Taphonomic phenomenon of ancient hair from Glacial Beringia:perspectives for palaeoecological reconstructions

An accumulation of mammoth hair, discovered in the Bol'shaya Chukochya River valley (northeast Yakutia, Russia), was found to contain remains of terrestrial and aquatic organisms, including plants, insects, crustaceans, birds and mammals. Radiocarbon dating indicated that this post-mortem taphocoenosis represented multiple time periods. The mammoth hair was dated to older than 45 ka BP, the plants were dated to 12 750 +/- 50 a BP (which corresponds to a shift in the environmental conditions and landscapes during the formation of thermokarst in northeastern Russia) and the bird feathers were dated to 4115 +/- 40 a BP. A scenario of the formation of this fossil assemblage is proposed, covering the MIS 3-1 time range. The hair also yielded various Arctic branchiopod crustaceans, which inhabit shallow temporary water bodies and therefore are important for reconstruction of palaeoenvironments. The cladoceran subgenus Daphnia (Ctenodaphnia), currently absent from the Asian part of Beringia, is reported from this region for the first time. The study demonstrates that the discovered permafrostpreserved hair is a unique repository of Ice Age organisms.</p

The diacylglycerol kinase α/Atypical PKC/β1 integrin pathway in SDF-1α mammary carcinoma invasiveness

Diacylglycerol kinase α (DGKα), by phosphorylating diacylglycerol into phosphatidic acid, provides a key signal driving cell migration and matrix invasion. We previously demonstrated that in epithelial cells activation of DGKα activity promotes cytoskeletal remodeling and matrix invasion by recruiting atypical PKC at ruffling sites and by promoting RCP-mediated recycling of α5β1 integrin to the tip of pseudopods. In here we investigate the signaling pathway by which DGKα mediates SDF-1α-induced matrix invasion of MDA-MB-231 invasive breast carcinoma cells. Indeed we showed that, following SDF-1α stimulation, DGKα is activated and localized at cell protrusion, thus promoting their elongation and mediating SDF-1α induced MMP-9 metalloproteinase secretion and matrix invasion. Phosphatidic acid generated by DGKα promotes localization at cell protrusions of atypical PKCs which play an essential role downstream of DGKα by promoting Rac-mediated protrusion elongation and localized recruitment of β1 integrin and MMP-9. We finally demonstrate that activation of DGKα, atypical PKCs signaling and β1 integrin are all essential for MDA-MB-231 invasiveness. These data indicates the existence of a SDF-1α induced DGKα - atypical PKC - β1 integrin signaling pathway, which is essential for matrix invasion of carcinoma cells

Neurocognitive Dysfunction in Systemic Lupus Erythematosus: Association with Antiphospholipid Antibodies, Disease Activity and Chronic Damage

Introduction: Systemic lupus erythematosus (SLE) is characterized by frequent neuropsychiatric involvement, which includes cognitive impairment (CI). We aimed at assessing CI in a cohort of Italian SLE patients by using a wide range of neurocognitive tests specifically designed to evaluate the fronto-subcortical dysfunction. Furthermore, we aimed at testing whether CI in SLE is associated with serum autoantibodies, disease activity and chronic damage. Methods: Fifty-eight consecutive patients were enrolled. Study protocol included data collection, evaluation of serum level

The Eurasian Modern Pollen Database (EMPD), version 2

The Eurasian (nee European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60% from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).Peer reviewe

The Eurasian Modern Pollen Database (EMPD), version 2

The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019)Swiss National Science Foundation | Ref. 200021_16959

An ancient bison from the mouth of the Rauchua River (Chukotka, Russia)

An incomplete carcass of an extinct bison, Bison ex gr. priscus, was discovered in 2012 in the mouth of the Rauchua River (69°30'N, 166°49'E), Chukotka. The carcass included the rump with two hind limbs, ribs, and large flap of hide from the abdomen and sides, several vertebrae, bones of the forelimbs and anterior autopodia, stomach with its contents, and wool. The limb bones are relatively gracile, which is unusual in bison, and a SEM study of the hair microstructure suggests higher insulating capacity than in extant members of the genus. Additionally, mitochondrial DNA analyses indicate that the Rauchua bison belonged to a distinct and previously unidentified lineage of steppe bison. Two radiocarbon dates suggest a Holocene age for the bison: a traditional 14C date provided an estimate of 8030±70 14C yr BP (SPb-743) and an AMS radiocarbon date provided an age of 9497±92 14C yr BP (AA101271). These dates make this the youngest known bison from Chukotka. Analysis of stomach contents revealed a diet of herbaceous plants (meadow grasses and sedges) and shrubs, suggesting that the early Holocene vegetation near the mouth of the Rauchua River was similar to that of the present day: tundra-associated vegetation with undersized plants

The Effect of Hydromorphism on Soils and Soil Organic Matter during the Primary Succession Processes of Forest Vegetation on Ancient Alluvial Sands of the European North-East of Russia

The article considers the role of hydromorphism in the soil formation processes on ancient alluvial sandy deposits at the primary succession period. Soil organic matter was given special attention. The studies were carried out in the European north-east of Russia (the Komi Republic) in the middle taiga subzone in the territory of a building-sand quarry (61&deg;57&prime;35&Prime; N, 50&deg;36&prime;22&Prime; E) and background sites near the quarry. The authors analyzed the morphological structure of soil profiles, and the principal physical-chemical properties of mature and young soils forming under pine forests. Formation of forest litter and humus-accumulative horizons, as well as soil organic matter accumulation were thoroughly studied. Already in the fourth&ndash;fifth succession decades, the soils in a series of increasing hydromorphism actively demonstrated regularities that are normally characteristic of background soils, for example, increase in acidity, silt fraction, carbon and nitrogen reserves. Against moisture deficiency, the accumulation rate of organic carbon became slow and amounted to 0.07&ndash;0.11 t ha&minus;1 year&minus;1. The excessive soil moisture content increased the rate up to 0.38&ndash;0.58 t ha&minus;1 year&minus;1 due to the conservation of plant material in the form of peat. The upper 50-cm profile layer of young soil contains Corg stock 3&ndash;5 times less than that of background soils. The major soil-forming processes are litter formation and podzolization in drained conditions, litter formation in conditions of high moisture, and peat formation and gleization against excessive moisture

Environmental reconstruction inferred from the intestinal contents of the Yamal baby mammoth Lyuba (Mammuthus primigenius Blumenbach, 1799)

The article presents the results of a complex investigation of the intestinal content of the frozen mummy of a baby woolly mammoth (Mammuthus primigenius Blumenbach, 1799) found in 2007 in the Yamal Peninsula (Western Siberia). The mummy belongs to a female mammoth calf approximately 1-1.5 months of age, and it has been named “Lyuba”. Analysis of bone tissue yielded a 14C date of 41,910 (+550/-450) years ago. Analysis of detritus material from the large intestine yielded a 14C date of 41,700 (+700/-550) years ago. These dates practically coincide, thus denoting synchronism of the time of the baby mammoth’s death and the formation of its intestinal contents. This time correspond to the middle part of MIS 3, or the Middle Weichselian Pleniglacial. Pollen, phytolith, plant macrofossil and mineral analyses of the intestinal content were carried out. Reconstruction of the environment where the baby mammoth lived is given based on the intestinal content analyses. The data suggest that the baby mammoth lived in tundra-like landscapes dominated by grass-sedge communities with forbs and Betula nana.

An approach for spatial analysis on the medieval Ust-Voikar settlement (subarctic Western Siberia) using macroremains and non-pollen palynomorphs

&lt;p&gt;The settlement of Ust-Voikar is one of the unique multilayered archaeological sites of north-west Siberia. The settlement was inhabited in the late Middle Ages and the early modern period by the Ob Ugrian or northern Khanty ethnographic group. Due to the presence of a frozen cultural layer ruins of wooden residential buildings and other organic materials are well preserved. Plant macroremain, pollen and non-pollen palynomorph (NPP) analyses were applied to samples of the cultural layer from different parts of buildings and from space between them to establish the vegetation cover, plants used by the population, and differences between functional zones in the buildings. For the first time, the NPP analysis combined with statistical methods were used to clarify the settlement planning and human economic activity. Plant communities around the Ust-Voikar settlement were typical for the northern taiga subzone, some settlement's areas were overgrown with weed vegetation. Residents did not engage in agriculture and used local plant resources for construction, medicinal and food purposes. According to macroremain and NPP data were reconstructed (i) the use of spruce branches and cereal bedding indoors and outdoors on wet sites; (ii) the careful use of fire indoors; (iii) the presence of animals indoors; and (iv) whipworm infection. The cluster analysis and principal component analysis of NPPs helped to clarify the planning affiliations of several samples with the unclear origin and to suggest ways in which archaeological objects were used by the inhabitants.&lt;/p&gt

The European Modern Pollen Database (EMPD) project

Modern pollen samples provide an invaluable research tool for helping to interpret the quaternary fossil pollen record, allowing investigation of the relationship between pollen as the proxy and the environmental parameters such as vegetation, land-use, and climate that the pollen proxy represents. The European Modern Pollen Database (EMPD) is a new initiative within the European Pollen Database (EPD) to establish a publicly accessible repository of modern (surface sample) pollen data. This new database will complement the EPD, which at present holds only fossil sedimentary pollen data. The EMPD is freely available online to the scientific community and currently has information on almost 5,000 pollen samples from throughout the Euro-Siberian and Mediterranean regions, contributed by over 40 individuals and research groups. Here we describe how the EMPD was constructed, the various tables and their fields, problems and errors, quality controls, and continuing efforts to improve the available data