The Eurasian heartland: a continental perspective on Y-chromosome diversity.

The nonrecombining portion of the human Y chromosome has proven to be a valuable tool for the study of population history. The maintenance of extended haplotypes characteristic of particular geographic regions, despite extensive admixture, allows complex demographic events to be deconstructed. In this study we report the frequencies of 23 Y-chromosome biallelic polymorphism haplotypes in 1,935 men from 49 Eurasian populations, with a particular focus on Central Asia. These haplotypes reveal traces of historical migrations, and provide an insight into the earliest patterns of settlement of anatomically modern humans on the Eurasian continent. Central Asia is revealed to be an important reservoir of genetic diversity, and the source of at least three major waves of migration leading into Europe, the Americas, and India. The genetic results are interpreted in the context of Eurasian linguistic patterns.

[The reversibility of the action of solar UV radiation on the growth of and on the level of growth regulators in barley plants]. / Ob obratimosti deistviia solnechnoi UF-radiatsii na rost i uroven' reguliatorov rosta v rasteniiakh iachmenia.

Effects of UV radiation on a growth regulators activity of barley plants were studied in the West Pamir at 2.320 m above sea level. Inhibition of plant growth in a highlands environment was discussed. Inhibition appears as either a change of stimulating for inhibitory activity or an increased activity of the growth inhibitors. The plant growth inhibition during a bush phase which is a more sensitive period of growth in barley plants is reversible.

[The effect of natural UV-radiation on the growth and activity of endogenous growth regulators in barley leaves]. / Deistvie estestvennoi UF-radiatsii na rost i aktivnost' éndogennykh reguliatorov rosta v list'iakh iachmenia.

The effect of natural UV-radiation on the growth of two barley varieties in the Pamir highlands was investigated. It was found that UV-radiation, whose portion in the light structure of that region was high, inhibited the growth of barley stems. The growth processes were inhibited via involvement of growth stimulants and inhibitors. UV-radiation suppressed endogenous stimulants of indole nature. Growth inhibitors proved resistant to UV-radiation.