Neoproterozoic microfossils from the northeastern margin of the East European Platform

2009 ◽  
Vol 83 (2) ◽  
pp. 161-196 ◽  
Author(s):  
Nataliya G. Vorob'eva ◽  
Vladimir N. Sergeev ◽  
Andrew H. Knoll
Keyword(s):  
East European Platform ◽  
Sedimentary Rocks ◽  
Life Cycles ◽  
Ice Age ◽  
Ural Mountains ◽  
Resting Stages ◽  
East European ◽  
Upper Riphean ◽  
The World ◽  
Eukaryotic Organisms

The Kel'tminskaya-1 borehole, drilled along the northeastern margin of the East European Platform (EEP), reveals some 3,600 m of Neoproterozoic sedimentary rocks, mostly confined to the subsurface. The upper 1,000 m of the drilled section correlates with late Ediacaran Redkino and Kotlin successions on the EEP, whereas the lowermost 2,000 m can be related to pre-Sturtian (Upper Riphean) deposits in the Ural Mountains. In between lies the Vychegda Formation, a 600 m siliciclastic succession that has no counterpart in classic EEP stratigraphy.Vychegda microfossils can be separated into three assemblages. The upper part of the formation contains large, profusely ornamented acritarchs broadly comparable to those of the Ediacaran Complex Acanthomorph Palynoflora, including species of the generaAlicesphaeridium, Asterocapsoides, CavaspinaandTanariumconfined to Ediacaran-aged assemblages elsewhere. Diverse large acanthomorphs are known from Ediacaran strata around the world, but have not previously been recognized from the EEP, an absence attributed to a hiatus between the glacial Laplandian (>635 Ma) and Redkino (mostly <555 Ma) successions. The large acanthomorphic acritarchs record eukaryotic organisms with resting stages in their life cycles and likely include egg or diapause cysts of early animals. In contrast, the lower Vychegda assemblage, found in the basal 10 m of the succession, contains taxa typical of earlier Neoproterozoic successions. The middle assemblage contains only simple filaments and spheroidal acritarchs.The most parsimonious interpretation of Vychegda biostratigraphy is that pre-Marinoan rocks in the basal part of the formation are separated by a cryptic unconformity from early and middle Ediacaran deposits above. This interpretation is consistent with data from China and Australia, which indicate that the major paleontological transition to diverse ECAP assemblages took place within the Ediacaran Period and not in association with the preceding ice age. Vychegda acritarch assemblages thus contribute to a biostratigraphic model for the initial Ediacaran boundary.

Book Reviews

2006 ◽  
Vol 56 (4) ◽  
pp. 455-468
Author(s):  
Zoltán Ádám ◽  
László Csaba ◽  
András Bakács ◽  
Zoltán Pogátsa
Keyword(s):  
Developing Countries ◽  
Fiscal Policy ◽  
Monetary Union ◽  
Economic And Monetary Union ◽  
European Studies ◽  
Eu Accession ◽  
East European ◽  
The World ◽  
The Government

István Csillag - Péter Mihályi: Kettős kötés: A stabilizáció és a reformok 18 hónapja [Double Bandage: The 18 Months of Stabilisation and Reforms] (Budapest: Globális Tudás Alapítvány, 2006, 144 pp.) Reviewed by Zoltán Ádám; Marco Buti - Daniele Franco: Fiscal Policy in Economic and Monetary Union. Theory, Evidence and Institutions (Cheltenham/UK - Northampton/MA/USA: Edward Elgar Publishing Co., 2005, 320 pp.) Reviewed by László Csaba; Piotr Jaworski - Tomasz Mickiewicz (eds): Polish EU Accession in Comparative Perspective: Macroeconomics, Finance and the Government (School of Slavonic and East European Studies, University College of London, 2006, 171 pp.) Reviewed by András Bakács; Is FDI Based R&D Really Growing in Developing Countries? The World Investment Report 2005. Reviewed by Zoltán Pogátsa

The morphology and ultrastructure of pollen grains of Scutasporites nanuki Utting (Sashiniaceae, Coniferales) from the Permian of the East-European Platform

Palaeobotany ◽  
2012 ◽  
Vol 3 ◽  
pp. 5-11
Author(s):  
A. V. Gomankov ◽  
V. F. Tarasevich
Keyword(s):  
East European Platform ◽  
Central Body ◽  
Pollen Grains ◽  
Irregular Shape ◽  
East European ◽  
Sem And Tem

Dispersed bisaccate pollen grains of Scutasporites nanuki were studied by means of LM, SEM and TEM. Sacci ultrastructure of these pollen grains was rather peculiar. Sacci were like a thin fi lmy fringe attached to the central body near the equator. They were fi lled with sporopollenin elements of irregular shape and various dimensions with equally various cavities between them. Such an ultrastructure is called as spongy. The morphology and ultrastructure of S. nanuki is discussed in the context of the evolution of early conifers.

The quasiplatform sediments of the East European Platform

2005 ◽  
Vol 7 (5) ◽  
pp. 1-12
Author(s):  
M. A. Nagornyi ◽  
V. G. Nikolaev
Keyword(s):  
East European Platform ◽  
East European

Palaeolithic Cave Art at Creswell Crags in European Context

2007 ◽  
Keyword(s):  
Late Pleistocene ◽  
Rock Art ◽  
Ice Age ◽  
Upper Palaeolithic ◽  
Southern France ◽  
European Context ◽  
The World ◽  
Cave Art ◽  
Illustrated Book

Cave art is a subject of perennial interest among archaeologists. Until recently it was assumed that it was largely restricted to southern France and northern Iberia, although in recent years new discoveries have demonstrated that it originally had a much wider distribution. The discovery in 2003 of the UK's first examples of cave art, in two caves at Creswell Crags on the Derbyshire/Nottinghamshire border, was the most surprising illustration of this. The discoverers (the editors of the book) brought together in 2004 a number of Palaeolithic archaeologists and rock art specialists from across the world to study the Creswell art and debate its significance, and its similarities and contrasts with contemporary Late Pleistocene ("Ice Age") art on the Continent. This comprehensively illustrated book presents the Creswell art itself, the archaeology of the caves and the region, and the wider context of the Upper Palaeolithic era in Britain, as well as a number of up-to-date studies of Palaeolithic cave art in Spain, Portugal, France, and Italy which serve to contextualize the British examples.

scholarly journals Latin America in Global History: An Historiographic Overview

2017 ◽  
Vol 30 (60) ◽  
pp. 253-272 ◽  
Author(s):  
Diego Olstein
Keyword(s):  
Latin America ◽  
Sixteenth Century ◽  
New World ◽  
World History ◽  
The Other ◽  
Ice Age ◽  
Global History ◽  
The World ◽  
Last Ice Age ◽  
Great Divergence

Abstract World history can be arranged into three major regional divergences: the 'Greatest Divergence' starting at the end of the last Ice Age (ca. 15,000 years ago) and isolating the Old and the New Worlds from one another till 1500; the 'Great Divergence' bifurcating the paths of Europe and Afro-Asia since 1500; and the 'American Divergence' which divided the fortunes of New World societies from 1500 onwards. Accordingly, all world regions have confronted two divergences: one disassociating the fates of the Old and New Worlds, and the other within either the Old or the New World. Latin America is in the uneasy position that in both divergences it ended up on the 'losing side.' As a result, a contentious historiography of Latin America evolved from the very moment that it was incorporated into the wider world. Three basic attitudes toward the place of Latin America in global history have since emerged and developed: admiration for the major impact that the emergence on Latin America on the world scene imprinted on global history; hostility and disdain over Latin America since it entered the world scene; direct rejection of and head on confrontation in reaction the former. This paper examines each of these three attitudes in five periods: the 'long sixteenth century' (1492-1650); the 'age of crisis' (1650-1780); 'the long nineteenth century' (1780-1914); 'the short twentieth century' (1914-1991); and 'contemporary globalization' (1991 onwards).

Nd isotope composition of the Ediacaran and earliest Cambrian phosphorite nodules and Fe sulphide from the East European Platform

2020 ◽  
Vol 157 (12) ◽  
pp. 2081-2088
Author(s):  
Sergey B Felitsyn ◽  
Eugeny S. Bogomolov
Keyword(s):  
East European Platform ◽  
Isotope Composition ◽  
Water Reservoir ◽  
Secular Change ◽  
Early Cambrian ◽  
Iron Sulphide ◽  
Nd Isotope ◽  
East European ◽  
Moscow Syneclise ◽  
Nd Isotope Composition

AbstractAn enhanced concentration of phosphorus has been found at the stratigraphic level of the disappearance of Ediacaran taxa in two areas, the Cis-Dniester region and the Moscow syneclise, on the East European Platform (EEP). The isotope composition of neodymium was determined in Fe sulphide and phosphorite in the same beds. Measured εNd(t) values in diagenetic phosphate nodules are similar to those in iron sulphide from the same layer. During the Ediacaran − Early Cambrian, accumulation of radiogenic Nd in the epeiric basins on the EEP increased progressively from −17.9 and −19.4 in pyrite from the sequence bottom to −7.9 and −8.5 in the Early Cambrian pyrite of the central part of the EEP. The Ediacaran phosphate nodules show εNd(t) ranging from −12.9 to −15.0, while that in the Early Cambrian nodules is typically c. −9.0. These data indicate the secular change in Nd isotope composition of the water reservoir on the EEP from Ediacaran to Cambrian.

scholarly journals Dimer Interface Organization is a Main Determinant of Intermonomeric Interactions and Correlates with Evolutionary Relationships of Retroviral and Retroviral-Like Ddi1 and Ddi2 Proteases

2020 ◽  
Vol 21 (4) ◽  
pp. 1352 ◽  
Author(s):  
János András Mótyán ◽  
Márió Miczi ◽  
József Tőzsér
Keyword(s):  
Structural Characteristics ◽  
Limited Proteolysis ◽  
Structural Data ◽  
Data Bank ◽  
Life Cycles ◽  
Evolutionary Relationships ◽  
Multiple Sequence ◽  
Dimer Interface ◽  
Viral Proteases ◽  
Eukaryotic Organisms

The life cycles of retroviruses rely on the limited proteolysis catalyzed by the viral protease. Numerous eukaryotic organisms also express endogenously such proteases, which originate from retrotransposons or retroviruses, including DNA damage-inducible 1 and 2 (Ddi1 and Ddi2, respectively) proteins. In this study, we performed a comparative analysis based on the structural data currently available in Protein Data Bank (PDB) and Structural summaries of PDB entries (PDBsum) databases, with a special emphasis on the regions involved in dimerization of retroviral and retroviral-like Ddi proteases. In addition to Ddi1 and Ddi2, at least one member of all seven genera of the Retroviridae family was included in this comparison. We found that the studied retroviral and non-viral proteases show differences in the mode of dimerization and density of intermonomeric contacts, and distribution of the structural characteristics is in agreement with their evolutionary relationships. Multiple sequence and structure alignments revealed that the interactions between the subunits depend mainly on the overall organization of the dimer interface. We think that better understanding of the general and specific features of proteases may support the characterization of retroviral-like proteases.

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