It is technically difficult to acquire large-field images under the complexity and cost restrictions of a diagnostic and instant field research purpose. The goal of the introduced large-field imaging system is to achieve a tolerable resolution for detecting microscale particles or objects in the entire image field without the field-curvature effect, while maintaining a cost-effective procedure ...

The protozoan Paramecium caudatum was examined under normal conditions versus aside a switched-on GSM telephone (900 MHz; 2 Watts). Exposed individuals moved more slowly and more sinuously than usual. Their physiology was affected: they became broader, their cytopharynx appeared broader, their pulse vesicles had difficult in expelling their content outside the cell, their cilia less efficiently...

Parasitic infection can modify host mobility and consequently their dispersal capacity. We experimentally investigated this idea using the ciliate Paramecium caudatum and its bacterial parasite Holospora undulata. We compared the short-distance dispersal of infected and uninfected populations in interconnected microcosms. Infection reduced the proportion of hosts dispersing, with levels differi...

Membrane vesicles with a high mating reactivity were obtained from cilia of Paramecium caudatum by treatment with a solution containing 2 M urea and 0.1 mM Na2-EDTA. All processes of conjugation were induced in cells of the complementary mating type by approximately 10 mug/ml proteins of the vesicles. Electron microscope observation showed that the membrane vesicles have a diameter of 100-150 n...

Mating-reactive cells of Paramecium multimicronucleatum attach to a polystyrene surface (Falcon 10070 culture dishes) irrespective of extracellular ion concentration and swimming velocity. This attachment is induced in cells that are not mating-reactive by treatment with purified immunoglobulin G from antiserum, which blocks cells from mating or from antiserum prepared against the surface-local...

The ciliate Paramecium caudatum possesses an excitable cell membrane whose action potentials (APs) modulate the trajectory of the cell swimming through its freshwater environment. While many stimuli affect the membrane potential and trajectory, students can use current injection and extracellular ionic concentration changes to explore how APs cause reversal of the cell's motion. Students examin...

Some media are described which inhibit bacterial growth, but are favorable to protozoan development. A purification technique, which takes advantage of geotropic responses, was devised and used successfully with 7 species of protozoa, including flagellates and ciliates. The method was also used with a Spirillum. For one flagellate which could not be purified in this manner, a procedure involvin...