The ecological characteristics of four lizardfishes, Trachinocephalus myops, Saurida undosquamis, Saurida tumbil and Saurida elongata, were studied from specimens （910 T. myops, 454 S. un-dosquamis, 686 S. tumbil and...The ecological characteristics of four lizardfishes, Trachinocephalus myops, Saurida undosquamis, Saurida tumbil and Saurida elongata, were studied from specimens （910 T. myops, 454 S. un-dosquamis, 686 S. tumbil and 744 S. elongata） collected monthly in the southern Taiwan Straits from April 2005 to March 2006. The population dynamics of the four lizardfishes was also discussed by the comparison with the previous studies. All being composed of 7 a classes; the dominant group of T. myops and S. tumbil was 1–2 a, while S. undosquamis and S. elongate were 2–3 a. The total mortality coefficient Z and the fishing mortality F were at high as indicated by the exploitation ratio E（0.5）, and a large number of by-caught juvenile and young fishes showing that the stock of lizardfishes in this area was overexploited and the fishing gear was irrational. Compared with the previous studies, the maximum and mean fork length, body mass and age of the four lizard- fishes declined gradually, the lizardfishes populations were younger in age and smaller in size. The asymptotic fork length L ∞ decreased while increasing growth coefficient k, and age at the inflexion point of mass t r was younger compared with the previous studies. The declining of older ones has moderated the feeding competition and the younger ones grew faster. The larger mortality param-eters Z, M and F have revealed higher fishing pressure. The smaller change of the first mature fork length of female T . myops and the change from K selection pattern to r selection pattern of S. tumbil have indicated a more vulnerable fishery ecosystem in this area. The changes of ecological characteristics and population dynamics may be caused by over-exploitation of demersal fishes such as the lizardfishes, especially a large number of juvenile and young fishes by-catch by the current fishing gears and methods. Therefore, in addition to the traditional fishery management approach such as the minimum length-limit, ecosystem approach to fisheries management （EAF） should be taken to improve the practical marine ecosystem management, including increased fishing intensity of the non-economic species especially the feeding competitors of the lizardfishes and the conservation of the pelagic fishery population in the fisheries ecosystem, in order to restore the fishery population and achieve the sustainable use of the fishery stocks.展开更多
Scale effects and evaluation models are crucial to the accuracy of landscape ecological risk evaluation.However,most studies conduct these evaluations at a single scale or with a single model,ignoring potential scale ...Scale effects and evaluation models are crucial to the accuracy of landscape ecological risk evaluation.However,most studies conduct these evaluations at a single scale or with a single model,ignoring potential scale effects and changes in landscape patterns.To address this,we took the Leshan City in Sichuan Province of China as a study case.We determined that the optimal spatial granularity for the study area is 150 m by analyzing the sensitivities of eight landscape pattern indices such as landscape fragmentation,landscape spreading,and Shannon's diversity at different spatial granularities,and employing the inflection point identification method.Building on this,we constructed a landscape pattern index model(ERI model)and a landscape pattern index model coupled with the ecological process of soil erosion(SI-ERI model)by incorporating the natural geographic factors of the study area.We used the ERI and SI-ERI models to evaluate the landscape ecological risk of Leshan City across multiple scales,including ecological,administrative,and sample scales.After conducting overlay and spatial autocorrelation analyses of the multi-scale evaluation results,we determined that the administrative scale is optimal for evaluating landscape ecological risk in the study area.At this scale,we verified the accuracy and reliability of the two models'evaluation results against the actual ecological environment in typical areas within the study area.The findings indicated that the SI-ERI model provided more precise and accurate spatial characterization,effectively reflecting the actual landscape ecological risk of Leshan City.According to the SI-ERI model's evaluation results at the administrative scale,Leshan City's overall risk level is relatively low,with good ecological environmental quality.Low-risk areas constitute 56.16%and medium-low-risk areas make up 23.81%,aligning closely with the city's actual situation.This study thus offers a scientific basis and theoretical reference for managing ecological risks and planning urban development in Leshan City.展开更多
In this article, the biosynthetic pathways of storage oil accumulation in oilseed plants were briefly introduced, and the transcription factors, such as B3 do- main supeffamily genes, lecl gene, wril gene etc., and th...In this article, the biosynthetic pathways of storage oil accumulation in oilseed plants were briefly introduced, and the transcription factors, such as B3 do- main supeffamily genes, lecl gene, wril gene etc., and their important role in oil accumulation regulation was mainly elucidated. Overexpession of transcription factors as feasible ways of genetic manipulation to increase oJl content in oilseed crops are promising in a long-term perspective.展开更多
In ordet to maintain the dependability of system and meet the functional needof users dtsire, this paper introduces a survivability mechanism into embedded real-time system,and proposes a general comprehensive, approa...In ordet to maintain the dependability of system and meet the functional needof users dtsire, this paper introduces a survivability mechanism into embedded real-time system,and proposes a general comprehensive, approach based on a rigorous definition of survivability. Thisapproach permits a trade-off between the function and the cost of system development. It emphasizesthe ultradependable implementation of crucial function without demanding that of entire system.展开更多
基金Marine Public Welfare Project of China under contract Nos 200805065,200905019-6,200705029 and 200805064Chinese Off shore Investigation and Assessment under contract No.908-02-04008+1 种基金the Scientific Research Foundation of the Third Institute of Oceanography,SOA under contract No.2011006Marine Science Foundation for Young Scientist under contract No.2011143
文摘The ecological characteristics of four lizardfishes, Trachinocephalus myops, Saurida undosquamis, Saurida tumbil and Saurida elongata, were studied from specimens （910 T. myops, 454 S. un-dosquamis, 686 S. tumbil and 744 S. elongata） collected monthly in the southern Taiwan Straits from April 2005 to March 2006. The population dynamics of the four lizardfishes was also discussed by the comparison with the previous studies. All being composed of 7 a classes; the dominant group of T. myops and S. tumbil was 1–2 a, while S. undosquamis and S. elongate were 2–3 a. The total mortality coefficient Z and the fishing mortality F were at high as indicated by the exploitation ratio E（0.5）, and a large number of by-caught juvenile and young fishes showing that the stock of lizardfishes in this area was overexploited and the fishing gear was irrational. Compared with the previous studies, the maximum and mean fork length, body mass and age of the four lizard- fishes declined gradually, the lizardfishes populations were younger in age and smaller in size. The asymptotic fork length L ∞ decreased while increasing growth coefficient k, and age at the inflexion point of mass t r was younger compared with the previous studies. The declining of older ones has moderated the feeding competition and the younger ones grew faster. The larger mortality param-eters Z, M and F have revealed higher fishing pressure. The smaller change of the first mature fork length of female T . myops and the change from K selection pattern to r selection pattern of S. tumbil have indicated a more vulnerable fishery ecosystem in this area. The changes of ecological characteristics and population dynamics may be caused by over-exploitation of demersal fishes such as the lizardfishes, especially a large number of juvenile and young fishes by-catch by the current fishing gears and methods. Therefore, in addition to the traditional fishery management approach such as the minimum length-limit, ecosystem approach to fisheries management （EAF） should be taken to improve the practical marine ecosystem management, including increased fishing intensity of the non-economic species especially the feeding competitors of the lizardfishes and the conservation of the pelagic fishery population in the fisheries ecosystem, in order to restore the fishery population and achieve the sustainable use of the fishery stocks.
基金supported by grants from the Ministry of Science and Technology of the People’s Republic of China(Grant Nos.2019YFC1803500,2019YFC1803504)the Key R&D Projects of Sichuan Provincial Science and Technology Department(Grant Nos.2018SZ0298,2023YFS0390)+1 种基金the Bureau of Science and Technology Aba Qiang Tibetan Autonomous Prefecture(Grant Nos.R22YYJSYJ0004,R23YYJSYJ0010)Southwest University of Science and Technology Doctoral Program(23zx7175)。
文摘Scale effects and evaluation models are crucial to the accuracy of landscape ecological risk evaluation.However,most studies conduct these evaluations at a single scale or with a single model,ignoring potential scale effects and changes in landscape patterns.To address this,we took the Leshan City in Sichuan Province of China as a study case.We determined that the optimal spatial granularity for the study area is 150 m by analyzing the sensitivities of eight landscape pattern indices such as landscape fragmentation,landscape spreading,and Shannon's diversity at different spatial granularities,and employing the inflection point identification method.Building on this,we constructed a landscape pattern index model(ERI model)and a landscape pattern index model coupled with the ecological process of soil erosion(SI-ERI model)by incorporating the natural geographic factors of the study area.We used the ERI and SI-ERI models to evaluate the landscape ecological risk of Leshan City across multiple scales,including ecological,administrative,and sample scales.After conducting overlay and spatial autocorrelation analyses of the multi-scale evaluation results,we determined that the administrative scale is optimal for evaluating landscape ecological risk in the study area.At this scale,we verified the accuracy and reliability of the two models'evaluation results against the actual ecological environment in typical areas within the study area.The findings indicated that the SI-ERI model provided more precise and accurate spatial characterization,effectively reflecting the actual landscape ecological risk of Leshan City.According to the SI-ERI model's evaluation results at the administrative scale,Leshan City's overall risk level is relatively low,with good ecological environmental quality.Low-risk areas constitute 56.16%and medium-low-risk areas make up 23.81%,aligning closely with the city's actual situation.This study thus offers a scientific basis and theoretical reference for managing ecological risks and planning urban development in Leshan City.
基金Supported by Science and Technology Foundation of Guizhou Province [(2011)2089]Engineering Technology Research Center Building Fund of Guizhou Province ([2012]4006)Excellent Scientific and Educational Governor Fund of Guizhou Province ([2009]06)~~
文摘In this article, the biosynthetic pathways of storage oil accumulation in oilseed plants were briefly introduced, and the transcription factors, such as B3 do- main supeffamily genes, lecl gene, wril gene etc., and their important role in oil accumulation regulation was mainly elucidated. Overexpession of transcription factors as feasible ways of genetic manipulation to increase oJl content in oilseed crops are promising in a long-term perspective.
文摘In ordet to maintain the dependability of system and meet the functional needof users dtsire, this paper introduces a survivability mechanism into embedded real-time system,and proposes a general comprehensive, approach based on a rigorous definition of survivability. Thisapproach permits a trade-off between the function and the cost of system development. It emphasizesthe ultradependable implementation of crucial function without demanding that of entire system.
