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Lallias, Delphine; Gomez-raya, L.; Haley, C. S.; Arzul, Isabelle; Heurtebise, Serge; Beaumont, A. R.; Boudry, Pierre; Lapegue, Sylvie. |
We have identified quantitative trait loci (QTL) in the flat oyster (Ostrea edulis) for resistance to Bonamia ostreae, a parasite responsible for the dramatic reduction in the aquaculture of this species. An F-2 family from a cross between a wild oyster and an individual from a family selected for resistance to bonamiosis was cultured with wild oysters injected with the parasite, leading to 20% cumulative mortality. Selective genotyping of 92 out of a total of 550 F-2 progeny (i.e., 46 heavily infected oysters that died and 46 parasite-free oysters that survived) was performed using 20 microsatellites and 34 amplification fragment length polymorphism primer pairs. Both a two-stage testing strategy and QTL interval mapping methods were used. The two-stage... |
Tipo: Text |
Palavras-chave: Statistical power; Survival analysis; QTL mapping; Disease resistance; Ostrea edulis. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6682.pdf |
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Beliaeff, Benoit; Burgeot, Thierry. |
Activity of 7-ethoxyresorufin-O-deethylase (EROD) in fish is certainly the best-studied biomarker of exposure applied in the field to evaluate biological effects of contamination in the marine environment. Since 1991, a feasibility study for a monitoring network using this biomarker of exposure has been conducted along French coasts. Using data obtained during several cruises, this study aims to determine the number of fish required to detect a given difference between 2 mean EROD activities, i.e. to achieve an a priori fixed statistical power (l-beta) given significance level (alpha), variance estimations and projected ratio of unequal sample sizes (k). Mean EROD activity and standard error were estimated at each of 82 sampling stations. The... |
Tipo: Text |
Palavras-chave: Biomonitoring; Estimation; EROD activity; Statistical power; Sample size; Sampling design. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00337/44787/44483.pdf |
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Chim, Liet; Castex, Mathieu; Pham, Dominique; Brun, Pierre; Lemaire, Pierrette; Wabete, Nelly; Schmidely, P; Mariojouls, C. |
The New Caledonia blue shrimp Litopenaeus stylirostris is commercially produced under semi-intensive rearing conditions. The size of the farming earthen ponds (510 ha) and the subsequent production constraints make it difficult to use them as experimental units for random experiments. Moreover, since every pond has its own characteristics, ponds' effects cannot be ruled out, thus making it hard to define true replicates. In order to design future experiments under conditions resembling those used in production, we evaluated the possible use of floating cages as experimental units with the aim of assessing treatment effects with a reasonable statistical power. To this end, two sets of floating cages were placed respectively in two different ponds in a... |
Tipo: Text |
Palavras-chave: Statistical power; Replicates; Pond experimentation; Floating cages; Litopenaeus stylirostris. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4363.pdf |
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