New class of turbulence in active fluids.

Turbulence is a fundamental and ubiquitous phenomenon in nature, occurring from astrophysical to biophysical scales. At the same time, it is widely recognized as one of the key unsolved problems in modern physics, representing a paradigmatic example of nonlinear dynamics far from thermodynamic equilibrium. Whereas in the past, most theoretical work in this area has been devoted to Navier-Stokes flows, there is now a growing awareness of the need to extend the research focus to systems with more general patterns of energy injection and dissipation.

Transition between saturation regimes of gyrokinetic turbulence.

A gyrokinetic model of ion temperature gradient driven turbulence in magnetized plasmas is used to study the injection, nonlinear redistribution, and collisional dissipation of free energy in the saturated turbulent state over a broad range of driving gradients and collision frequencies. The dimensionless parameter L(T)/L(C), where L(T) is the ion temperature gradient scale length and L(C) is the collisional mean free path, is shown to parametrize a transition between a saturation regime dominated by nonlinear transfer of free energy to small perpendicular (to the magnetic field) scales and a regime dominated by dissipation at large scales in all phase space dimensions.

Nonuniversal power-law spectra in turbulent systems.

Turbulence is generally associated with universal power-law spectra in scale ranges without significant drive or damping. Although many examples of turbulent systems do not exhibit such an inertial range, power-law spectra may still be observed. As a simple model for such situations, a modified version of the Kuramoto-Sivashinsky equation is studied.

[Helminthic cenosis of does in regions of Bulgaria].

Studies were carried out on the species composition of helminths as found in does in individual region of the Rhodope and Balkan Mountains and in the northeast part of this country. A total of 28 helminth species were found, belonging to 8 families as follows: class Trematoda--one family with one species; class Cestoda--one family with one species; and class Nematoda--6 families with 26 species. Most widespread were the species Chabertia ovina, with 82 per cent of infected animals; Spiculopteragia spiculoptera, with 74.

[Immunodiffusion studies of the complete somatic antigens of Paramphistomum sp. and Fasciola hepatica].

Investigations were carried out through the agar gel immunodiffusion test of complete somatic antigens of Paramphistomum sp. and Fasciola hepatica, using the respective homologic and heterologic hyperimmune rabbit sera. Differences were established in the spectrum and number of the produced precipitation lines - 6 to Paramphistomum and 4 to Fasciola.

[Fractionation of the Trichinella spiralis antigen and allergy diagnosis trails].

Experiments were carried out to fractionate an antigen of Trichinella spiralis with Sephadex G-50 and G-100. The specificty of the fractions has been followed up by means of the intradermal allergic reaction in six pigs, experimentally infected with Trichenalla spiralis, one with Trichocephalus suis and three, born by trichinellosis-affected sows. The second fraction has been tested also on four pigs, experimentally inoculated with Ascaris suum, nine--with Ascarsis suum and Oesophagostomum and 19 healthy pigs.

[Studies of the decontamination of the sewage from animal husbandry farms].

Investigations revealed that under the conditions prevailing in the districts of Sofia and .pernik Ascaris suum and Trichocephalus suis eggs remained viable at the conventional storage of liquid manure on the large farms for about a year, and Fasciola hepatica and Paramphistomum sp. eggs--for 2 to 3 months.

[Diagnostic value of the allergy test and precipitation reaction for the intravital diagnosis of trichinelliasis in swine].

A total of twenty-two experimentally infected pigs, presenting from 250 to 12000 Trichinellae per kilogram body weight, were studied by the skin allergy test, the tube precipitation reaction, and the double gel diffusion technique after Ouchterlony in the course of one year following infection. Use was made of a Trichinella antigen obtained by the Tanner and Gregory's modified method. Unspecific allergy reactions were observed in 2.

[Pathomorphological studies of trichocephaliasis in sheep].

The morphologic study of 22 sucking and weaned lambs (8 experimentally and 14 spontaneously infected with Trichocephalus) revealed that in its biologic development in the host Trichocephalus fixes itself firmly and penetrates deeply at its head and into the mucous membrane of the caecum and the large intestine. Besides, at these sites morphologic lesions in cases of strong infection have been established in the liver, kidneys, spleen, and lung. The desquamated epithelial cells and the erythrocytes found in the digestive canal of the parasite showed that sheep Trichocephalus sp.

[Studies of the humoral reactivity of piglets with experimental trichinelliasis].

Studied were pigs with experimental Trichinella spiralis infection by means of biopsy, the complement-fixation test, the tube precipitation reaction, the double diffusion technique after Ouchterlony, and the microimmunoelectrophoresis after Scheidegger, using an antigen obtained by the method of Tanner and Gregory as modified by the authors. Highest titers established by the c. f.