Pseudo-First-Order Transition in Interacting Self-avoiding Walks and Trails

The coil-globule transition of an isolated polymer has been well established to be a second-order phase transition described by a standard tricritical O(0) field theory. We present Monte-Carlo simulations of interacting self-avoiding walks and interacting self-avoiding trails in four dimensions which provide compelling evidence that the approach to this (tri)critical point is dominated by the build-up of first-order-like singularities masking the second-order nature of the coil-globule transition.Comment: 4 pages with 2 figures included, CCP2001 submissio

The Eneolithic cemetery at Khvalynsk on the Volga River

The genetically attested migrations of the third millennium BC have made the origins and nature of the Yamnaya culture a question of broad relevance across northern Eurasia. But none of the key archaeological sites most important for understanding the evolution of Yamnaya culture is published in western languages. These key sites include the fifth-millennium BC Khvalynsk cemetery in the middle Volga steppes. When the first part of the Eneolithic cemetery (Khvalynsk I) was discovered in 1977-1979, the graves displayed many material and ritual traits that were quickly recognized as similar and probably ancestral to Yamnaya customs, but without the Yamnaya kurgans. With the discovery of a second burial plot (Khvalynsk II) 120 m to the south in 1987-1988, Khvalynsk became the largest excavated Eneolithic cemetery in the Don-Volga-Ural steppes (201 recorded graves), dated about 4500-4300 BCE. It has the largest copper assemblage of the fifth millennium BC in the steppes (373 objects) and the largest assemblage of sacrificed domesticated animals (at least 106 sheep-goat, 29 cattle, and 16 horses); and it produced four polished stone maces from well-documented grave contexts. The human skeletons have been sampled extensively for ancient DNA, the basis for an analysis of family relationships. This report compiles information from the relevant Russian-language publications and from the archaeologists who excavated the site, two of whom are co-authors, about the history of excavations, radiocarbon dates, copper finds, domesticated animal sacrifices, polished stone maces, genetic and skeletal studies, and relationships with other steppe cultures as well as agricultural cultures of the North Caucasus (Svobodnoe-Meshoko) and southeastern Europe (Varna and Cucuteni-Tripol'ye B1). Khvalynsk is described as a coalescent culture, integrating and combining northern and southern elements, a hybrid that can be recognized genetically, in cranio-facial types, in exchanged artifacts, and in social segments within the cemetery. Stone maces symbolized the unification and integration of socially defined segments at Khvalynsk.Khokhlov’s research was funded in part by grants from the Russian Foundation for Basic Research No18-09-00309) and the Russian Science Foun-dation No18-18-00137

The formation of human populations in South and Central Asia

By sequencing 523 ancient humans, we show that the primary source of ancestry in modern South Asians is a prehistoric genetic gradient between people related to early hunter-gatherers of Iran and Southeast Asia. After the Indus Valley Civilization's decline, its people mixed with individuals in the southeast to form one of the two main ancestral populations of South Asia, whose direct descendants live in southern India. Simultaneously, they mixed with descendants of Steppe pastoralists who, starting around 4000 years ago, spread via Central Asia to form the other main ancestral population. The Steppe ancestry in South Asia has the same profile as that in Bronze Age Eastern Europe, tracking a movement of people that affected both regions and that likely spread the distinctive features shared between Indo-Iranian and Balto-Slavic languages.N.P. carried out this work while a fellow at the Radcliffe Institute for Advanced Study at Harvard University. P.M. was supported by a Burroughs Wellcome Fund CASI award. N.N. is supported by a NIGMS (GM007753) fellowship. T.C. and A.D. were supported by the Russian Science Foundation (project 14-50-00036). T.M.S. was supported by the Russian Foundation for Basic Research (grant 18-09-00779) “Anthropological and archaeological aspects of ethnogenesis of the population of the southern part of Western and Central Siberia in the Neolithic and Early Bronze Age.” D.P., S.S., and D.L. were supported by European Research Council ERC-2011-AdG 295733 grant (Langelin). O.M. was supported by a grant from the Ministry of Education and Sciences of the Russian Federation No. 33.1907, 2017/Π4 “Traditional and innovational models of a development of ancient Volga population”. A.E. was supported by a grant from the Ministry of Education and Sciences of the Russian Federation No. 33.5494, 2017/BP “Borderlands of cultural worlds (Southern Urals from Antiquity to Early Modern period).” Radiocarbon dating work supported by the NSF Archaeometry program BCS-1460369 to D.Ken. and B.J.C. and by the NSF Archaeology program BCS-1725067 to D.Ken. K.Th. was supported by NCP fund (MLP0117) of the Council of Scientific and Industrial Research (CSIR), Government of India, New Delhi. N.Bo., A.N., and M.Z. were supported by the Max Planck Society. D.Re. is an Investigator of the Howard Hughes Medical Institute, and his ancient DNA laboratory work was supported by National Science Foundation HOMINID grant BCS-1032255, by National Institutes of Health grant GM100233, by an Allen Discovery Center grant, and by grant 61220 from the John Templeton Foundation