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Biomedical subjects

J Ryba

Publications and source records attributed to J Ryba.

At least 19 recordsLinked to original sources
PubMed1986

Some features of the ecology of fleas inhabiting the nests of the suslik (Citellus citellus (L.)). I: Population dynamics, sex ratio, feeding, reproduction.

While studying the suslik fleas in artificial nests planted in free nature, significant changes in the population dynamics of N. setosa, C. simplex and C. orientalis (from the spring build up to the autumnal peak and the decrease of flea number until the next spring) were noted. The predominance of females in the spring period was recorded in N. setosa. Significant seasonal changes in the number of engorged females of N. setosa and C. simplex and of C. orientalis males (the increase of engorged specimens in the spring and summer) were demonstrated. A significant predominance of females with mature eggs in the spring and summer and their negligible number in the autumn were found in N. setosa and C. simplex.

Animals↗
PubMed1979

Experimental transmission of Tahyna virus (California group) to wild rabbits (Oryctolagus cuniculus) by mosquitoes.

Two wild rabbits (Oryctolagus cuniculus) were subcutaneously infected with a dose of 2.6 dex. i.c. LD50/0.02 ml of extraneurally passaged Tahyna virus strain "236". During the 24-72 hours interval p.i. viremia was demonstrated in both animals ranging from 1.0 to 3.42 dex. i.e. LD50/0.02. Mosquitoes Aedes vexans, which had fed on them, transmitted the virus to one of three other rabbits. During 24-96 hours interval after terminated feeding of infectious mosquitoes viremia was detected in this animal ranging from 0.49 to 4.08 dex i.c. LD50/0.02 ml. Seroconversion was revealed by means of plaque reduction neutralization test 11 days after infection.

Animals↗
PubMed1978

Virological examination of mosquito larvae from southern Moravia.

254 pools of 4,115 mosquito larvae belonging to nine species were examined by isolation experiments. The larvae were collected in breeding places in an inundated forest--a natural focus of Tahyna virus, in April, June and July 1974 and 1975. Tahyna virus was isolated from one pool of 10 Culiseta annulata larvae collected in July 1974. Ecological questions concerning this finding are discussed.

Aedes↗
PubMed1976

Dynamics of the natural focus of Tahyna virus in southern Moravia and species succession of its vectors, the mosquitoes of the genus Aedes.

The paper deals with the occurrence of Aedes mosquitoes in southern Moravia and with Tahyna virus infection rates for them in 1972; a comparison of the data from previous years reveals the dynamics of the natural focus under long-term study. A total of 13,204 mosquitoes of the genus Aedes was processed in 122 tests, resulting in 17 Tahyna virus strains isolates. As concerns the valence of the natural focus, the most important was the inundated forest in the Drnholec locality. Infection rates for the mosquitoes were also determined in various microbiotopes of the said locality. A. cinereus, from which Tahyna virus was first isolated in the summer of 1972, was much more numerous than in the preceding seasons studied, indicating its important role as vector of Tahyna virus. The cell line of Aedes albopictus was demonstrated to be susceptible enough for virus detection from mosquitoes collected in the field.

Aedes↗