The diagenesis of the Bryansk paleosol (MIS 3) in a suffusion micro-depression at the center of the Russian Upland

2020 ◽  
Author(s):  
Svetlana Sycheva ◽  
Olga Khokhlova
Keyword(s):  
Chemical Properties ◽  
Basic Research ◽  
Illuvial Horizon ◽  
Plant Residues ◽  
Clay Material ◽  
Final Phase ◽  
The Holocene ◽  
Fine Material ◽  
Mis 3 ◽  
Central Russian Upland

<p>A catena of the Holocene soils and interstadial Bryansk paleosol has been studied within a small closed depression in the Kazatskaya Steppe on the Central Russian Upland. This depression is located on the territory of the Central Chernozem Biospheric Reserve named after V.V. Alekhin, Kursk oblast, Russia and presumably originated from suffosion processes. The main objective of the work is to find out how the Bryansk paleosol (final phase of MIS 3) changes under the influence of not only the cryogenesis of the Valdai glaciation maximum (MIS 2), but also Holocene soil formation (MIS 1) under different conditions of the modern microrelief within the studied catena. We studied the macro- and micromorphological characteristics, certain physical and chemical properties of the Bryansk paleosol on one hand and those of the superimposed Holocene soil on another, taking into consideration various conditions of the present-day microrelief. The studied catena is a typical component of the landscape and soil cover structure for watersheds of the Central Russian Upland. On the micro-elevation rising 80 cm above the micro-depression bottom, theHaplic Chernozems are developed, on the slope – the Luvic Chernozems, and at the bottom – theStagnic Chernozems. The change of the "normal" profile of paleosol of warm interstadial in final phase of MIS 3 started already in the last stages of its formation. The Bryansk soil is heavily deformed by cryogenic processes during the Valday glaciation maximum (the Vladimir cryogenic horizon, MIS 2). The secondary diagenesis of the Bryansk paleosol is related to the Holocene soil-forming processes. The Holocene soils are superimposed on the Middle Valday Bryansk paleosol, transforming it in different ways in different sectors of catena. On micro-elevation the Holocene diagenesis is minimal and consists in fragmentation by mesofauna, additional penetration of carbonates in the upper horizon of the paleosol. The micromorphological analysis showed that the fragmentation of soil mass by mezofauna is very significant, humus is abundant in the form of brown spots (organo-mineral complexes), and calcite is completely immersed into the clay fine material. The largest in size but rare grains of sparite have an unusual shape and probably biogenic origin. At the bottom of the micro-depression the Bryansk paleosol is the most transformed, and the entire profile of the Bryansk soil turned into illuvial horizon of the Holocene meadow-chernozem soil. At the micro-level of observation the clay fine material of the Bryansk soil is strongly consolidated (close c/f related distribution), has signs of anisotropy: circular, grano- and crosstriated b-fabric, the mineral grains are almost invisible and have the dimension of fine dust, very thin Fe- clay coatings in the pores, Fe spots are scattered over the fine clay material, and very characteristic of the presence of many black and sometimes transparent with a black border cube-shaped minerals (whewellite, weddellite?) which fill plant residues in the pores. This work was supported by the Russian Foundation for Basic Research; project N 19-29-05024 mk.</p>

scholarly journals Serial profiling of cell-free DNA and nucleosome histone modifications in cell cultures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vida Ungerer ◽  
Abel J. Bronkhorst ◽  
Priscilla Van den Ackerveken ◽  
Marielle Herzog ◽  
Stefan Holdenrieder
Keyword(s):  
Cancer Cells ◽  
Histone Modifications ◽  
Chemical Properties ◽  
Basic Research ◽  
Live Cells ◽  
Cycle Phase ◽  
Cell Free Dna ◽  
Free Dna ◽  
High Resolution Analysis ◽  
Active Release

AbstractRecent advances in basic research have unveiled several strategies for improving the sensitivity and specificity of cell-free DNA (cfDNA) based assays, which is a prerequisite for broadening its clinical use. Included among these strategies is leveraging knowledge of both the biogenesis and physico-chemical properties of cfDNA towards the identification of better disease-defining features and optimization of methods. While good progress has been made on this front, much of cfDNA biology remains uncharted. Here, we correlated serial measurements of cfDNA size, concentration and nucleosome histone modifications with various cellular parameters, including cell growth rate, viability, apoptosis, necrosis, and cell cycle phase in three different cell lines. Collectively, the picture emerged that temporal changes in cfDNA levels are rather irregular and not the result of constitutive release from live cells. Instead, changes in cfDNA levels correlated with intermittent cell death events, wherein apoptosis contributed more to cfDNA release in non-cancer cells and necrosis more in cancer cells. Interestingly, the presence of a ~ 3 kbp cfDNA population, which is often deemed to originate from accidental cell lysis or active release, was found to originate from necrosis. High-resolution analysis of this cfDNA population revealed an underlying DNA laddering pattern consisting of several oligo-nucleosomes, identical to those generated by apoptosis. This suggests that necrosis may contribute significantly to the pool of mono-nucleosomal cfDNA fragments that are generally interrogated for cancer mutational profiling. Furthermore, since active steps are often taken to exclude longer oligo-nucleosomes from clinical biospecimens and subsequent assays this raises the question of whether important pathological information is lost.

scholarly journals The Ice-Rich Permafrost Sequences as a Paleoenvironmental Archive for the Kara Sea Region (Western Arctic)

2021 ◽  
Vol 9 ◽  
Author(s):  
I. D. Streletskaya ◽  
A. A. Pismeniuk ◽  
A. A. Vasiliev ◽  
E. A. Gusev ◽  
G. E. Oblogov ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Marine Sediments ◽  
Isotope Composition ◽  
Kara Sea ◽  
Coastal Sediments ◽  
Organic Carbon Content ◽  
Ground Ice ◽  
Geochemical Composition ◽  
The Holocene ◽  
Mis 3

The Kara Sea coast and part of the shelf are characterized by wide presence of the ice-rich permafrost sequences containing massive tabular ground ice (MTGI) and ice wedges (IW). The investigations of distribution, morphology and isotopic composition of MTGI and IW allows paleoenvironmental reconstructions for Late Pleistocene and Holocene period in the Kara Sea Region. This work summarizes result of long-term research of ice-rich permafrost at eight key sites located in the Yamal, Gydan, Taimyr Peninsulas, and Sibiryakov Island. We identified several types of ground ice in the coastal sediments and summarized data on their isotopic and geochemical composition, and methane content. We summarized the available data on particle size distribution, ice chemical composition, including organic carbon content, and age of the enclosing ice sediments. The results show that Quaternary sediments of the region accumulated during MIS 5 – MIS 1 and generally consisted of two main stratigraphic parts. Ice-rich polygenetic continental sediments with syngenetic and epigenetic IW represent the upper part of geological sections (10–15 m). The IW formed in two stages: in the Late Pleistocene (MIS 3 – MIS 2) and in the Holocene cold periods. Oxygen isotope composition of IW formed during MIS 3 – MIS 2 is on average 6‰ lower than that of the Holocene IW. The saline clay with rare sand layers of the lower part of geological sections, formed in marine and shallow shelf anaerobic conditions. MTGI present in the lower part of the sections. The MTGI formed under epigenetic freezing of marine sediments immediately after sea regression and syngenetic freezing of marine sediments in the tidal zone and in the conditions of shallow sea.

scholarly journals Changes in some chemical properties of saline-sodic soils over time as affected by organic residues: An incubation study

2020 ◽  
Vol 53 (1) ◽  
pp. 1
Author(s):  
Mohsen Jalali ◽  
Maryam Saeedi Lotf ◽  
Faranak Ranjbar
Keyword(s):  
Crop Production ◽  
Positive Impact ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
Limiting Factors ◽  
Plant Residues ◽  
Organic Residues ◽  
Sodic Soils ◽  
Treated Soil ◽  
Incubation Study

<p>Salinization and sodification of agricultural lands in arid and semi-arid regions of the world are two limiting factors in the crop production. This study was conducted to evaluate the effect of readily available agricultural residues on changing some chemical properties of saline-sodic soils. Wheat, potato, sunflower, and canola residues were separately added into three saline-sodic soils at a rate of 2% by weight and thoroughly mixed with soils. Control and treated soils were incubated for 168 days at a constant moisture and temperature. The pH, electrical conductivity (EC), soluble cations, available nitrate (NO3-) and phosphorous (P), cation exchange capacity (CEC), and exchangeable sodium percentage (ESP) were measured during the incubation. The EC increased in the response to the incorporation of plant residues, whereas the pH was reduced. The application of organic components in soils increased CEC and decreased ESP. The results showed that the maximum reduction in ESP was observed in the potato treatment because of the highest Ca2+ concentration. The average reduction in ESP of treated soil samples at the end of incubation followed this order: 16.1% (potato residue-treated soil) &gt;12.7% (canola residue-treated soil) &gt;11.1% (wheat residue-treated soil) &gt;9.6% (sunflwer residue-treated soil). The potato residue was the most effective amendment in changing the chemical properties of saline-sodic soils in comparison with other organic residues. The results indicated that the application of organic residues had a positive impact on reducing the soil sodicity and improving the soil fertility depending on their chemical composition.</p>

scholarly journals Protein Adsorption: A Feasible Method for Nanoparticle Functionalization?

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1991 ◽  
Author(s):  
Roberta Cagliani ◽  
Francesca Gatto ◽  
Giuseppe Bardi
Keyword(s):  
Protein Adsorption ◽  
Biological Fluids ◽  
Chemical Properties ◽  
Surface Protein ◽  
Basic Research ◽  
Small Peptides ◽  
Small Proteins ◽  
Corona Formation ◽  
Potential Applications ◽  
Or Gene

Nanomaterials are now well-established components of many sectors of science and technology. Their sizes, structures, and chemical properties allow for the exploration of a vast range of potential applications and novel approaches in basic research. Biomedical applications, such as drug or gene delivery, often require the release of nanoparticles into the bloodstream, which is populated by blood cells and a plethora of small peptides, proteins, sugars, lipids, and complexes of all these molecules. Generally, in biological fluids, a nanoparticle’s surface is covered by different biomolecules, which regulate the interactions of nanoparticles with tissues and, eventually, their fate. The adsorption of molecules onto the nanomaterial is described as “corona” formation. Every blood particulate component can contribute to the creation of the corona, although small proteins represent the majority of the adsorbed chemical moieties. The precise rules of surface-protein adsorption remain unknown, although the surface charge and topography of the nanoparticle seem to discriminate the different coronas. We will describe examples of adsorption of specific biomolecules onto nanoparticles as one of the methods for natural surface functionalization, and highlight advantages and limitations. Our critical review of these topics may help to design appropriate nanomaterials for specific drug delivery.

Soil record of the Holocene paleofires at the north of European Russia

2020 ◽  
Author(s):  
Nikita Mergelov ◽  
Dmitry Petrov ◽  
Andrey Dolgikh ◽  
Elya Zazovskaya
Keyword(s):  
Kola Peninsula ◽  
Forest Fires ◽  
Soil Formation ◽  
Basic Research ◽  
Isotope Ratio Mass Spectrometry ◽  
Local Scale ◽  
14C Dating ◽  
The Holocene ◽  
Arkhangelsk Region ◽  
The North

&lt;p&gt;Soils and sediments serve as complementary sources of detailed information on paleofires in various ecosystems. Despite the abundance of charcoal material entrapped in soils they remain relatively less studied pyrogenic archives in comparison to the sedimentary paleofire records (e.g. lacustrine and peat deposits), and that is especially the case for the most territory of Russia. We report here on the numerous soil archives of the Holocene forest fires at the Kola Peninsula (66.347&amp;#176;N, 37.948&amp;#176;E) and the north of Arkhangelsk region (64.747&amp;#176;N, 43.387&amp;#176;E) in Russia. Series of buried Podzols (up to ten successive profiles) separated by the distinct charcoal layers were revealed in specific geomorphological traps like the thermokarst depressions inherited from the early stages of moraine sediments formation (Kola Peninsula), as well as in active and paleokarst sinkholes in carbonate and sulfate rocks (Arkhangelsk region). The maximum temporal depth of archives was estimated as 10261&amp;#177;40 cal yr BP for the key site in Arkhangelsk region, with up to 12 major pyrogenic events recorded at the local scale. Soil formation at the inter-pyrogenic stages maintained a uniform direction for at least 10 thousand years and profiles of Podzols were regularly replicated at all the key sites. We employ here a combination of soil morphological hierarchical analysis, study of geomorphological processes leading to the burial of pyrogenic carbon, 14C dating of charcoal and TOC derived from the soil organic matter, carbon and nitrogen isotope ratio mass spectrometry and anthracomass concentrations analysis to extract a set of paleoenvironmental information from these soil archives. The study of complementary pyrogenic archives in the three-component system of the karst landscape (including bottom and slopes of the funnels, as well as the flat elevated areas between them) helped to mitigate overestimation or underestimation of the anthracomass concentration and allowed to acquire a detailed dataset on paleopyrogenic events at the local scale. This study is supported by the Russian Foundation for Basic Research, Project No. 19-29-05238.&lt;/p&gt;

scholarly journals Changes of Vegetation and Climate in the North-West of the Central Russian Upland in the Holocene

2016 ◽  
pp. 103-114 ◽  
Author(s):  
E. Yu. Novenko ◽  
A. N. Tsyganov ◽  
E. M. Volkova ◽  
K. V. Babeshko ◽  
N. V. Lavrent’ev ◽  
...  
Keyword(s):  
The Holocene ◽  
North West ◽  
The North ◽  
Central Russian Upland ◽  
Vegetation And Climate

The impact of pine self-afforestation on podzolization process in semi-natural grassland areas of Volyn Polissya (Ukraine)

2021 ◽  
Vol 15 (2) ◽  
pp. 47-62
Author(s):  
V. Kozlovskyy ◽  
◽  
N. Romanyuk ◽  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Chemical Properties ◽  
Base Cation ◽  
Illuvial Horizon ◽  
Short Period ◽  
Diagnostic Horizons ◽  
The Impact ◽  
Natural Grassland

Background. Several theories have been proposed to explain the podzolization process. Currently, the role of organic matter in both weathering and immobilization in the illuvial horizon is clearly stated. The origin of soil organic matter and, accordingly, the various mechanisms of its influence on the soil material, create the basis of these theories. We assume that in the base-poor sandy soils under rich herbaceous vegetation with a well developed sod layer, the process of podzolization may also depend on CO2 soil formation agent . Materials and Methods. Four localities along a Pinus sylvestris L. self-afforestation chronosequence with pine stands of 10, 20, 40 yrs and an adjacent semi-natural grassland area were investigated in order to determine the patterns of podzolization process on sandy glacial till deposits. Soil pH, exchangeable base, soil cation exchange capacity, total content of soil organic carbon, amorphous Fe, Si and Al and total contents of Al, Fe, Mn, Zn, Cd, Pb, Cu, Co, Ni, Na, K were determined. Statistical analysis of the results was performed using LibreOffice for Linux. Results. During the pine succession, a previously well differentiated into horizons podzolic soil under the grassland vegetation community gradually degrades. Previously well-defined albic and spodic diagnostic horizons disappear, the soil profile becomes more acidic, the soil organic carbon, the base cation content and the base cation saturation decrease, the leaching rate of aluminium and iron increases. Secondary podzolization features in the soil profiles were detected 40 years after the onset of afforestation. The podzolization has not been intensive enough to develop fully fledged albic and spodic diagnostic horizons over such a short period. Conclusions. Based on the obtained soil morphological, physical and chemical properties, three most important agents of podzolization are proposed as principal for the studied area. The main gent under pine forest is fulvic acids that are produced during coniferous litter decomposition. Low molecular weight organic acids and carbon dioxide produced to the rhizosphere by roots and a root associated microbiota are mainly involved in the podzolization process under the grassland ecosystem.

Interrelations of the Bryansk paleosol (end of MIS 3) with the Holocene surface soils in micro-depressions of the central forest-steppe within the Russian Upland

CATENA ◽  
2019 ◽  
Vol 172 ◽  
pp. 619-633 ◽  
Author(s):  
Svetlana Sycheva ◽  
Olga Khokhlova ◽  
Polina Pushkina ◽  
Pavel Ukrainsky
Keyword(s):  
Forest Steppe ◽  
Surface Soils ◽  
The Holocene ◽  
Mis 3

scholarly journals Dating the Siple Dome (Antarctica) ice core by manual and computer interpretation of annual layering

2004 ◽  
Vol 50 (170) ◽  
pp. 453-461 ◽  
Author(s):  
Kendrick C. Taylor ◽  
Richard B. Alley ◽  
Debra A. Meese ◽  
Matthew K. Spencer ◽  
Ed J. Brook ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Sheet ◽  
Chemical Properties ◽  
Greenland Ice Sheet ◽  
Atmospheric Methane ◽  
Volcanic Stratigraphy ◽  
The Holocene ◽  
The Core ◽  
Siple Dome ◽  
And Chemical Properties

AbstractThe Holocene portion of the Siple Dome (Antarctica) ice core was dated by interpreting the electrical, visual and chemical properties of the core. The data were interpreted manually and with a computer algorithm. The algorithm interpretation was adjusted to be consistent with atmospheric methane stratigraphic ties to the GISP2 (Greenland Ice Sheet Project 2) ice core, 10Be stratigraphic ties to the dendrochronology 14 C record and the dated volcanic stratigraphy. The algorithm interpretation is more consistent and better quantified than the tedious and subjective manual interpretation.

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