29 research outputs found
Thermal-dependent growth characteristics for Cylindrospermopsis raciborskii (Cyanoprokaryota) at different light availabilities: methodological considerations
Worker reentry safety. VIII. The determination of urinary metabolites—An index of human and animal exposure to nonpersistent pesticides
Worker reentry safety. VII. A medical overview of reentry periods and the use of urinary alkyl phosphates in human pesticide monitoring
Worker reentry safety. IX. Techniques of determining safe reentry intervals for organophosphate-treated cotton fields
Onset of Ischemic Colitis Following Use of Electrical Muscle Stimulation (EMS) Exercise Equipment
Estimation of minimum sedimentary inoculum (akinete) pool of Cylindrospermopsis raciborskii: a morphology and life-cycle based method
Estimation of minimum sedimentary inoculum (akinete) pool of Cylindrospermopsis raciborskii: a morphology and life-cycle based method
Cylindrospermopsis raciborskii undergoes characteristic morphological changes during its annual population development. Primary filaments ( those that derive directly from the akinetes) possess the following morphological features: the trichomes have one or two acuminate ends; they are narrower (2.4 - 2.6 mum) than older filaments, their lengths vary in a wide range (from 40 to 300 mum); some of them are straight but others are slightly coiled even in populations that later consist exclusively of straight filaments; cell walls between the cells are not or only hardly visible; the filaments have a fine granulation but no gas-vacuoles, polyphosphate- or any other contrasting bodies are seen. The secondary filaments deriving from the first division of primary filaments are similar but with only one acuminate end. This way, the number of germinating akinetes can be estimated as the number of primary filaments + 1/2 number of secondary filaments. The described morphological method to estimate inoculum size of C. raciborskii has limitations. ( 1) The number of akinetes that we get in this way is only a minimum number since germination is not synchronous under field conditions and probably not each akinete germinates that is present in the sediments. ( 2) The method is applicable only if germination occurs suddenly ( relatively synchronously). This is often the case in a temperate region where germination is triggered by temperature. ( 3) The method cannot be used in tropical or subtropical lakes where water temperature is permanently rather high and akinetes do not develop or develop only very rarely. ( 4) Being an a posteriori method it cannot be used as predictive tool. Estimations for Lake Balaton are in a good agreement with results of studies with other methods ( germination in laboratory cultures and direct counting) and have the advantage that they do not need time-consuming experimenting or difficult direct countings