In the survey of fishery resources,the sampling design will directly impact the accuracy of the estimation of the abundance.Therefore,it is necessary to optimize the sampling design to increase the quality of fishery ...In the survey of fishery resources,the sampling design will directly impact the accuracy of the estimation of the abundance.Therefore,it is necessary to optimize the sampling design to increase the quality of fishery surveys.The distribution and abundance of fisheries resource estimated based on the bottom trawl survey data in the Changjiang River(Yangtze River)Estuary-Hangzhou Bay and its adjacent waters in 2007 were used to simulate the"true"situation.Then the abundance index of Portunus trituberculatus were calculated and compared with its true index to evaluate the impacts of different sampling designs on the abundance estimation.Four sampling methods(including fixed-station sampling,simple random sampling,stratified fixed-station sampling,and stratified random sampling)were simulated.Three numbers of stations(9,16 and 24)were assumed for the scenarios of fixed-station sampling and simple random sampling without stratification.While 16 stations were assumed for the scenarios with stratification.Three reaction distances(1.5 m,3 m and 5 m)of P.trituberculatus to the bottom line of trawl were also assumed to adapt to the movement ability of the P.trituberculatus for different ages,seasons and substrate conditions.Generally speaking,compared with unstratified sampling design,the stratified sampling design resulted in more accurate abundance estimation of P.trituberculatus,and simple random sampling design is better than fixed-station sampling design.The accuracy of the simulated results was improved with the increase of the station number.The maximum relative estimation error(REE)was 163.43%and the minimum was 49.40%for the fixed-station sampling scenario with 9 stations,while 38.62%and 4.15%for 24 stations.With the increase of reaction distance,the relative absolute bias(RAB)and REE gradually decreased.Resource-intensive area and the seasons with high density variances have significant impacts on simulation results.Thus,it will be helpful if there are prior information or pre-survey results about density distribution.The current study can provide reference for the future sampling design of bottom trawl of P.trituberculatus and other species.展开更多
Fishery-independent surveys can provide high-quality data and support fishery assessment and management.Optimization of sampling design is crucial to increase the quality of fishery surveys.Crab pots are important fis...Fishery-independent surveys can provide high-quality data and support fishery assessment and management.Optimization of sampling design is crucial to increase the quality of fishery surveys.Crab pots are important fishing gears used to catch crabs.We analyzed the impacts of sampling design of crab pots on the abundance of Portunus trituberculatus in the Changjiang(Yangtze)River estuary to the Hangzhou Bay and its adjacent waters in East China Sea.The crab pots were cylindrical,240 mm in height and 600 mm in diameter of the iron ring.Our sampling designs(including fixed-station sampling,simple random sampling,stratified fixed-station sampling,and stratified random sampling),three number of stations(9,16,and 24),and three numbers of crab pots(500,1000,and 3000)were simulated and compared with the“true”abundance that obtained from bottom trawl surveys in the study area in 2007.The scenarios with 16 stations were set in stratification as a control group for comparison with unstratified designs.Results show that simple random sampling can obtain more stable results than fixed-station sampling in the abundance estimation of P.trituberculatus.In addition,stratified sampling resulted in more accurate abundance than unstratified sampling.The accuracy of the simulated results improved with the increase of the number of stations.No remarkable differences in the results were found among the scenarios of different number of crab pots at each station.However,resource-intensive areas exerted great impacts on simulation results.Thus,prior information or pre-survey results about resource abundance and density distribution are necessary.This study may serve as a reference for future sampling designs of crab pots of P.trituberculatus and other species.展开更多
Diff erent sea cucumbers have diff erent preferred habitats and seasonal changes,which is still lack of detailed research.This study selects two common tropical sea cucumbers(Holothuria edulis and Stichopus chloronotu...Diff erent sea cucumbers have diff erent preferred habitats and seasonal changes,which is still lack of detailed research.This study selects two common tropical sea cucumbers(Holothuria edulis and Stichopus chloronotus)to explore the reasons that aff ect their habitat selection and seasonal changes,so as to provide support for the spatial planning of sea cucumbers reserve in coral reef area.The study area is a compound distribution area of living coral reefs and sandy bottom in the north of Wuzhizhou Island.The survey time is January,April-September,2019.Three fi xed transects(G,H,and Q)were selected to reveal the population ecological characteristics of them in the typical dry season(January,April,May,and June)and rainy season(July,August,and September).The variation range of density for H.edulis and S.chloronotus were 2.0-8.9 inds./10 m^(2) and 0.2-0.7 inds./10 m^(2),respectively.The population density in rainy season was signifi cantly higher than that in dry season(P<0.05).H.edulis tends to be distributed in deeper water.The distribution of H.edulis was signifi cant positively correlated with the sand coverage and sand continuity in G transect(P<0.05),and signifi cant negatively correlated with live coral coverage in three transects(P<0.01).The shift from dry season to rainy season is a key factor aff ecting their habitat preference.In dry season,the preferred habitats of S.chloronotus are small rock(SR),sand(S),and small coral reef(SCR),while the H.edulis is S,SR,and dead coral rubbles(DCR).In rainy season,the preferred habitats of S.chloronotus are shift to SCR and SR,while the H.edulis is SCR,DCR,and sand.展开更多
In this study, we present the preparation of stable 1T-WS2 ultrathin nanosheets with NH~ intercalation using a bottom-up hydrothermal method and the potential application of this material in light-induced photothermal...In this study, we present the preparation of stable 1T-WS2 ultrathin nanosheets with NH~ intercalation using a bottom-up hydrothermal method and the potential application of this material in light-induced photothermal cancer therapy. Our results revealed that nanosheets with a size of 150 nm were highly hydrophilic and exhibited strong light absorption and excellent photostability in the broad near-infrared wavelength region. The in vitro experimental results indicated good biocompatibility of the nanosheets. More notably, our in vivo antitumor experiments illustrated that light-induced photothermal ablation originating from irradiation of the 1T-WS2 nanosheets with an 808 nm laser could efficiently kill tumor cells; these effects were obtained not only at the cellular level but also in the living organs of mice. This result may lead to new applications of two-dimensional layered materials in novel photothermal therapies and other photothermal related fields.展开更多
基金The National Key Research and Development Program of China under contract No.2017YFA0604902the Science and Technology Project of Zhoushan under contract No.2017C41012。
文摘In the survey of fishery resources,the sampling design will directly impact the accuracy of the estimation of the abundance.Therefore,it is necessary to optimize the sampling design to increase the quality of fishery surveys.The distribution and abundance of fisheries resource estimated based on the bottom trawl survey data in the Changjiang River(Yangtze River)Estuary-Hangzhou Bay and its adjacent waters in 2007 were used to simulate the"true"situation.Then the abundance index of Portunus trituberculatus were calculated and compared with its true index to evaluate the impacts of different sampling designs on the abundance estimation.Four sampling methods(including fixed-station sampling,simple random sampling,stratified fixed-station sampling,and stratified random sampling)were simulated.Three numbers of stations(9,16 and 24)were assumed for the scenarios of fixed-station sampling and simple random sampling without stratification.While 16 stations were assumed for the scenarios with stratification.Three reaction distances(1.5 m,3 m and 5 m)of P.trituberculatus to the bottom line of trawl were also assumed to adapt to the movement ability of the P.trituberculatus for different ages,seasons and substrate conditions.Generally speaking,compared with unstratified sampling design,the stratified sampling design resulted in more accurate abundance estimation of P.trituberculatus,and simple random sampling design is better than fixed-station sampling design.The accuracy of the simulated results was improved with the increase of the station number.The maximum relative estimation error(REE)was 163.43%and the minimum was 49.40%for the fixed-station sampling scenario with 9 stations,while 38.62%and 4.15%for 24 stations.With the increase of reaction distance,the relative absolute bias(RAB)and REE gradually decreased.Resource-intensive area and the seasons with high density variances have significant impacts on simulation results.Thus,it will be helpful if there are prior information or pre-survey results about density distribution.The current study can provide reference for the future sampling design of bottom trawl of P.trituberculatus and other species.
基金Supported by the National Key Research and Development Program of China(No.2019YFD0901304)the Science and Technology Project of Zhoushan(No.2017C41012)。
文摘Fishery-independent surveys can provide high-quality data and support fishery assessment and management.Optimization of sampling design is crucial to increase the quality of fishery surveys.Crab pots are important fishing gears used to catch crabs.We analyzed the impacts of sampling design of crab pots on the abundance of Portunus trituberculatus in the Changjiang(Yangtze)River estuary to the Hangzhou Bay and its adjacent waters in East China Sea.The crab pots were cylindrical,240 mm in height and 600 mm in diameter of the iron ring.Our sampling designs(including fixed-station sampling,simple random sampling,stratified fixed-station sampling,and stratified random sampling),three number of stations(9,16,and 24),and three numbers of crab pots(500,1000,and 3000)were simulated and compared with the“true”abundance that obtained from bottom trawl surveys in the study area in 2007.The scenarios with 16 stations were set in stratification as a control group for comparison with unstratified designs.Results show that simple random sampling can obtain more stable results than fixed-station sampling in the abundance estimation of P.trituberculatus.In addition,stratified sampling resulted in more accurate abundance than unstratified sampling.The accuracy of the simulated results improved with the increase of the number of stations.No remarkable differences in the results were found among the scenarios of different number of crab pots at each station.However,resource-intensive areas exerted great impacts on simulation results.Thus,prior information or pre-survey results about resource abundance and density distribution are necessary.This study may serve as a reference for future sampling designs of crab pots of P.trituberculatus and other species.
基金Supported by the National Key R&D Project of China(No.2019YFD0901304)the National Natural Science Foundation of China(Nos.42076097,31760757)the National Natural Science Foundation of Hainan Province,China(No.2019RC070)。
文摘Diff erent sea cucumbers have diff erent preferred habitats and seasonal changes,which is still lack of detailed research.This study selects two common tropical sea cucumbers(Holothuria edulis and Stichopus chloronotus)to explore the reasons that aff ect their habitat selection and seasonal changes,so as to provide support for the spatial planning of sea cucumbers reserve in coral reef area.The study area is a compound distribution area of living coral reefs and sandy bottom in the north of Wuzhizhou Island.The survey time is January,April-September,2019.Three fi xed transects(G,H,and Q)were selected to reveal the population ecological characteristics of them in the typical dry season(January,April,May,and June)and rainy season(July,August,and September).The variation range of density for H.edulis and S.chloronotus were 2.0-8.9 inds./10 m^(2) and 0.2-0.7 inds./10 m^(2),respectively.The population density in rainy season was signifi cantly higher than that in dry season(P<0.05).H.edulis tends to be distributed in deeper water.The distribution of H.edulis was signifi cant positively correlated with the sand coverage and sand continuity in G transect(P<0.05),and signifi cant negatively correlated with live coral coverage in three transects(P<0.01).The shift from dry season to rainy season is a key factor aff ecting their habitat preference.In dry season,the preferred habitats of S.chloronotus are small rock(SR),sand(S),and small coral reef(SCR),while the H.edulis is S,SR,and dead coral rubbles(DCR).In rainy season,the preferred habitats of S.chloronotus are shift to SCR and SR,while the H.edulis is SCR,DCR,and sand.
文摘In this study, we present the preparation of stable 1T-WS2 ultrathin nanosheets with NH~ intercalation using a bottom-up hydrothermal method and the potential application of this material in light-induced photothermal cancer therapy. Our results revealed that nanosheets with a size of 150 nm were highly hydrophilic and exhibited strong light absorption and excellent photostability in the broad near-infrared wavelength region. The in vitro experimental results indicated good biocompatibility of the nanosheets. More notably, our in vivo antitumor experiments illustrated that light-induced photothermal ablation originating from irradiation of the 1T-WS2 nanosheets with an 808 nm laser could efficiently kill tumor cells; these effects were obtained not only at the cellular level but also in the living organs of mice. This result may lead to new applications of two-dimensional layered materials in novel photothermal therapies and other photothermal related fields.
