ix, 303 leaves : ill., tables, photos ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1976

Thesis (Ph. D.)--University of Adelaide, 1985. / Includes bibliographical references (leaves 142-164).

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1994. / Includes bibliographical references (leaves 133-135).

Thesis (Ph.D.) -- University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1976.

Thesis (M.S.), Natural Resources / Water Resources, University of Wisconsin--Stevens Point, 2004. / Includes bibliographical references (leaves 40-45).

Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaves 113-125). Also available on the World Wide Web.

Thèse (M.Sc.)--Université Laval, 2008. / Bibliogr.: f. 30-34. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 93-102).

The nitrates content in 12various sorts of vegetables and potatoes was measured in years 2005 - 2007 using nitrate ion selective electrode. From total number 539 of analyzed samples 72 samples exceeded the maximal limit concentration of nitrates. Most frequently non-permissible values were found in the kohlrabi (26 samples from 44), radish (18 from 45), potatoes (8 from 48), root parsley (4 from 26), red beet (4 from 27) and white cabbage (6 from 45). Absolutely highest content of nitrates was measured in kohlrabi 4 610 mg NO3-.kg-1(in fresh matter) and red beet 4 977 mg NO3-.kg-1. Although over 13 % of samples exceeded limits of nitrates given by law, in generally, can be assumed that positive factors from vegetables consumption play more important role than potential risc from possible nitrates overdosage.

This study reports the findings on the effect of nitrates and phosphates on the biomass and toxin production of various strains of the unicellular non-nitrogen fixing cyanobacterium, Microcystis aeruginosa. The occurrence of blooms of Microcystis aeruginosa and microcystin in freshwater impoundments across the globe has been on the increase lately due to increased levels of eutrophication, resulting in human and animal deaths and illness, as well as drinking and recreational water foulment. A range of environmental factors have been shown to effect growth and microcystin production. Existing literature however is somewhat contradictory as to the effects of these physical and chemical factors on toxin production. Therefore Microcystis aeruginosa strains were cultured under batch and continuous conditions to determine the effect of nitrate and phosphate concentrations and ratios on biomass and toxin production. Cultures were analysed with regards to internal nutrient stores, biomass production, nutrient depletion, photosynthetic efficiency and microcystin production. Results showed that microcystin production correlated to growth rate, photosynthetic efficiency and internal nitrogen stores and that an optimal N:P ratio was associated with microcystin levels, growth rate and photosynthetic efficiency. Results therefore led to the conclusion that the nitrogen, carbon, and phosphate balance within the cell is closely associated with microcystin production. Whether or not microcystin is produced to maintain this balance or produced as a function of this balance remains to be determined.