Alpha-decay half-life of 253Es in metallic Fe at temperatures between 4 K and 50 mK

It has been claimed recently that half-lives of radioactive nuclei embedded in metals would be significantly affected by electron screening provided by the metal. The effectwould further be strengthened at low temperatures. We have determined the half-life-of 253Es nuclei embedded in iron at temperatures between 4 K and 50 mK. Our results agree with the room temperature literature value within about 2% and show no dependence on temperature over a range of almost two orders of magnitude.status: publishe

Hyperfine field of einsteinium in iron and nuclear magnetic moment of 254Es

The angular distributions of γ rays and α particles from oriented 250Bk, 253,254Es, and 255Fm nuclei were investigated to extract hyperfine interaction information for these actinide impurities in an iron host lattice. The hyperfine field of einsteinium in iron was found to be |Bhf (EsFe|) = 396(32) T. With this value the magnetic moment of 254Es was then determined as |μ| = 4.35(41) μN.status: publishe

A space between two worlds: St. Petersburg in the early eighteenth century

In May 1703, Tsar Peter I of Russia is alleged to have led a small military foray to the Baltic coastline, near the mouth of the river Neva. Accounts of this occasion, both contemporary and retrospective, vary considerably on the precise chronology of the decision-making process and the question of whether the tsar himself was actually present. Regardless of the precise details, the area was claimed (or, some argue, reclaimed) in the name of Russia and plans were made to build a fortress in order to consolidate the Russian presence. This foundation and the associated myths, which have been explored by many writers and historians over the intervening centuries, feature in most discussions of St. Petersburg’s history. One such myth, which presents Peter creating his new city out of nothing, in a wilderness, was essentially poetic license on the part of later writers such as Vasilii Trediakovskii and Aleksandr Pushkin. In fact, the area was the site of a Swedish fortress known as “Nienschants,” the town of Nien, with a population of around four thousand, and a number of smaller settlements nearby that existed before the city was founded. Indeed, given the paucity of usable stone in the region, the ruins of the old fortress likely provided material used in the initial stage of St. Petersburg’s construction, particularly in the foundations of buildings

Genetic Heritage of the Balto-Slavic Speaking Populations: A Synthesis of Autosomal, Mitochondrial and Y-Chromosomal Data

The Slavic branch of the Balto-Slavic sub-family of Indo-European languages underwent rapid divergence as a result of the spatial expansion of its speakers from Central-East Europe, in early medieval times. This expansion–mainly to East Europe and the northern Balkans–resulted in the incorporation of genetic components from numerous autochthonous populations into the Slavic gene pools. Here, we characterize genetic variation in all extant ethnic groups speaking Balto-Slavic languages by analyzing mitochondrial DNA (n = 6,876), Y-chromosomes (n = 6,079) and genome-wide SNP profiles (n = 296), within the context of other European populations. We also reassess the phylogeny of Slavic languages within the Balto-Slavic branch of Indo-European. We find that genetic distances among Balto-Slavic populations, based on autosomal and Y-chromosomal loci, show a high correlation (0.9) both with each other and with geography, but a slightly lower correlation (0.7) with mitochondrial DNA and linguistic affiliation. The data suggest that genetic diversity of the present-day Slavs was predominantly shaped in situ, and we detect two different substrata: ‘central-east European’ for West and East Slavs, and ‘south-east European’ for South Slavs. A pattern of distribution of segments identical by descent between groups of East-West and South Slavs suggests shared ancestry or a modest gene flow between those two groups, which might derive from the historic spread of Slavic people