Proximity effect in superconducting bilayers and multilayers

Quantum Matter and Optic

‘To the land or to the sea' : diet and mobility in early medieval Frisia

This study investigated palaeodiet and population mobility in early medieval Frisia through the stable isotope analysis of individuals buried in the fifth–eighth century AD cemetery of Oosterbeintum, a terp site on the northern coast of the Netherlands. The results cast new light on the role of the northern Netherlands in trade and migration in the early medieval period, and have significance for the study of interaction and movement throughout the wider North Sea region. Bone collagen and tooth enamel from humans and animals were analyzed using carbon, nitrogen, oxygen, and strontium isotopes. δ13C and δ15N results indicated that the population had a terrestrial, C3-based diet. High δ15N values were observed in humans and fauna, which are probably related to the terp's salt-marsh location. The δ18O and 87Sr/86Sr data revealed a high proportion of non-locals buried at Oosterbeintum, some of whom had probably migrated from regions as distant and varied as Scandinavia and southern England. It is suggested that this immigration may be associated with Frisian maritime trading activities. New data are also presented from a small number of contemporaneous European sites

Survival and long-term maintenance of tertiary trees in the Iberian Peninsula during the Pleistocene. First record of Aesculus L.

The Italian and Balkan peninsulas have been places traditionally highlighted as Pleistocene glacial refuges. The Iberian Peninsula, however, has been a focus of controversy between geobotanists and palaeobotanists as a result of its exclusion from this category on different occasions. In the current paper, we synthesise geological, molecular, palaeobotanical and geobotanical data that show the importance of the Iberian Peninsula in the Western Mediterranean as a refugium area. The presence of Aesculus aff. hippocastanum L. at the Iberian site at Cal Guardiola (Tarrasa, Barcelona, NE Spain) in the Lower– Middle Pleistocene transition helps to consolidate the remarkable role of the Iberian Peninsula in the survival of tertiary species during the Pleistocene. The palaeodistribution of the genus in Europe highlights a model of area abandonment for a widely-distributed species in the Miocene and Pliocene, leading to a diminished and fragmentary presence in the Pleistocene and Holocene on the southern Mediterranean peninsulas. Aesculus fossils are not uncommon within the series of Tertiary taxa. Many appear in the Pliocene and suffer a radical impoverishment in the Lower–Middle Pleistocene transition. Nonetheless some of these tertiary taxa persisted throughout the Pleistocene and Holocene up to the present in the Iberian Peninsula. Locating these refuge areas on the Peninsula is not an easy task, although areas characterised by a sustained level of humidity must have played an predominant role

Groningen Radiocarbon Dates VI

This material was digitized as part of a cooperative project between Radiocarbon and the University of Arizona Libraries.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202

The first Pleistocene fossil records of Urtica kioviensis Rogow. (Urticaceae) and Potamogeton sukaczevii Wieliczk. (Potamogetonaceae) in the British Isles

Seeds of the extant Urtica kioviensis Rogow. (Urticaceae) and endocarps of the extinct Potamogeton sukaczevii Wieliczk. (Potamogetonaceae) were recorded in diverse plant macrofossil assemblages recovered from organic sediments exposed during excavations at Saham Toney, Norfolk, UK. Aminostratigraphical data show the sediments were deposited during the Ipswichian (Last Interglacial) Stage. Palynological data indicates deposition during the Carpinus pollen zone of the Ipswichian Stage—the latter part of pollen zone Ip IIb and Ip III. The records are noteworthy not only because they are the first in the British Pleistocene but also because of the geographical occurrences of these two species. Urtica kioviensis is absent from the British flora today and has a modern range in central and eastern Europe (only extending as far west as north–east Germany and Denmark), while the extinct Potamogeton sukaczevii has only been recovered from Late Pleistocene sediments in Belarus, Lithuania, Poland and western Russia. The presence of U. kioviensis along with other exotic species to the British Isles (e.g. Najas minor L. and Salvinia natans L., which today have central and southern ranges in Europe and in the case of S. natans occurs on other continents) may point to more continental conditions or warmer summer conditions during the second half of the Ipswichian Stage in southern Britain. No modern analogues occur in Britain for the assemblages recovered from Saham Toney. Evidence of colder winters or at least warmer summers at the time of deposition does not support the view that sea-level peaked in the Carpinus zone of the Eemian Stage (correlated with the Ipswichian Stage) associated with increased oceanicity. Southern Britain would have been under the influence of the Atlantic Ocean and a degree of oceanicity is supported by the presence of two thermophilous taxa, Hedera and Ilex, in the pollen spectra from Saham Toney. Alternative explanations for the presence of these exotic species are that they were tolerating mild winters and cooler summers at the time of deposition or exploiting suitable micro-environments. The distribution of P. sukaczevii is probably an artefact of the distribution of expertise in the identification of Potamogeton fossil endocarps rather than having any palaeogeographic or palaeoclimatic significance. It is an extinct ancestor of the extant P. maackianus A. Benn, an eastern Asian pondweed. Its discovery in Britain encourages a reassessment of plant macrofossil assemblages from western Europe, which may lead to a consideration of the relationship between the Late Pleistocene vegetation of Europe and eastern Asia.Bioarchaeolog