Modern methods of aquaculture in Japan: T. Kafuku and H. Ikenoe. Elsevier Science Publishers,Amsterdam and New York, 1983. Developments in Aquaculture and Fisheries Science,vol. 11. xii + 216 pp., US$59.50 (U.S.A. and Canada), Dfl.140.00 (rest of the world), ISBN 0-444-99674-5     

N.P. Wilkins 《Aquaculture (Amsterdam, Netherlands)》1984,40(1):95-96

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Comparison of freshwater and marine performances of all‐female diploid and triploid Atlantic salmon (Salmo salar L.)     

Deirdre Cotter  Vera O'Donovan  Alan Drumm  Nicola Roche  E Nigel Ling  & Noel P Wilkins 《Aquaculture Research》2002,33(1):43-53

The performance of all‐female diploid (AF2N) and triploid (AF3N) Atlantic salmon were compared in fresh water, under commercial production conditions in 1995 and 1996 year classes. The performance of the 1996 year class was also assessed for 14 months in a commercial sea farm. Freshwater mortality was higher in the triploid groups. The majority of losses occurred in the early stages of egg development and during the first feeding period, when the incidence of non‐feeding fry was consistently higher. In growth studies, although diploid fry were significantly heavier during first feeding there were no significant differences in weight between groups some 8 months after fertilization or in presmolt growth periods from February to April in 1996 and 1997. Smolting rates were high (range 93.5–95.3%) and the incidence of deformities was low (< 1%) in both groups. Marine survival was lower in the triploid group, largely as a consequence of higher losses sustained during a period of chronic stress, when triploid losses were 9% higher. Growth patterns were similar for the first 11 months in sea water. Although graded triploid salmon were heavier in January 1998 (AF3N 1.62 ± 0.033 kg, AF2N 1.46 ± 0.36 kg, P < 0.05), when the fish were harvested in May 1998 diploid salmon were significantly heavier than triploid salmon although there was no significant difference in weights after evisceration (AF3N 2.40 kg ± 0.04 AF2N 2.49 kg ±0.03). The increase in weight of the diploids between winter and harvest reflects the growth spurt that occurs in maturing fish in the spring. Overall yields of triploid salmon in salt water were lower as a result of inferior survival.  相似文献   

An analysis of intertaxa differences in sulfur concentration in angiosperms     

Neil Willey  Janine Wilkins 《植物养料与土壤学杂志》2006,169(5):717-727

Understanding the behavior of sulfur (S) in the soil‐plant system is important for crop production, for predicting the movement of the radioisotope ³⁵S in the environment, and for investigating the role of S in plant metabolism of xenobiotics. A database of relative mean S concentrations in 121 species of flowering plants was constructed using a Residual Maximum Likelihood (REML) procedure with new experimental data for 76 species and literature data for 57 species, there being 12 species in common. The relative mean S concentrations in plant species were normally distributed and their range greater than previously reported for S concentrations between plant species. There was a significant phylogenetic effect on S concentrations when they were analyzed using a nested ANOVA coded with a recent phylogeny of flowering plants. About 36% of the variance between species was associated with the rank of Order and above. At the rank of Order, S concentrations were Brassicales > Malphigiales > Lamiales > Rosales > Caryophyllales > Malvales > Poales > Fabales > Fagales > Asterales. Experiments to quantify intervarietal differences within Beta vulgaris, Triticum aestivum, and Cicer arietinum revealed that these reached a maximum in B. vulgaris at about 20% of those found at the species level and above. A comparison of relative mean S concentrations with previously reported relative mean concentrations for heavy metals suggested correlations between S and cadmium (Cd), and S and zinc (Zn). The frequency distributions and phylogenetic effects reported here are useful to understanding soil‐plant transfer of stable and radioactive S isotopes in agricultural and natural ecosystems and might aid investigations of plant response to xenobiotics.  相似文献   

Genetic variation in leaf epidermal cell size and shape in Lolium perenne     

P. W. Wilkins  C. O. Sabanci 《Euphytica》1990,47(3):233-239

Summary Six diploid perennial ryegrass populations, two diploid F₁ hybrid families and the autotetraploid cv. Tove were grown in a glasshouse and the mean length and mean width of epidermal cells on the abaxial leaf surface of young fully expanded leaves compared. The diploids varied in cell length by 26%, in cell width by 9% and in length: width ratio by 39%. The cells of cv. Tove were 25% longer and 12% wider than those of the highest ranking diploid and the length: width ratio 9% higher. The DNA contents per telophase root-tip cell nucleus of a large-celled and a small-celled diploid population were similar, suggesting that the variation in epidermal cell size among diploids was due to the action of specific genes and not to differences in genome size. The mean epidermal cell dimensions of four of the above populations growing as plots in a field trial employing three levels of fertiliser nitrogen and four harvesting frequencies were measured on three occasions. Varietal ranking in cell dimensions was consistent over the different managements and dates, and agreed well with the glasshouse results. The results indicate that measurements of leaf epidermal cell length and width can be useful aids both in breeding for herbage yield and in distinguishing varieties with similar flowering dates.  相似文献   

Point-Based Mark-Recapture Distance Sampling     

J. L. Laake  B. A. Collier  M. L. Morrison  R. N. Wilkins 《Journal of Agricultural, Biological & Environmental Statistics》2011,16(3):389-408

Avian surveys using point sampling for abundance estimation have either focused on distance sampling or more commonly mark-recapture to correct for detection bias. Combining mark-recapture and distance sampling (MRDS) has become an effective tool for line transects, but it has been largely ignored in point sampling literature. We describe MRDS and show that the previously published methods for point sampling are special cases. Using simulated data and golden-cheeked warbler (Dendroica chrysoparia) survey data from Texas, we demonstrate large differences in abundance estimates resulting from different independence assumptions. Data and code are provided in supplementary materials.  相似文献   

Use of radiography to identify keel bone fractures in laying hens and assess healing in live birds     

Richards GJ  Nasr MA  Brown SN  Szamocki EM  Murrell J  Barr F  Wilkins LJ 《The Veterinary record》2011,169(11):279

The aim of this study was to use radiography to assess and characterise naturally occurring keel bone fractures in laying hens and monitor live birds over several weeks to examine the healing process. Twenty-four Lohmann brown commercial laying hens with varying degrees of keel bone fracture were used in the study. Birds were radiographed regularly over six weeks and the radiographic features and changing appearance of keel bone fractures were evaluated. The radiographic characteristics of old and new fractures were categorised and indicated that 80 per cent of birds entering the study with new fractures had healed after 35 days and five birds had incurred new fractures irrespective of their original fracture status.  相似文献   

A differential lysis method for the isolation of Cowdria ruminantium DNA     

S C Wilkins  R E Ambrosio 《Veterinary microbiology》1990,25(1):39-44

In order to isolate pure Cowdria ruminantium DNA an enzymatic lysis procedure was used to lyse Cowdria-infected bovine endothelial cell cultures differentially. Infected host cells were treated with trypsin followed by DNase digestion and centrifugation. This method resulted in the isolation of intact Cowdria organisms and removed bovine DNA effectively.  相似文献   

Rationalisation of the mass spectrometric and gas chromatographic behaviour of organophosphorus pesticides: Part 1–substituted phenyl phosphorothioates     

John P. G. Wilkins 《Pest management science》1990,29(2):163-181

The mass spectrometric and gas chromatographic behaviour of a series of O,O-dialkyl O-(substituted phenyl) phosphorothioates, and some related compounds is reported. Several of these compounds are widely used as pesticides. Appraisal of these data has permitted an increased understanding of the influence of phenyl substituents on the appearance of the mass spectra of these compounds. In particular, the nature and extent of mass spectrometric ortho effects, which are associated with weak molecular ion intensity, and/or the generation of rearrangement ions are reported. Examples in which an understanding of these effects has been helpful in the identification of related compounds, such as technical impurities and degradation products, are given. Published mass spectrometric data for some of these compounds are critically appraised.  相似文献   

Use of hair root as a source of DNA for the detection of heterozygotes for recessive defects in cattle     

PJ HEALY  JA DENNIS  JF MOULE 《Australian veterinary journal》1995,72(10):392-392

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Antibacterial sensitivities of bacteria isolated from dogs with tracheobronchitis   总被引：3，自引：0，他引：3  

R J Wilkins  D R Helland 《Journal of the American Veterinary Medical Association》1973,162(1):47-50

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