Method for Qualitative and Quantitative Analysis of Ancient Lead Enamel Using Laser Inducted Breakdown Spectroscopy

The method of laser induced breakdown spectroscopy (LIBS) was used in analysis of the archaeological enamel samples from the ancient settlement of Jochi Khan (XIV century). During the qualitative analysis, it was found that the elements of the enamel matrix are Si, Pb, K, Na, Mg, Ca, Al. The glaze color is due to the presence of copper and iron. Clustering by the k-means method revealed two groups of samples similar in composition of enamel, but differing in place of origin within the settlement. For the studied samples the semi-quantitative composition of glazes was established from the spectra of LIBS using a method based on the hypothesis of local thermodynamic equilibrium (LTE) and a chemometric approach (Projection to Latent Structures, PLS). Probabilistic deterministic design of experiment was used to search for pairs of element lines that are not subject to changes when the conditions for spectra registration vary, and to determine the coefficients in the equations based on LTR. Calculations using the PLC method were carried out in the “R” programming environment. The following content of the matrix elements was obtained in terms of the most stable oxides, %: SiO2 — 49–61, PbO — 23–31, MgO — 1.7–2.3, CaO — 4.6–6.9, Na2O — 4.1–5.3, K2O — 5.1–6.4, Al2O3 — 0.8–1.7, CuO — 0.32–0.4, Fe2O3 — 0.09–0.16. The results of both methods are generally consistent with each other. The inaccuracy between 4 parallel determinations were 15-24 % for LTE, and 9–14 % for PLS. Taking into account the data of semi-quantitative analysis, it was concluded that the division into two groups is based on a different ratio of copper and iron in enamel

Population genomics of post-glacial western Eurasia.

Western Eurasia witnessed several large-scale human migrations during the Holocene <sup>1-5</sup> . Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes-mainly from the Mesolithic and Neolithic periods-from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a 'great divide' genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 BP, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 BP, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a 'Neolithic steppe' cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations

The origins and spread of domestic horses from the Western Eurasian steppes

Analysis of 273 ancient horse genomes reveals that modern domestic horses originated in the Western Eurasian steppes, especially the lower Volga-Don region.Domestication of horses fundamentally transformed long-range mobility and warfare(1). However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling(2-4) at Botai, Central Asia around 3500 bc(3). Other longstanding candidate regions for horse domestication, such as Iberia(5) and Anatolia(6), 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 association(7) between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 bc(8,9) driving the spread of Indo-European languages(10). This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium bc Sintashta culture(11,12).Descriptive and Comparative Linguistic

Assessment of the oral microbiome in the development of recurrent oral aphthae in patients with gastrointestinal pathology

Chronic recurrent oral aphthae in residents living in an ecologically unfavourable region are characterized by a permanent course and prolonged recovery processes of regeneration of pathological elements of the oral mucosa. Using the microbiological method and modern test systems, it has been found that on the surface of aphthae an extremely diverse state of the oral microbiota is determined and its types are diverse. Trigger mechanisms have been determined. The role of representatives of various types of microorganisms-entero-cocci, staphylococci, streptococci, yeast-like fungi of the genus Candida (C. albicans) and obligate-anaerobes in the development of recurrent oral aphthae has been established. The data obtained can serve as an indication for the development of modern treatment and preventive measures regarding this category of patients. © 2019, Ediciones Medicas del Sur S.R.L. All rights reserved