Перегляд за Автор "Bresler, Vladimir M."

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  • Ескіз
    Документ
    Acute toxicity of heavy metals for benthic epiphytic foraminifera Pararotalia spinigera (Le Calvez) and influence of seaweed-derived DOC
    (1995-10) Янко-Хомбах, Валентина Венедиктівна; Бреслер, Володимир М.; Янко-Хомбах, Валентина Венедиктовна; Бреслер, Владимир М.; Yanko-Hombach, Valentyna V.; Bresler, Vladimir M.
    The acute toxicity of cadmium, copper, and mercury to the benthic epiphytic foraminiferan Pararotaha spinigera (Le Calvez) was investigated using seven different vital cytophysiological and cytochemical methods. The ability to enzymatically hydrolyze the fluorogenic substrates fluorescein diacetate or fluorescein dibutyrate was the most sensitive method of LC50 value determination. The LC50 (24-h) values for cadmium, copper, and mercury determined by this assay with fluorescein diacetate was 0.56, 1.4, and 0.07 pM, respectively. The content of seaweed-derived dissolved organic carbon (DOC), measured by absorbance at 436 nm, produced a dramatic increase of LC50 values for the heavy metals in a dose-dependent manner. “Intact” epiphytic foraminifera attached to seaweeds are less sensitive to acute toxicity of cadmium, copper, and mercury than are “detached” foraminifera.
  • Ескіз
    Документ
    Chemical ecology; a new approach to the study of living benthic epiphytic Foraminifera
    (1995) Янко-Хомбах, Валентина Венедиктівна; Бреслер, Володимир М.; Янко-Хомбах, Валентина Венедиктовна; Бреслер, Владимир М.; Yanko-Hombach, Valentyna V.; Bresler, Vladimir M.
    Interactions of living benthic epiphytic foraminifera, Pararotalia spinigera and Rosalina macropora with unidentified natural organic compounds (UNOC) derived from decomposed seaweeds, heavy metal ions and three tracer xenobiotics, acridine orange (AO), neutral red (NR) and fluorescein (FLU), were investigated. A number of defense mechanisms against xenobiotics were discovered in the foraminifera studied. Presence of UNOC in seawater decreased acute toxicity of heavy metal ions for foraminifera. -from Authors