Уточнить поиск
Результаты 1-10 из 2,428
Mutant characters of Knotted maize leaves are determined in the innermost tissue layers.
1990
Sinha N. | Hake S.
Variations in the fish catch composition in the Bay of St Vincent, New Caledonia, as determined by experimental trawling
1990
Kulbicki, M. | Wantiez, L. (ORSTOM, Noumea (New Caledonia))
Between December 1984 and April 1986, 85 hauls were performed during 4 cruises. The trawled fish represented 233 species and 59 families. Biomass and density estimates declined 13-fold between the first and last cruises. This decline is not due to the survey catch, nor is it likely to be due to trawling-induced changes in habitat. Natural causes are the most likely reason for the decline. The r-type species (Leiognathidae, Lethrinus nematacanthus) had the largest population fluctuations, whilst longer living and later reproducing species (Saurida undosquamis, large Upeneus spp.) had the smallest. Trophic structure is studied using 3 expressions: number of species, biomass and density per trophic group. Number of species pe trophic group was the most insensitive to changes in time and place, with density being the most sensitive. Study of the variations in trophic structure could help with the monitoring of major changes in fish populations caused by fishing or environmental changes.
Показать больше [+] Меньше [-][Alaric, a new soybean cultivar. The first semi-determined cultivar, registered in the French Catalogue, INRA obtention (1989)]
1990
Roumet, P. (Institut National de la Recherche Agronomique, Montpellier (France). Centre de Montpellier, Station d'Amelioration des Plantes)
Alaric, un soja de haute technologie. 1. soja semi-determine au Catalogue francais, obtention INRA (1989).
1990
Roumet P.
Size at maturity in the male crab Scylla serrata as determined by chela allometry and gonad condition.
1990
Prasad P.N. | Neelakantan B.
Residues of the herbicide tri-allate in preplant and pre-emergence treated triticale (X Triticosecale Wittmack) determined by gas chromatography
1990
Cessna, A.J. (Agriculture Canada, Research Station, Regina, Sask. S4P 3A2 (Canada))
Comparison of free fatty acid values with individually determined organic and inorganic acid concentrations in the extracts of Malaysian natural rubber
1990
Crafts, R.C. | Davey, J.E. | McSweeney, G.P. | Stephens, I.S. (Malaysian Rubber Producer's Research Association, Brickendonbury, Hertford (UK))
Free fatty acid (FFA) values are frequently taken to be a measure of the long-chain fatty acid content of rubber samples. However, from an analytical view-point, it is apparent that the acidity measured during this test could not be due, entirely, to acids containing more than ten carbon atoms. Ion chromatography and gas chromatography have been used to identify and quantify the acidic components of the acetone extract of natural rubber. The combined acid concentrations measured by these techniques account for more than 85 percent of the FFA value and, of this figure, low molecular weight organic and inorganic acids account for up to one half. It may be concluded that expressing the result of an FFA titration as 'stearic acid' can seriously over-estimate the quantity of long-chain fatty acids present in natural rubber and may mask important differences in the composition of both these and the low molecular weight materials.
Показать больше [+] Меньше [-]Presence of daminozide and its metabolite 1,1-dimethyl hydrazine in apples and appleproducts from the Dutch market determined by GLC-EC analysis
1990
Schee, H.A. van der (Keuringsdienst van Waren, Amsterdam (Netherlands). Regionale Inspectie Gezondheidsbescherming) | Verwaal, W.
Relationship among compositional data of fibrous by-products as determined by two different extractions in the detergent system of analysis. Influence on the prediction of the digestibility
1990
Rebole, A. | Alvira, P. | Gonzalez, G.
Both direct and sequential extractions in the detergent system of analysis were applied to some fibrous by-products (cereal and legume straws, legume bagasse, vine branch silage and poplar bark) to determine which gave the better prediction of the digestibility through the summative equation, and to study the interferences of fibre-bound nitrogen and tannins. Permanganate lignin gave a lower correlation than acid-detergent lignin when figures from direct and sequential extractions were compared. Fibre-bound nitrogen (as N X 6.25) was positively correlated to permanganate lignin, whereas tannins were positively correlated to acid-detergent lignin. Figures for permanganate lignin from sequential extraction and acid-detergent lignin from direct extraction gave a good prediction of in-vitro digestibility, when they were used in the summative equation. More research into lignin, tannins and the detergent system of analysis of fibrous by-products should be done in order to improve and clarify the prediction of digestibility.
Показать больше [+] Меньше [-]Effects of auxin and anoxia on the cell wall yield threshold determined by negative pressure jumps in segments of cowpea [Vigna unguiculata] hypocotyl
1990
Okamoto, H. (Nagoya Univ. (Japan). Faculty of Science) | Miwa, C. | Masuda, T. | Nakahori, K. | Katou, K.
