k/n系统在（n,L,r,r）维修策略下的可用度   总被引：1，自引：0，他引：1  

贾秀芹  刘瑞元 《西南大学学报(自然科学版)》2011,33(9)

在(n,L,r,r)维修策略下研究了k/n系统.在部件失效的时间服从指数分布且故障部件维修时间服从伽玛分布的条件下给出了k/n系统的可用度.  相似文献   

周期FC群的几种Frattini性质     

张志让  李响  郭钦 《西南大学学报(自然科学版)》2011,33(4)

研究了周期FC群的Frattini性质,证明了局部p-幂零性、局部p-可解性和局部p-超可解性是周期FC群类的Frattini性质.  相似文献   

Local knowledge surveys with small-scale fishers indicate challenges to sawfish conservation in southern Papua New Guinea     

Michael I. Grant  William T. White  Yolarnie Amepou  Leontine Baje  Amy Diedrich  Dotty Ibana  Dick J. Jogo  Stanley Jogo  Peter M. Kyne  Owen Li  Ralph Mana  Nigel Mapmani  Anthony Nagul  Darcy Roeger  Colin A. Simpfendorfer  Andrew Chin 《水产资源保护:海洋与淡水生态系统》2021,31(10):2883-2900

1. Sawfish (Pristidae) are considered to be among the most threatened families of elasmobranch (sharks and rays). There is a need to gather information on the status of poorly known sawfish populations to assist in global recovery initiatives.
2. This study used interviews with local fishers to investigate the presence of sawfish in southern Papua New Guinea (PNG) and their interactions with and uses and values for small-scale fishers.
3. A range of sawfish size classes are still encountered throughout southern PNG, while juvenile largetooth sawfish Pristis pristis were additionally reported in the freshwater reaches of all rivers surveyed. Reports of large size classes in estuarine and marine environments provide an optimistic outlook that sawfish populations persist throughout southern PNG.
4. Most fishers that catch sawfish retain them for various uses including consumption and for the sale of meat, fins and occasionally rostra. Negative population trends including decreases in catch frequency and/or size classes were reported by 66% of interviewees, with the largest declines being reported in the Kikori River. The increasing technical capacity of small-scale fishers, their preference for gillnetting and the emerging market for teleost swim bladder (a high-value fishery product) present a major ongoing threat to sawfish in southern PNG. Furthermore, the tendency of fishers to kill or remove rostra from entangled sawfish results in high fishing mortality regardless of any use by the fisher.
5. This study indicates that considerable community engagement will be necessary to manifest any legislative actions or increased enforcement on international trade regulations for sawfish in PNG. This is due to traditional land and waterway ownership values throughout PNG and the local perception of sawfish as a traditional food resource rather than an animal of intrinsic biodiversity value as perceived by global conservationists. Future research should consider exploring culturally appropriate conservation initiatives that are likely to achieve engagement and participation from local fishers.

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Control of salmon pituitary hormone gene expression     

Fei Xiong  Ronald Chin  Zhiyuan Gong  Kunimasa Suzuki  Richard Kitching  Sonali Majumdar-Sonnylal  Harry P. Elsholtz  Choy L. Hew 《Fish physiology and biochemistry》1993,11(1-6):63-70

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Antioxidant intake from diet and supplements and elevated serum C-reactive protein and plasma homocysteine concentrations in US adults: a cross-sectional study     

Floegel A  Chung SJ  von Ruesten A  Yang M  Chung CE  Song WO  Koo SI  Pischon T  Chun OK 《Public health nutrition》2011,14(11):2055-2064

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Effect of organic-phase solvents on physicochemical properties and cellular uptake of astaxanthin nanodispersions     

Anarjan N  Tan CP  Ling TC  Lye KL  Malmiri HJ  Nehdi IA  Cheah YK  Mirhosseini H  Baharin BS 《Journal of agricultural and food chemistry》2011,59(16):8733-8741

A simplex centroid mixture design was used to study the interactions between two chosen solvents, dichloromethane (DCM) and acetone (ACT), as organic-phase components in the formation and physicochemical characterization and cellular uptake of astaxanthin nanodispersions produced using precipitation and condensation processes. Full cubic or quadratic regression models with acceptable determination coefficients were obtained for all of the studied responses. Multiple-response optimization predicted that the organic phase with 38% (w/w) DCM and 62% (w/w) ACT yielded astaxanthin nanodispersions with the minimum particle size (106 nm), polydispersity index (0.191), and total astaxanthin loss (12.7%, w/w) and the maximum cellular uptake (2981 fmol/cell). Astaxanthin cellular uptake from the produced nanodispersions also showed a good correlation with their particle size distributions and astaxanthin trans/cis isomerization ratios. The absence of significant (p > 0.05) differences between the experimental and predicted values of the response variables confirmed the adequacy of the fitted models.  相似文献   

Enhancement of viability of a probiotic Lactobacillus strain for poultry during freeze‐drying and storage using the response surface methodology     

Anahita KHORAMNIA  Norhani ABDULLAH  Siew Ling LIEW  Chin Chin SIEO  Kalavathy RAMASAMY  Yin Wan HO 《Animal Science Journal》2011,82(1):127-135

A rotatable central composite design (CCD) was used to study the effect of cryoprotectants (skim milk, sucrose and lactose) on the survival rate of a probiotic Lactobacillus strain, L. reuteri C10, for poultry, during freeze‐drying and storage. Using response surface methodology, a quadratic polynomial equation was obtained for response value by multiple regression analyses: Y = 8.59546 ? 0.01038 X₁ ? 0.09382 X₂ ? 0.07771 X₃ ? 0.054861 X₁² ? 0.04603X₃² ? 0.10938 X₁X₂. Based on the model predicted, sucrose exerted the strongest effect on the survival rate. At various combinations of cryoprotectants, the viability loss of the cells after freeze‐drying was reduced from 1.65 log colony forming units (CFU)/mL to 0.26–0.66 log CFU/mL. The estimated optimum combination for enhancing the survival rate of L. reuteri C10 was 19.5% skim milk, 1% sucrose and 9% lactose. Verification experiments confirmed the validity of the predicted model. The storage life of freeze‐dried L. reuteri C10 was markedly improved when cryoprotectants were used. At optimum combination of the cryoprotectants, the survival rates of freeze‐dried L. reuteri C10 stored at 4°C and 30°C for 6 months were 96.4% and 73.8%, respectively. Total viability loss of cells which were not protected by cryoprotectants occurred after 12 and 8 weeks of storage at 4°C and 30°C, respectively.  相似文献   

Experimental transmission of turkey viral hepatitis to day-old poults and identification of associated viral particles resembling picornaviruses.     

P N Klein  A E Castro  C U Meteyer  B Reynolds  J A Swartzman-Andert  G Cooper  R P Chin  H L Shivaprasad 《Avian diseases》1991,35(1):115-125

Turkey viral hepatitis (TVH) was experimentally reproduced in two experiments in 1-day-old poults. In the first experiment, an infectious inoculum was prepared from filtered yolk materials harvested from dead embryonating chicken eggs (ECE) previously inoculated with suspensions of liver and pancreas tissues collected from TVH-affected birds in commercial turkey flocks. One-day-old poults given a yolk-sac inoculation or oral gavage with this preparation developed lesions in the liver and pancreas characteristic of TVH at 20 days postinoculation (PI) in 60% and 14% of the experimentally infected birds, respectively. With the identical inoculum, embryo mortality occurred at 8 and 10 days PI in embryonating turkey eggs (ETE) inoculated into the yolk sac. In the second experiment, an infectious inoculum was prepared from filtered yolk materials from dead ETE harvested in the first experiment. One-day-old poults given a yolk-sac inoculation with this filtered yolk material developed lesions in the liver and pancreas within 5 days PI. At 20 days PI, 67% of the experimentally infected birds had similar lesions. With the inoculum given to these poults, embryo mortality occurred at 6, 8, and 10 days PI in ETE inoculated into the yolk sac. Virus particles 26-28 nm in diameter with icosahedral morphology typical of picornaviruses were identified by EM in the yolk sacs of ETE that died in both experiments, and inoculated ETE that died following passage of filtered suspensions of pancreatic tissues collected from affected birds in the first experiment.  相似文献   

Serological assay for swine erysipelas using nitrocellulose particles impregnated with an immunodominant 65 kDa antigen from Erysipelothrix rhusiopathiae.     

J C Chin  B Turner  G J Eamens 《Veterinary microbiology》1992,31(2-3):169-180

Pigs (n = 10) that were experimentally challenged with an arthritogenic isolate of Erysipelothrix rhusiopathiae (strain VRS 229; serotype 1a) developed arthritis in at least one of twelve major limb joints. Immunoblots using sera obtained from these pigs at necropsy revealed a major band of immunoreactivity against a subunit polypeptide of apparent molecular mass 65 kDa. The usefulness of the 65 kDa immunodominant subunit as an assay reagent in an ELISA test was examined by presentation of antigen impregnated onto nitrocellulose particles (AINP). This was prepared by electro-transfer of bacterial polypeptides from SDS-PAGE gels to nitrocellulose. Protein bands were visualized by staining with amido black and a strip of nitrocellulose bearing the 65 kDa band was excised and extracted with formic acid. Nitrocellulose particles impregnated with the 65 kDa antigen (65-AINP) were precipitated from solution by neutralization with ammonium hydroxide. 65-AINP was suspended in water and the optimum dilution for ELISA assay was determined by titration to be 0.1 A650 units. Sera from all pigs challenged with VRS 229 reacted against the 65-AINP antigen in the ELISA assay while sera from control, and experimental pigs prior to challenge, failed to do so. The 65-AINP antigen could also be used efficaciously to quantify serological reactivity of pigs experimentally infected with other strains of E. rhusiopathiae representing the three major serotypes (1a, 1b and 2) that are most commonly associated with swine erysipelas infections. Mouse immunizations with 65-AINP also confirmed that nitrocellulose particles bearing the immunodominant subunit antigen will elicit murine antibodies that are monospecific against this determinant.  相似文献   

Squamous-cell carcinoma of the pharyngeal cavity in a Jersey black giant rooster     

R P Chin  B C Barr 《Avian diseases》1990,34(3):775-778

Squamous-cell carcinoma of the pharyngeal cavity was diagnosed in a 3-year-old Jersey black giant male chicken. Grossly, the carcinoma was round with irregular edges, yellow-tan, cauliflower-like with a crusty surface, and attached to the roof and sides of the pharyngeal cavity. Histologically, the surface of the mass was covered by a dense mat of necrotic mucosa and inflammatory cells. A broad front of neoplastic cords consisting of squamous epithelial cells extended into the lamina propria. There was no evidence of vascular invasion or metastasis.  相似文献