The temperature dependence is investigated of the rho (T) resistance in monocrystals of the HTSC compound Ba sub 0.6 K sub 0.4 BiO sub 3 with the critical temperature T sub c =30K in the temperature ...range of 4.2-300K. The experimental data are approximated well by the rho sub f (T) dependence of the type of the Block-Gruneisen law. This dependence is obtained within the framework of the classical model of electron-phonon interaction with using the phonon spectrum in the form of a sum of an acoustic branch with the Debay dispersion law and a far remote narrow optical peak.
In 1975-1978 and in 1985-1988 studies of species composition and number of Phlebotomus, R. opimus infestation with L. major, L. turanica and L. gerbilli as well as epidemic activity of the natural ...foci were performed in the Karshi steppe in Uzbekistan. Typical areas have been compared in the desert, oasis and desert land irrigated for cotton growing. A correlation has been established between the epidemic activity of the natural focus and the nature of epizootic development in R. opimus and species composition of vectors. On desert territories epizootic transmission throughout the whole season develops with the domination of one leishmania species (L. turanica) which is not pathogenic for human beings. Paraphlebotomus are the main vectors transmitting leishmania. In oases epizootic process assumes a two-phase course, with accumulation by the middle of the season L. major species pathogenic for human beings. It is transmitted by P. papatasi. With desert irrigation, the former Phlebotomus species is transformed into the latter one, with the predominance of P. papatasi. Epizootics acquire a stable two-phase nature.
Studies of land irrigation effect on Phlebotomus sandflies, carriers of Leishmania major (a zoonotic cutaneous leishmaniasis causative agent)--were performed for 15 field work periods, from 1967 to ...1981, at 18 sites in various natural areas of the Karshi Steppe (Uzbek SSR). Over 43500 sandfly specimen were caught and identified. Regularities in sandfly number changes, first of all, that of Ph. papatasi, after irrigation were determined, with respect to various proximity of great gerbils' settlements, where sandflies breed in the irrigated fields. Well-drained sites situated higher than irrigated fields are practically unaffected by irrigation, sandflies number and specific composition being practically unchanged. At the sites situated either on the same level with irrigated fields or 3-5 m lower the number of sandflies changes usually in 2 stages: 1) short-term increase in Ph. papatasi number at the very beginning of the irrigation period; 2) formation of stably high or low Phlebotomus numbers due to stabilization of hydrothermal regime in the holes of great gerbils.
