The study aims to determine the effects of graded farming on growth performance and non-specific immunity factors of shrimp Litopenaeus vannamei Boone. Three size groups of shrimp, i.e., the small size group [Gs, with...The study aims to determine the effects of graded farming on growth performance and non-specific immunity factors of shrimp Litopenaeus vannamei Boone. Three size groups of shrimp, i.e., the small size group [Gs, with an average body length （BL） of （3.04 ± 0.36） cm and body weight （BW） （0.412± 0.35） g], the large group [GL, with a BL of （4.29±0.55） cm and BW of （1.098 ±0.42） g], and the ungraded group [Gm, with a BL of （3.47±0.81） cm and BW of （0.611 ±0.79） g], were reared under the same conditions for 8 wk. Growth performance and non- specific immunity factors were measured. The results showed that BW gain, biomass gain and the specific growth rate of body length （SGRL） were significantly influenced by size grading （one-way ANOVA, P 〈 0.05）. The peroxidase （POD） and antibacterial （Ua） activities of GL were lower than those of G. Superoxide dismutase （SOD） and lysozyme （U1） activities of Gm were lower than those of G. No significant difference （P = 0.121 〉 0.05） was found on phenoloxidase （PO） activity among the three size groups. Synthetically, size grading could enhance growth and rearing efficiency, and did not have a significant influence on the immunity of L. vannamei Boone. Therefore, graded fanning in L. vannamei Boone was feasible in the culture practice.展开更多
To effective prevent and control the disease of Penaeus vannamei Boone in Hainan Province, the morphology, cultural characteristics, physiological and biochemical reactions of the dominant strain isolated from the hep...To effective prevent and control the disease of Penaeus vannamei Boone in Hainan Province, the morphology, cultural characteristics, physiological and biochemical reactions of the dominant strain isolated from the hepatopanereas tissue of diseased P. vannamei were identified by conventional metheds, and 16S rDNA sequence was amplified by polymerase chain reaction （PCR） for sequencing analysis. Furthermore, artificial experimental infection was conducted to de- tect the pathogenicity of the isolate. Finally, the lytic ability of phage 28TM against the isolate was detected by in-vitro lysis test. The results showed that the isolate （HYRJ2013） was identified as Vibrio sinaloensis. There were similar symptoms with the natural incidence of P. vannamei when the isolate HYRJ2013 was used to infect P. vannamei by muscular injection. The median lethal dose （ LD50 ） was measured as 6.68 x 107 cfu/ml. Phage 28TM could lyse the isolate and be used for biological control. The results indicate that V. sinaloensis is an opportunistic pathogen to P. vannamei.展开更多
It is very important for gas-structure interaction between compressible ideal gas and elastic structure of space folded membrane booms during the inflatable deployment. In order to study this gas-structure interaction...It is very important for gas-structure interaction between compressible ideal gas and elastic structure of space folded membrane booms during the inflatable deployment. In order to study this gas-structure interaction problem, Arbitrary Lagrangian-Eulerian （ALE） finite element method was employed. Gas-structure interaction equation was built based on equilibrium integration relationship, and solved by operator split method. In addition, numerical analysis of V-shape folded membrane booms inflated by gas was given, the variation of inner pressure as well as deployment velocities of inflatable boom at different stage were simulated. Moreover, these results are consistent with the experiment of the same boom~ which shows that both ALE method and operator split method are feasible and reliable methods to study gas-structure interaction problem.展开更多
Closer ties with Hong Kong and Macao Hong Kong is set to benefit greatly from the launch of the proposed Guangdong FTZ,which is expected to be modeled after Shanghai’s,as it could be an expanded version of Shenzhen’...Closer ties with Hong Kong and Macao Hong Kong is set to benefit greatly from the launch of the proposed Guangdong FTZ,which is expected to be modeled after Shanghai’s,as it could be an expanded version of Shenzhen’s Qianhai special economic zone,scholars and experts said.Raymond Yeung,a senior economist at ANZ,told China Daily that Hong Kong stands to reap benefits from the Guangdong FTZ as展开更多
基金supported by the National High-TechR&D Program of China (2004BA526B02)the Natural Science Foundation of Qingdao Agricultural Univesity,China (610804)the High Level Talents Fund of Qingdao Agricultural University, China (630628)
文摘The study aims to determine the effects of graded farming on growth performance and non-specific immunity factors of shrimp Litopenaeus vannamei Boone. Three size groups of shrimp, i.e., the small size group [Gs, with an average body length （BL） of （3.04 ± 0.36） cm and body weight （BW） （0.412± 0.35） g], the large group [GL, with a BL of （4.29±0.55） cm and BW of （1.098 ±0.42） g], and the ungraded group [Gm, with a BL of （3.47±0.81） cm and BW of （0.611 ±0.79） g], were reared under the same conditions for 8 wk. Growth performance and non- specific immunity factors were measured. The results showed that BW gain, biomass gain and the specific growth rate of body length （SGRL） were significantly influenced by size grading （one-way ANOVA, P 〈 0.05）. The peroxidase （POD） and antibacterial （Ua） activities of GL were lower than those of G. Superoxide dismutase （SOD） and lysozyme （U1） activities of Gm were lower than those of G. No significant difference （P = 0.121 〉 0.05） was found on phenoloxidase （PO） activity among the three size groups. Synthetically, size grading could enhance growth and rearing efficiency, and did not have a significant influence on the immunity of L. vannamei Boone. Therefore, graded fanning in L. vannamei Boone was feasible in the culture practice.
基金Supported by the Colleges and Universities Scientific Research Projects of the Education Department of Nation(201311810046)Health Department Project of Hainan Province(QW2013 ZU-053)the Colleges and Universities Scientific Research Projects of the Education Department of Hainan Medical University(HYCX201213)
文摘To effective prevent and control the disease of Penaeus vannamei Boone in Hainan Province, the morphology, cultural characteristics, physiological and biochemical reactions of the dominant strain isolated from the hepatopanereas tissue of diseased P. vannamei were identified by conventional metheds, and 16S rDNA sequence was amplified by polymerase chain reaction （PCR） for sequencing analysis. Furthermore, artificial experimental infection was conducted to de- tect the pathogenicity of the isolate. Finally, the lytic ability of phage 28TM against the isolate was detected by in-vitro lysis test. The results showed that the isolate （HYRJ2013） was identified as Vibrio sinaloensis. There were similar symptoms with the natural incidence of P. vannamei when the isolate HYRJ2013 was used to infect P. vannamei by muscular injection. The median lethal dose （ LD50 ） was measured as 6.68 x 107 cfu/ml. Phage 28TM could lyse the isolate and be used for biological control. The results indicate that V. sinaloensis is an opportunistic pathogen to P. vannamei.
基金supported by the National Natural Science Foundation of China (10902032)the National Key Laboratory Opening Funding of Advanced Composites in Special Environments (HIT.KLOF.2009035)
文摘It is very important for gas-structure interaction between compressible ideal gas and elastic structure of space folded membrane booms during the inflatable deployment. In order to study this gas-structure interaction problem, Arbitrary Lagrangian-Eulerian （ALE） finite element method was employed. Gas-structure interaction equation was built based on equilibrium integration relationship, and solved by operator split method. In addition, numerical analysis of V-shape folded membrane booms inflated by gas was given, the variation of inner pressure as well as deployment velocities of inflatable boom at different stage were simulated. Moreover, these results are consistent with the experiment of the same boom~ which shows that both ALE method and operator split method are feasible and reliable methods to study gas-structure interaction problem.
文摘Closer ties with Hong Kong and Macao Hong Kong is set to benefit greatly from the launch of the proposed Guangdong FTZ,which is expected to be modeled after Shanghai’s,as it could be an expanded version of Shenzhen’s Qianhai special economic zone,scholars and experts said.Raymond Yeung,a senior economist at ANZ,told China Daily that Hong Kong stands to reap benefits from the Guangdong FTZ as
