Domestication of horses fundamentally transformed long-range mobility and warfare1. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling2–4 at Botai, Central Asia around 3500 bc3. Other longstanding candidate regions for horse domestication, such as Iberia5 and Anatolia6, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 bc, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association7 between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 bc8,9 driving the spread of Indo-European languages10. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium bc Sintashta culture11,12.

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The angular, temperature and magnetic field dependences of Hall resistance  Н for the rare-earth dodecaboride solid solutions Tm 1-x Yb x B 12 have been studied in a wide vicinity of the quantum critical point (QCP) x C~0 .3. The measurements performed in the temperature range 1.9300 K on high quality single crystals allowed to find out for the first time in these fcc compounds both an appearance of the second harmonic contribution in  Н at QCP and its' enhancement under the Tm to ytterbium substitution and/or with increase of external magnetic field. When the Yb concentration x increases a negative maximum of a significant amplitude was shown to appear on the temperature dependences of Hall coefficient R H (T) for the Tm 1-x Yb x B 12 compounds. Moreover, a complicated activation type behavior of the Hall coefficient is observed 2 at intermediate temperatures for x0.5 with activation energies E g~2 00K and E a~5 5-75K in combination with the sign inversion of R H (T) at low temperatures in the coherent regime. The density of states renormalization effects are analyzed within the variation of Yb concentration and the features of the charge transport in various regimes (charge gap formation, intra-gap manybody resonance and coherent regime) are discussed in detail in Tm 1-x Yb x B 12 solid solutions. PACS: 75.40.Cx, 72.15.Gd

Based on low temperature resistivity, heat capacity and magnetization investigations we show that the unusually strong suppression of superconductivity in LuxZr1−xB12 BSC-type superconductors in the range x<0.08 is caused by the emergence of static spin polarization in the vicinity of nonmagnetic lutetium impurities. The analysis of received results points to a formation of static magnetic moments with µ ef f ≈3µB per Lu-ion. The size of these spin polarized nanodomains was estimated to be about 5Å.

The superconducting and normal state characteristics of yttrium hexaboride (YB6) have been investigated for the single crystals with a transition temperatures Tc ranging between 6 K and 7.6 K. The extracted set of microscopic parameters [the coherence length ξ(0) ∼ 320÷340Å, the penetration depth λ(0) ∼ 1100÷1600Å and the mean free path of charge carriers l = 31÷58Å, the Ginzburg-Landau-Maki parameters κ1,2(0) ∼ 3.3÷4.8 and the superconducting gap ∆(0) ∼ 10.3÷14.8 K] confirms the type II superconductivity in "dirty limit" (ξ≫l ) with a medium to strong electron-phonon interaction (the electron-phonon interaction constant λ e-ph = 0.93÷0.96) and s-type pairing of charge carriers in this compound [2∆(0)/kB Tc ≈ 4]. The comparative analysis of charge transport (resistivity, Hall and Seebeck coefficients) and thermodynamic (heat capacity, magnetization) properties in the normal state in YB6 allowed to detect a transition into the cageglass state at T * ∼ 50 K with a static disorder in the arrangement of the Y 3+ ions. We argue that the significant Tc variations in the YB6 single crystals are determined by two main factors: (i ) the superconductivity enhancement is related with the increase of the number of isolated vacancies, both at yttrium and boron sites, which leads to the development of an instability in the hexaboride lattice; (ii ) the Tc depression is additionally stimulated by the spin polarization of conduction electrons emerged and enhanced by the magnetic field in the vicinity of defect complexes in the YB6 matrix.