. Relatively flexible osmo-regulation ability by H. micans would be related to wide variety of salinity condition of surface oceanic water, whereas very limited tolerance even to lower salinity of 5‰ may be permitted by the no chances to be exposed to brackish water in natural habitats of M. histrio. This study showed that salinity tolerance of Halobatinae species would reflect, directly, the salinity condition of their habitats.展开更多
To address various fisheries science problems around Japan, the Japan Fisheries Research and Education Agency (FRA) has developed an ocean forecast system by combining an ocean circulation model based on the Regional ...To address various fisheries science problems around Japan, the Japan Fisheries Research and Education Agency (FRA) has developed an ocean forecast system by combining an ocean circulation model based on the Regional Ocean Modeling System (ROMS) with three-dimensional variational analysis schemes. This system, which is called FRA-ROMS, is a basic and essential tool for the systematic conduct of fisheries science. The main aim of FRA-ROMS is to realistically simulate mesoscale variations over the Kuroshio-Oyashio region. Here, in situ oceanographic and satellite data were assimilated into FRA-ROMS using a weekly time window. We first examined the reproducibility through comparison with several oceanographic datasets with an Eulerian reference frame. FRA-ROMS was able to reproduce representative features of mesoscale variations such as the position of the Kuroshio path, variability of the Kuroshio Extension, and southward intrusions of the Oyashio. Second, using a Lagrangian reference frame, we estimated position errors between ocean drifters and particles passively transported by simulated currents, because particle tracking is an essential technique used in applications of reanalysis products to fisheries science. Finally, we summarize recent and ongoing fisheries studies that use FRA-ROMS and mention several new developments and enhancements that will be implemented in the near future.展开更多
The PIRATA-SWE （Prediction and Research Moored Array in the Tropical Atlantic-Southwest Extension） was conceived in the early 2000s to gather observations necessary to improve the understanding of the variability of...The PIRATA-SWE （Prediction and Research Moored Array in the Tropical Atlantic-Southwest Extension） was conceived in the early 2000s to gather observations necessary to improve the understanding of the variability of ocean-atmosphere interactions in the SACZ （South Atlantic Convergence Zone）, which are believed to influence South American climate. To properly monitor the SACZ, the preliminary design for the PIRATA-SWE array considered the mooring of four buoys, with the southernmost one in the sub-tropics. In 2005, three buoys were deployed in the tropical region. Four years later, in 2009, efforts were started to assemble and deploy a Brazilian prototype of the TAO/PIRATA Atlas （autonomous temperature line acquisition system） buoy-the Atlas-B. Finally, in April 2013 the first Atlas-B, nicknamed ＂Guariroba＂, was moored for a testing period at 28.5° S, 44° W, which is the site originally planned for the fourth PIRATA-SWE buoy. In early November 2013, after being detected adrift, the buoy with the upper 700 m part of the mooring line was rescued in an emergency operation. In June 2014, the bottom part was successfully recovered. A new deployment is planned for late 2014. This paper describes part of the learning process of adapting and building the Atlas-B buoy and presents a brief discussion of the data collected during the pilot deployment.展开更多
The main purpose of this study is to investigate temperature preference for habitat of three species of oceanic sea skaters, Halobates micans, H. germanus and H. sericeus. For each of the three species, we examined th...The main purpose of this study is to investigate temperature preference for habitat of three species of oceanic sea skaters, Halobates micans, H. germanus and H. sericeus. For each of the three species, we examined the relationship between population density and surface water and air temperatures in the sampling sites during three science cruises in the tropical to temperate zone of the Pacific Ocean. A higher density of H. micans was observed in sites with higher water and air temperatures at 28℃?- 30℃?than that at site with lower temperatures of 23℃?- 28℃. A higher density of H. germanus was observed in sites with extremely high temperatures of 29.6℃?and 30℃?than that in sites with moderately high temperatures of 28℃?- 29℃?in the Pacific Ocean, while a relatively high density was observed in sites with a wide range of temperatures from 24℃?- 30℃?in the southern hemisphere Pacific Ocean. The relatively low temperature preference of 23℃?- 28℃?exhibited by H. sericeus may be related to its size as the smallest among the three species and its relatively wide latitudinal distribution ranging up to 40?N.展开更多
Tool wear is a critical challenge in titanium alloy friction stir welding(FSW).Vortex flow-based FSW(VFSW)is a potential solution for this issue because the VFSW process uses a similar material to the base metal as th...Tool wear is a critical challenge in titanium alloy friction stir welding(FSW).Vortex flow-based FSW(VFSW)is a potential solution for this issue because the VFSW process uses a similar material to the base metal as the tool.In this study,TC4 titanium alloy was welded by VFSW for the first time.Parameter optimization of the vortex flow formation is first done,and then the weld formation and the joints'microstructure and mechanical performance are investigated at different traversing speeds.The results prove that the plunging velocity is the dominant factor in the vortex depth.A lower plunging speed is beneficial for the formation of a deeper vortex.Full penetration is achieved at traversing speeds of 50–120 mm/min at 300 r/min.At welding speed above 130 mm/min,insufficient penetration defects occur.In the heat affected zone,grain coarsening andβ-phase volume fraction increase arise,whereas,in the weld nugget,anα+βlamellar structure emerges.Under the optimized parameters,the joint tensile strength is nearly 98%of the base material,but the elongation decreases significantly.The oxides drawn into the weld by the vortex at the junction between the vortex and the base material are the main reason for the small elongation.This study proves that the VFSW process is feasible for titanium alloys.展开更多
Stable water isotopes are natural tracers quantifying the contribution of moisture recycling to local precipitation,i.e.,the moisture recycling ratio,but various isotope-based models usually lead to different results,...Stable water isotopes are natural tracers quantifying the contribution of moisture recycling to local precipitation,i.e.,the moisture recycling ratio,but various isotope-based models usually lead to different results,which affects the accuracy of local moisture recycling.In this study,a total of 18 stations from four typical areas in China were selected to compare the performance of isotope-based linear and Bayesian mixing models and to determine local moisture recycling ratio.Among the three vapor sources including advection,transpiration,and surface evaporation,the advection vapor usually played a dominant role,and the contribution of surface evaporation was less than that of transpiration.When the abnormal values were ignored,the arithmetic averages of differences between isotope-based linear and the Bayesian mixing models were 0.9%for transpiration,0.2%for surface evaporation,and–1.1%for advection,respectively,and the medians were 0.5%,0.2%,and–0.8%,respectively.The importance of transpiration was slightly less for most cases when the Bayesian mixing model was applied,and the contribution of advection was relatively larger.The Bayesian mixing model was found to perform better in determining an efficient solution since linear model sometimes resulted in negative contribution ratios.Sensitivity test with two isotope scenarios indicated that the Bayesian model had a relatively low sensitivity to the changes in isotope input,and it was important to accurately estimate the isotopes in precipitation vapor.Generally,the Bayesian mixing model should be recommended instead of a linear model.The findings are useful for understanding the performance of isotope-based linear and Bayesian mixing models under various climate backgrounds.展开更多
Water-related hazards, such as river floods, flash floods and droughts, are becoming more frequent in the Upper Chao Phraya River Basin, Thailand, due to climate change and urbanization, causing significant societal, ...Water-related hazards, such as river floods, flash floods and droughts, are becoming more frequent in the Upper Chao Phraya River Basin, Thailand, due to climate change and urbanization, causing significant societal, economic, and environmental damage. This study supports decision-making for nature-based solutions (NBS) to address mitigate these hazards. Using multi-criteria decision analysis, simulation modeling, and spatial analysis, the study identified precipitation and river discharges as key hazard drivers. Mapping hazard severity at various scales, the findings suggest that expanding green areas and water storage can enhance water management and reduce hazard impacts. This research offers critical insights for NBS adoption in water-related risk reduction.展开更多
Rice blast disease, caused by Magnaporthe oryzae, threatens global food security. The rice blast pathosystem is a longstanding model system for understanding plant-microbe interactions. In order to elucidate the coevo...Rice blast disease, caused by Magnaporthe oryzae, threatens global food security. The rice blast pathosystem is a longstanding model system for understanding plant-microbe interactions. In order to elucidate the coevolution of the host and pathogen, and provide the appropriate methods for preventing or controlling rice blast disease, researchers have focused on the evolution of virulence factors and resistance genes. Thus far, more than 30 rice blast resistance（R） genes and 12 avirulence（Avr） genes have been cloned. This review summarizes the cloned rice blast R genes, cloned Avr genes of M. oryzae and the interaction between them. This discussion also considers some of the major unanswered questions concerning this pathosystem and the opportunities for future investigations.展开更多
Based on the test data in dynamic water and static water, the main factors, which influence the fine sediment flocculation, are analyzed with a gray model method of correlation theory. It is shown that the main influe...Based on the test data in dynamic water and static water, the main factors, which influence the fine sediment flocculation, are analyzed with a gray model method of correlation theory. It is shown that the main influencing factors are water temperature, settling time, salinity, grain size, sediment concentration and current velocity according to the correlation coefficients. Among them, the salinity and the sediment grain size are critical type influencing factors (CrTIF); the settling time, the sediment concentration and the velocity are continuous type influencing factors (CoTIF); and the water temperature has the characteristics of both. When the critical values of CrTIF are reached or exceeded, the fine sediments will be flocculated, but values of CrTIF will not influence the settlement strength of floes. The influence of CoTIF is continuous. The values of the CoTIF will not only influence the occurrence of flocculation but also the settlement strength of the floes.展开更多
Highly fecund marine species with dispersive life-history stages often display large population sizes and wide geographic distribution ranges. Consequently, they are expected to experience reduced genetic drift, effic...Highly fecund marine species with dispersive life-history stages often display large population sizes and wide geographic distribution ranges. Consequently, they are expected to experience reduced genetic drift, efficient selection fueled by frequent adaptive mutations, and high migration loads. This has important consequences for understanding how local adaptation proceeds in the sea. A key issue in this regard, relates to the genetic architecture underlying fitness traits. Theory predicts that adaptation may involve many genes but with a high variance in effect size. Therefore, the effect of selection on allele frequencies may be substantial for the largest effect size loci, but insignificant for small effect genes. In such a context, the performance of population genomic methods to unravel the genetic basis of adaptation depends on the fraction of adaptive genetic variance explained by the cumulative effect of outlier loci. Here, we address some methodological challenges associated with the detection of local adaptation using molecular approaches. We provide an overview of genome scan methods to detect selection, including those assuming complex demographic models that better describe spatial population structure. We then focus on quantitative genetics approaches that search for genotype-phenotype associations at different genomic scales, including genome-wide methods evaluating the cumulative effect of variants. We argue that the limited power of single locus tests can be alleviated by the use of polygenic scores to estimate the joint contribution of candidate variants to phenotypic variation.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52401342 and 12572025)the Fundamental Research Funds for the Central Universities of China(Nos.D5000240076 and G2025KY05171)+1 种基金the Natural Science Basic Research Program of Shaanxi Province(No.2025JCYBMS-026)the Basic Research Programs of Taicang(No.TC2024JC36)。
文摘In recent years,scholars around the world have shown increasing interest in elastic support structures,leading to significant progress in dynamic modeling techniques for pipeline systems.Although multiple analytical approaches exist,engineers increasingly prioritize computationally efficient,precise low-order models for practical implementation.In order to address this need,this study develops an innovative nonlinear dynamic formulation for pipelines accounting for both foundation and boundary nonlinearities.The proposed solution methodology initiates with global mode extraction using the global mode technique,followed by a detailed implementation procedure.Model validation is conducted through a cantilever pipeline case study featuring nonlinear support conditions,where strong agreement between the proposed model's predictions and finiteelement benchmark solutions demonstrates its reliability.Subsequently,a comprehensive parametric study investigates the combined effects of foundation stiffness,boundary constraints,excitation intensity,and nonlinear interaction terms on the vibrational response of the cantilever pipe.This systematic approach yields critical insights for practical engineering designs and applications.
基金Fisheries Research Development Corporation,Grant/Award Number:2017-030.
文摘Background With the global expansion of aquaculture and the increasing demand for fish meal,identifying appropriate and sustainable alternative protein sources for aquafeeds has become essential.Single-cell protein(SCP),derived from methanotrophic bacteria,presents a promising alternative by converting methane into protein,potentially addressing both the need for alternative protein sources and reducing industrial greenhouse gas emissions.This study aimed to evaluate the effects of different levels of SCP inclusion(0%,25%,50%,and 75%fish meal replacement)on the health,gene expression,and gut microbiome of yellowtail kingfish(YTK,Seriola lalandi)following a 35-day growth trial.Results The study found that SCP inclusion at the highest level of fishmeal replacement(75%)induced a mild inflammatory response in the hindgut of the fish.However,micromorphological assessments of the hindgut,serum biochemistry,and gene expression analyses revealed no significant detrimental effects from SCP replacement.Notably,there were indications of improved lipid digestibility with SCP.Furthermore,SCP inclusion significantly enhanced microbial richness and altered the composition of the gut microbiome,introducing beneficial bacterial taxa that may contribute to improved gut health and resilience.Conclusions This study highlights SCP as a viable and sustainable alternative to fish meal in YTK diets.The findings suggest that SCP can be included in YTK diets without adverse health effects at moderate levels and may even offer benefits in terms of lipid digestibility and gut microbiome diversity.These results contribute to the advancement of more sustainable aquaculture practices.
基金Supported by the Natural Science Foundation of Xiamen (No. 3502Z20227322)the Natural Science Key Foundation of Fujian Province (No. 2020J02002)+1 种基金the Social Science Foundation of Fujian Province (No. FJ2024BF047)the Financial Research Projects of Fujian Province (No. 2024-48)。
文摘Penaeus vannamei, known as the whiteleg shrimp, holds significant economic importance in aquaculture. The intensive culture of P. vannamei poses substantial environmental risks, particularly in fragile ecosystems like estuarine mangroves. Although there is a consensus on the pollution and harmful effects of microplastics(MPs), study on the pollution and potential risks posed by P. vannamei in estuary mangroves remains scarce. Therefore, the extent of microplastic pollution was evaluated and the correlation between the properties of MPs and the potential risks they pose to P. vannamei was examined.The average MP abundance in P. vannamei from Jiulong River estuary was determined to be 0.46±0.03 n/g in five different polymers, i.e., polypropylene(PP), polyethylene(PE), polystyrene(PS), polyethylene terephthalate(PET), and polyvinyl chloride resin(PVC). The total percentage of PS, PE, and PET polymers was the greatest(73.85%), where PET and PP(26.16%) were highly correlated in size and shape. Small MPs(1-200 μm) come in irregular particles, fragments, films, and large-sized MPs(200-1 000 μm) were mainly foam-shaped. The hazard risk level of MPs in P. vannamei from Jiulong River estuary reached grade Ⅲ, and the overall hazard risk index(H) value was 593.66. Among all samples,PVC polymer accounted for the lowest proportion(5.52%), but the H value was as high as 582.42, which contributed 98.11% to the overall hazard risk index. Regardless of global or Chinese, the microplastic pollution of P. vannamei in the estuary is at a moderate level. The protocol for MPs characteristics and correlation in seafood should be the basis for the risk assessment framework. Further studies are needed to evaluate how the exposure to MPs poses a risk for human health.
基金supported by the National Natural Science Foundation of China(32072159)Natural Science Foundation of Hainan Province(322QN338)+4 种基金Young Talent of Lifting Engineering for Science and Technology in Shandong,China(SDAST2021qt18)Qingdao Science and Technology Plan Key Research and Development Project(22-3-3-hygg-28-hy)Fundamental Research Funds for the Central Universities(202262003)Taishan Scholar Project of Shandong Province(tsqn202312099)Support Program for Youth Innovation Technology in Colleges and Universities of Shandong Province(2023KJ041)。
文摘Laminarin oligosaccharides(LOSs)with a specific degree of polymerization prepared through the laminarin degradation via laminarinase present more significant nutritional functions and application values.Human intestinal bacteria are promising potential producers of novel carbohydrate-active enzymes with unique properties.Here,a novel glycoside hydrolase family 128(GH128)laminarinase OUC-BsLam26 from the intestinal bacterium Bacteroides sp.CBA7301 was heterologously expressed and characterized.The recombinant OUC-BsLam26 with a molecular mass of 49.86 kDa exhibits highest activity(6.60 U/mg)at 45℃ and pH 6.0,which shows noticeable temperature and pH stability.The purified OUC-BsLam26 could degrade laminarin via an endo-type mode with the generation of laminaripentaose,laminaritetraose,laminaritriose,and laminaribiose,among them,laminaritetraose is the principal product,which accounts for 45.25% of the total products,which is significantly different from the reported GH128 laminarinases.The minimum recognition substrate of OUC-BsLam26 is laminarihexaose.Furthermore,OUC-BsLam26 also could catalyze the transglycosylation process with the production of some novel glycosides.Altogether,the intestinal bacterium Bacteroides sp.CBA7301 contains laminarinase with unique product composition and OUC-BsLam26 is a hopeful bio-catalyst with the potential to produce laminaritetraose and some novel glycosides.
基金supported partly by the AORI visiting professorship programsupported in part by a Moonshot R&D grant(Grant No.JPMJMS2282-02)from the Japan Science and Technology Agency+1 种基金the JSPS Core-to-Core Program,“International Core-to-Core Project on Global Storm Resolving Analysis”(Grant No.JPJSCCA20220001)JSPS KAKENHI(Grant Nos.20B202,20H05728,and 24K00703)。
文摘Recent studies identify large uncertainties in the projections of tropical cyclone(TC)activity due to discrepancies in tropical Pacific sea surface temperature(SST)warming patterns.While observational datasets consistently reveal a La Niña-like warming pattern[0.15℃-0.25℃(10 yr)^(−1) relative cooling in the eastern equatorial Pacific],over 80%of CMIP6 models project an erroneous El Niño-like trend.These discrepancies arise from biases in cloud feedbacks,Walker circulation strength,and oceanic upwelling processes.This review examines the key mechanisms shaping observed versus modeled warming patterns,evaluates the complex link between tropical SST patterns and TC activity,and explores the feasibility of storm-resolving models for improving TC projections.We propose that pattern-conditioned TC projections using convection-permitting models,alongside physics-informed interpretations,offer a path forward in reducing uncertainties in future climate predictions.
基金the Natural Science Key Foundation of Fujian ProvinceChina(No.2020J02002)+4 种基金the Hainan Province Science and Technology Special Fund(No.ZDYF2022SHFZ317)the National Natural Science Foundation of China(Nos.U2005207,41976216,41776088,42106224)the Norwegian Institute of FoodFishery and AquacultureGovernance of Marine Plastic Litter in the Arctic。
文摘Microplastic(MP)contamination is becoming a major worldwide concern,affecting terrestrial and aquatic ecosystems.This study investigated the source,distribution,and abundance of MPs in sediments from Dongshan Bay,Fujian,South China,emphasizing particularly the coastline region's susceptibility to tidal impacts in four study sites.The concentrations of MPs in the sediments in the four sites were high from 7.4 to 283.1 items/kg(dry weight).There were notable differences in abundance between the locations and tide levels.Tides influenced the distribution of MPs greatly;however,the estuary areas showed greater MPs abundance during high tide,due possibly to enhanced water turbulence and riverine inputs.Low tide indicated higher concentrations in coastal locations owing to accumulation.Popular varieties,including nylon,polypropylene,and polyethylene,were identified by polymer research,pointing to the origins from fishing,packaging,and mariculture industries.Potential sources were determined using the PCA-K-means statistical analysis,by linking the origins of MPs to domestic activities,fishing,mariculturing,shipping,and packing.Fishing and packing were shown in the Sankey diagram as the two main sources,but their effects varied with research locations and tidal regimes.This study clarified the intricate dynamics of MPs pollution,highlighting the impact of tides on its dispersal and the variety of sources that contribute to this widespread environmental problem in coastal areas.
基金Supported by the National Natural Science Foundation of China(NSFC)Shared Voyage Project(Nos.41776088,41976018,42049911,U20A20103,U2005207)the Natural Science Key Foundation of Fujian Province,China(No.2020J01412103)+5 种基金the Hainan Province Science and Technology Special Fund(No.ZDYF2022SHFZ317)the Guangxi Talent and Innovation Base Project(No.2018AD19280)the Guangxi Funding Project(No.04024XM20N0006)the Beihai Science&Technology Project(Nos.201995037,202082031,202082022)the Natural Science Foundation of Xiamen City of China(No.502Z20227322)the China Scholarship Council(CSC Marine Scholarship)。
文摘Microplastics(MPs)have recently emerged as a significant environmental problem with devastating consequences for organisms.Understanding MPs pollution in the Bay of Bengal is crucial for assessing its ecological impact on marine biodiversity and human health.This study examined the occurrence,spatial distribution,physical and chemical properties,ecological risks,and probable sources of MPs in estuarine and coastal marine environments in the northeastern Bay of Bengal.The average concentration of MPs in surface water of the Karnaphuli estuary,the Meghna estuary,and the southeastern coastal region were 916.7±462.6 items/m^(3),462.9±324.5 items/m^(3),and 350.0±190.5 items/m^(3),respectively,varying from 105.0±324.5 items/m^(3)to 1640.0±462.6 items/m^(3).In the sediments of the Karnaphuli estuary,the Meghna estuary,and the southeast coast of Bangladesh,the average amount of MPs were 94.3±33.1 items/kg,157.6±89.0 items/kg,and 134.3±38.7 items/kg,with a range of 60±33.1 items/kg to 334.3±89.0 items/kg.Most observed MPs were fibers(60.0%in the water;56.0%in the sediments),followed by fragments and lines.Detected MPs were dominated by polypropylene(20.7%)in the water,and acrylic(15.4%)in the sediment,black colored(76.2%in the water,72.7%in the sediments),and 200-500μm sized(48%in the water,37%in the sediments).Pollution Risk Index(PRI)indicated significant pollution levels(from medium to very high)in estuarine and coastal areas.Multi-statistical analysis indicated land-based inputs(tourists,local waste,agriculture,and industry)dominated the studied regions.The study emphasized the potential impact of MPs pollution on aquatic ecosystems,emphasizing the need for effective management,mitigation methods,continuous surveillance,and thorough evaluation.
文摘This study aims, first, to examine the limit for tolerance to lower salinity by an oceanic sea skater, Halobates micans, and , second, to make it clear whether exclusively fresh water Halobatinae species, Metrocoris histrio has salinity tolerance. Adults of H. micans were collected using Neuston Net from the starboard side of R/V MIRAI on a fixed station at 8°S, 80°E, whereas those of M. histrio were collected from a small pond filled with a spring fresh water in Kochi (33°N, 133°E), Japan. Time in survival was measured in starved condition under several salinity conditions: 0‰, 2‰, 4‰, 6‰, 8‰, 9‰ and 10‰ for H. micans;0‰, 5‰, 10‰, 12.5‰, 15‰ for M. histrio. Half of adults were in coma due to lower salinity under 10‰ and time in survival was less than 10 hours under less than 4‰ for H. micans. Time in survival was half at 5‰ of 80 hours on average at 0‰ as a control and less than 10 hours at 10‰ or higher salinity for M. histrio. Relatively flexible osmo-regulation ability by H. micans would be related to wide variety of salinity condition of surface oceanic water, whereas very limited tolerance even to lower salinity of 5‰ may be permitted by the no chances to be exposed to brackish water in natural habitats of M. histrio. This study showed that salinity tolerance of Halobatinae species would reflect, directly, the salinity condition of their habitats.
文摘To address various fisheries science problems around Japan, the Japan Fisheries Research and Education Agency (FRA) has developed an ocean forecast system by combining an ocean circulation model based on the Regional Ocean Modeling System (ROMS) with three-dimensional variational analysis schemes. This system, which is called FRA-ROMS, is a basic and essential tool for the systematic conduct of fisheries science. The main aim of FRA-ROMS is to realistically simulate mesoscale variations over the Kuroshio-Oyashio region. Here, in situ oceanographic and satellite data were assimilated into FRA-ROMS using a weekly time window. We first examined the reproducibility through comparison with several oceanographic datasets with an Eulerian reference frame. FRA-ROMS was able to reproduce representative features of mesoscale variations such as the position of the Kuroshio path, variability of the Kuroshio Extension, and southward intrusions of the Oyashio. Second, using a Lagrangian reference frame, we estimated position errors between ocean drifters and particles passively transported by simulated currents, because particle tracking is an essential technique used in applications of reanalysis products to fisheries science. Finally, we summarize recent and ongoing fisheries studies that use FRA-ROMS and mention several new developments and enhancements that will be implemented in the near future.
文摘The PIRATA-SWE （Prediction and Research Moored Array in the Tropical Atlantic-Southwest Extension） was conceived in the early 2000s to gather observations necessary to improve the understanding of the variability of ocean-atmosphere interactions in the SACZ （South Atlantic Convergence Zone）, which are believed to influence South American climate. To properly monitor the SACZ, the preliminary design for the PIRATA-SWE array considered the mooring of four buoys, with the southernmost one in the sub-tropics. In 2005, three buoys were deployed in the tropical region. Four years later, in 2009, efforts were started to assemble and deploy a Brazilian prototype of the TAO/PIRATA Atlas （autonomous temperature line acquisition system） buoy-the Atlas-B. Finally, in April 2013 the first Atlas-B, nicknamed ＂Guariroba＂, was moored for a testing period at 28.5° S, 44° W, which is the site originally planned for the fourth PIRATA-SWE buoy. In early November 2013, after being detected adrift, the buoy with the upper 700 m part of the mooring line was rescued in an emergency operation. In June 2014, the bottom part was successfully recovered. A new deployment is planned for late 2014. This paper describes part of the learning process of adapting and building the Atlas-B buoy and presents a brief discussion of the data collected during the pilot deployment.
文摘The main purpose of this study is to investigate temperature preference for habitat of three species of oceanic sea skaters, Halobates micans, H. germanus and H. sericeus. For each of the three species, we examined the relationship between population density and surface water and air temperatures in the sampling sites during three science cruises in the tropical to temperate zone of the Pacific Ocean. A higher density of H. micans was observed in sites with higher water and air temperatures at 28℃?- 30℃?than that at site with lower temperatures of 23℃?- 28℃. A higher density of H. germanus was observed in sites with extremely high temperatures of 29.6℃?and 30℃?than that in sites with moderately high temperatures of 28℃?- 29℃?in the Pacific Ocean, while a relatively high density was observed in sites with a wide range of temperatures from 24℃?- 30℃?in the southern hemisphere Pacific Ocean. The relatively low temperature preference of 23℃?- 28℃?exhibited by H. sericeus may be related to its size as the smallest among the three species and its relatively wide latitudinal distribution ranging up to 40?N.
基金Supported by National Natural Science Foundation of China(Grant Nos.52275316,51905437,52305149)Nantong Municipal Research Fund for Advanced Ocean Institute of Southeast University(Grant No.KP202409)+3 种基金Jiangxi Provincial Key Laboratory of Forming and Joining Technology for Aerospace Components(Grant No.EL202280325)State Administration for Market Regulation(Grant No.2023MK042)Jiangsu Provincial Administration for Market Regulation(Grant No.KJ2023003)Jiangsu Province Special Equipment Safety Supervision Inspection Institute(Grant Nos.KJ(Y)202429,KJ(YJ)2023001)。
文摘Tool wear is a critical challenge in titanium alloy friction stir welding(FSW).Vortex flow-based FSW(VFSW)is a potential solution for this issue because the VFSW process uses a similar material to the base metal as the tool.In this study,TC4 titanium alloy was welded by VFSW for the first time.Parameter optimization of the vortex flow formation is first done,and then the weld formation and the joints'microstructure and mechanical performance are investigated at different traversing speeds.The results prove that the plunging velocity is the dominant factor in the vortex depth.A lower plunging speed is beneficial for the formation of a deeper vortex.Full penetration is achieved at traversing speeds of 50–120 mm/min at 300 r/min.At welding speed above 130 mm/min,insufficient penetration defects occur.In the heat affected zone,grain coarsening andβ-phase volume fraction increase arise,whereas,in the weld nugget,anα+βlamellar structure emerges.Under the optimized parameters,the joint tensile strength is nearly 98%of the base material,but the elongation decreases significantly.The oxides drawn into the weld by the vortex at the junction between the vortex and the base material are the main reason for the small elongation.This study proves that the VFSW process is feasible for titanium alloys.
基金This study was supported by the National Natural Science Foundation of China(42261008,41971034)the Natural Science Foundation of Gansu Province,China(22JR5RA074).
文摘Stable water isotopes are natural tracers quantifying the contribution of moisture recycling to local precipitation,i.e.,the moisture recycling ratio,but various isotope-based models usually lead to different results,which affects the accuracy of local moisture recycling.In this study,a total of 18 stations from four typical areas in China were selected to compare the performance of isotope-based linear and Bayesian mixing models and to determine local moisture recycling ratio.Among the three vapor sources including advection,transpiration,and surface evaporation,the advection vapor usually played a dominant role,and the contribution of surface evaporation was less than that of transpiration.When the abnormal values were ignored,the arithmetic averages of differences between isotope-based linear and the Bayesian mixing models were 0.9%for transpiration,0.2%for surface evaporation,and–1.1%for advection,respectively,and the medians were 0.5%,0.2%,and–0.8%,respectively.The importance of transpiration was slightly less for most cases when the Bayesian mixing model was applied,and the contribution of advection was relatively larger.The Bayesian mixing model was found to perform better in determining an efficient solution since linear model sometimes resulted in negative contribution ratios.Sensitivity test with two isotope scenarios indicated that the Bayesian model had a relatively low sensitivity to the changes in isotope input,and it was important to accurately estimate the isotopes in precipitation vapor.Generally,the Bayesian mixing model should be recommended instead of a linear model.The findings are useful for understanding the performance of isotope-based linear and Bayesian mixing models under various climate backgrounds.
文摘Water-related hazards, such as river floods, flash floods and droughts, are becoming more frequent in the Upper Chao Phraya River Basin, Thailand, due to climate change and urbanization, causing significant societal, economic, and environmental damage. This study supports decision-making for nature-based solutions (NBS) to address mitigate these hazards. Using multi-criteria decision analysis, simulation modeling, and spatial analysis, the study identified precipitation and river discharges as key hazard drivers. Mapping hazard severity at various scales, the findings suggest that expanding green areas and water storage can enhance water management and reduce hazard impacts. This research offers critical insights for NBS adoption in water-related risk reduction.
基金support from the National Natural Science Foundation of China (U1405212)the National Key Research and Development Program of China (2016YFD0300707)+1 种基金the Natural Science Foundation of Fujian Province, China (2017J01618)the 100 Talent Project from Fujian Province to Dr.Daniel J.Ebbole (Texas A&M University, USA)
文摘Rice blast disease, caused by Magnaporthe oryzae, threatens global food security. The rice blast pathosystem is a longstanding model system for understanding plant-microbe interactions. In order to elucidate the coevolution of the host and pathogen, and provide the appropriate methods for preventing or controlling rice blast disease, researchers have focused on the evolution of virulence factors and resistance genes. Thus far, more than 30 rice blast resistance（R） genes and 12 avirulence（Avr） genes have been cloned. This review summarizes the cloned rice blast R genes, cloned Avr genes of M. oryzae and the interaction between them. This discussion also considers some of the major unanswered questions concerning this pathosystem and the opportunities for future investigations.
基金The study was supported by the National Natural Science Foundation of China under contract No. 49976023 the Natural Science Foundation of Zhejiang Province under contract No. N29985.
文摘Based on the test data in dynamic water and static water, the main factors, which influence the fine sediment flocculation, are analyzed with a gray model method of correlation theory. It is shown that the main influencing factors are water temperature, settling time, salinity, grain size, sediment concentration and current velocity according to the correlation coefficients. Among them, the salinity and the sediment grain size are critical type influencing factors (CrTIF); the settling time, the sediment concentration and the velocity are continuous type influencing factors (CoTIF); and the water temperature has the characteristics of both. When the critical values of CrTIF are reached or exceeded, the fine sediments will be flocculated, but values of CrTIF will not influence the settlement strength of floes. The influence of CoTIF is continuous. The values of the CoTIF will not only influence the occurrence of flocculation but also the settlement strength of the floes.
文摘Highly fecund marine species with dispersive life-history stages often display large population sizes and wide geographic distribution ranges. Consequently, they are expected to experience reduced genetic drift, efficient selection fueled by frequent adaptive mutations, and high migration loads. This has important consequences for understanding how local adaptation proceeds in the sea. A key issue in this regard, relates to the genetic architecture underlying fitness traits. Theory predicts that adaptation may involve many genes but with a high variance in effect size. Therefore, the effect of selection on allele frequencies may be substantial for the largest effect size loci, but insignificant for small effect genes. In such a context, the performance of population genomic methods to unravel the genetic basis of adaptation depends on the fraction of adaptive genetic variance explained by the cumulative effect of outlier loci. Here, we address some methodological challenges associated with the detection of local adaptation using molecular approaches. We provide an overview of genome scan methods to detect selection, including those assuming complex demographic models that better describe spatial population structure. We then focus on quantitative genetics approaches that search for genotype-phenotype associations at different genomic scales, including genome-wide methods evaluating the cumulative effect of variants. We argue that the limited power of single locus tests can be alleviated by the use of polygenic scores to estimate the joint contribution of candidate variants to phenotypic variation.
