[Frequency distribution patterns of HLA antigens, genes, and haplotypesin the migrant population of northwestern Russia in relation to time of residence in the region and sex differentiation].

Frequency distribution patterns of the HLA antigens, genes, and haplotypes at subloci A, B, and Cw were examined in 664 female and 765 male Slavs in dependence to the duration of their residence in the extreme conditions of the Magadan region. In the groups studied, no statistically significant differences in the frequencies of the corresponding genes and antigens were found. Analysis of gamete associations showed that positive and negative associations revealed in some cases were typical of the population of the region on the whole.

[Low level of variability of mitochondrial DNA in sea otter populations from Kamchatka and Komandor Islands].

Variation in populations of sea otter Enhydra lutris lutris from Komandor islands and Kamchatka was studied in segment b1-b2 of cytochrome b gene and in the control region (main noncoding region) of mitochondrial DNA (mtDNA) by means of restriction analysis. The total sample size was 59 animals. Polymorphism was recorded only in the control mtDNA region for one restriction endonuclease (MboI).

[Mitochondria DNA markers and genetic demographic processes in neolithic Europe].

Distribution patterns of mitochondrial DNA markers, BamHI-2/AvaII-5(3), BamHI-3/MspI-4, and BamHI-1/AvaII-5(3), and mitotypes with the control region corresponding to the Cambridge reference sequence in European and Middle Eastern populations are discussed with respect to the history of the European populations in the Neolith. It is suggested that distribution of mtDNA markers is associated with the Neolithic invasion of the Caucasoid populations from the Middle East to Europe in accordance with the "wave-of-advance" hypothesis of Ammerman and Cavalli-Sforza. However, genetic differences between regional European population groups indicate a more pronounced demic diffusion in the southeast of Europe, better correlated with the hypothesis of C.

[Variability of mitochondrial DNA in three groups of indigenous inhabitants of Northern Asia].

Sequence variants of the hypervariable region I of human mitochondrial DNA (mtDNA) of 125 individuals from three aboriginal population groups of northern Asia (Yakuts, Evens, and Koryaks) were analyzed. Unique types of mtDNA (mitotypes) were discovered in 80% of Koryaks, 78% of Evens, and 59% of Yakuts. The mitotypes observed were clustered into nine phylogenetically related groups, two of which, according to the data on the comparative analysis of Siberian and east Asian populations, were Koryak-specific, and one was Even-specific.

[Allozyme variation in the sea otter (Enhydra lutris L. 1758). Analysis of materials from animals that died on Bering Island in the winter of 1992/1993].

By means of polyacrylamide gel electrophoresis, 42 enzymes and five nonenzyme proteins presumably encoded by 62 loci were studied. The samples were taken from 72 sea otters (Enhydra lutris L.) that perished on Bering Island (Komandor Islands) in winter 1992-1993.

[Distribution among Europeans of types of mitochondrial DNA, detected in putative remains of Tsar Nicholas II].

The prevalence of two types of the mitochondrial DNA (mtDNA) control region defined in the members of the Russian Czar family was examined in Caucasoid populations (N = 1081). The frequency of the type 16126(C)-16294(T)-16296(T) in Caucasoids was less than 1%. The mitotype 16126(C)-16169(T)-16294(T)-16296(T) was not found in the populations studied.

[Polymorphism in region V of mitochondrial DNA in indigenous populations of northern Asia].

The insertion and deletion polymorphisms of region V of mitochondrial DNA (mtDNA) were studied in three indigenous populations of northern Asia: Yakuts, Evens, and Koryaks. In Evens and Koryaks, polymorphism was not found. In Yakuts, a 9-bp deletion and a 4-bp insertion were revealed in mtDNA region V.

[The origin of caucasoid BamHI-3/MspI-4 mitochondrial DNA marker].

According to the analysis of polymorphism of mitochondrial DNA (mtDNA) in eastern Slavs, the frequency of the BamHI-3/AvaII-9/MspI-4 and BamHI-3/AvaII-13/MspI-4 mitotypes are 14% and 3%, respectively. The mitotype BamHI-3/MspI-4 in relation to the (+)AluI/15606 variant was demonstrated to be identical in European populations. It is assumed that the unimodal distribution of the difference values between all pairs of nucleotide sequences of the control mtDNA region that correspond to the BamHI-3/MspI-4 mitogroup indicates an association between the increase of mitotypic diversity in this mitogroup and the exponential growth of European populations in the Neolithic period.

Physiologic adaptation changes of the "Bering Bridge" expedition participants.

Cardiorespiratory measurements were repeatedly performed on indigenous and Caucasian Soviet and American male team members of the Bering Bridge expedition which covered approximately 1280 km over a 61 day period. Significant baseline differences in cardiorespiratory functions at rest and during submaximal cycle ergometer exercise were noted between racial groups. Indigenous members had significantly lower mean vital lung capacity and oxygen consumption levels during submaximal exercise, but a greater systolic blood pressure response to exercise.

Some aspects of lipid metabolism and thyroid function in arctic ground squirrel, Citellus parryi during hibernation.

The increased blood levels of thyroid hormones as well as morphologic signs of high activity of thyroid gland were observed in arctic ground squirrel during hibernation. High thyroid activity could explain the characteristics of lipid metabolism observed in the studied species during hibernation-increased lipid unsaturation and decreased cholesterol/phospholipids molar ratio in plasma membranes. High blood concentrations of total lipids, cholesterol, and phospholipids in dormant animals is explained by the dissociation between thermogenic and lipotropic actions of thyroid hormones.

Formation of the capsule around Filicollis anatis (Acanthocephala) in its intermediate host.

Morphogenesis of the capsule around larvae of Filicollis anatis was studied by electron microscopy. The capsule is formed at early, middle, and late acanthella development. The inner layer is formed at the late acanthella stage apparently from material secreted via a system of hypodermal canals.

Differential neutron energy spectra measured on spacecraft in low Earth orbit.

Two methods for measuring neutrons in the range from thermal energies to dozens of MeV were used. In the first method, alpha-particles emitted from the 6Li(n,alpha)T reaction are detected with the help of plastic nuclear track detectors, yielding results on thermal and resonance neutrons. Also, fission foils are used to detect fast neutrons.

The ten year cycle of the willow grouse of Lower Kolyma.

The population of willow grouse (Lagopus lagopus) in the Lower Kolyma district of Yakutia, USSR, shows cycles of abundance with a period of about 10 years. Observations habe been made for 2-5 months each year since 1977. This paper attempts to explain why the period of population depression is so long (3-4 years) and why the peak population density is so high.

Effects of muscle electrostimulation during simulated weightlessness.

In a 45-day experiment test subjects were exposed to bed rest with their heads down at -4 degrees C. Twice a day their muscles of the stomach, back, femur, and shin were stimulated with electric current for 25-30 min. The value of muscle tension was close to their maximum voluntary contraction.