scholarly journals Seasonal Variability of Photosynthetic Microbial Eukaryotes (<3 µm) in the Kara Sea Revealed by 18S rDNA Metabarcoding of Sediment Trap Fluxes

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2394
Author(s):  
Tatiana A. Belevich ◽  
Irina A. Milyutina ◽  
Aleksey V. Troitsky
Keyword(s):  
Water Sample ◽  
Sediment Trap ◽  
Taxonomic Composition ◽  
Kara Sea ◽  
Northwestern Part ◽  
Microbial Eukaryotes ◽  
Photosynthetic Eukaryotes ◽  
High Contribution ◽  
Order Of Magnitude

This survey is the first to explore the seasonal cycle of microbial eukaryote diversity (<3 µm) using the NGS method and a 10-month sediment trap (2018–2019). The long-term trap was deployed from September to June in the northwestern part of the Kara Sea. A water sample collected before the sediment trap was deployed and also analyzed. The taxonomic composition of microbial eukaryotes in the water sample significantly differed from sediment trap samples, characterized by a high abundance of Ciliophora reads and low abundance of Fungi while trap samples contained an order of magnitude less Ciliophora sequences and high contribution of Fungi. Photosynthetic eukaryotes (PEs) accounting for about 34% of total protists reads were assigned to five major divisions: Chlorophyta, Cryptophyta, Dinoflagellata, Haptophyta, and Ochrophyta. The domination of phototrophic algae was revealed in late autumn. Mamiellophyceae and Trebouxiophyceae were the predominant PEs in mostly all of the studied seasons. Micromonas polaris was constantly present throughout the September–June period in the PE community. The obtained results determine the seasonal dynamics of picoplankton in order to improve our understanding of their role in polar ecosystems.

scholarly journals Statistically rigorous calculations do not support common input and long-term synchronization of motor-unit firings

2014 ◽  
Vol 112 (11) ◽  
pp. 2729-2744 ◽  
Author(s):  
Carlo J. De Luca ◽  
Joshua C. Kline
Keyword(s):  
Motor Unit ◽  
Statistical Tests ◽  
Vastus Lateralis ◽  
Common Input ◽  
Data Set ◽  
Order Of Magnitude ◽  
Score Method ◽  
Surface Electromyographic Signal ◽  
Measure Synchronization

Over the past four decades, various methods have been implemented to measure synchronization of motor-unit firings. In this work, we provide evidence that prior reports of the existence of universal common inputs to all motoneurons and the presence of long-term synchronization are misleading, because they did not use sufficiently rigorous statistical tests to detect synchronization. We developed a statistically based method (SigMax) for computing synchronization and tested it with data from 17,736 motor-unit pairs containing 1,035,225 firing instances from the first dorsal interosseous and vastus lateralis muscles—a data set one order of magnitude greater than that reported in previous studies. Only firing data, obtained from surface electromyographic signal decomposition with >95% accuracy, were used in the study. The data were not subjectively selected in any manner. Because of the size of our data set and the statistical rigor inherent to SigMax, we have confidence that the synchronization values that we calculated provide an improved estimate of physiologically driven synchronization. Compared with three other commonly used techniques, ours revealed three types of discrepancies that result from failing to use sufficient statistical tests necessary to detect synchronization. 1) On average, the z-score method falsely detected synchronization at 16 separate latencies in each motor-unit pair. 2) The cumulative sum method missed one out of every four synchronization identifications found by SigMax. 3) The common input assumption method identified synchronization from 100% of motor-unit pairs studied. SigMax revealed that only 50% of motor-unit pairs actually manifested synchronization.

scholarly journals Mineralogical, numerical and analytical studies of the coupled oxidation of pyrite and coal

2003 ◽  
Vol 67 (2) ◽  
pp. 381-398 ◽  
Author(s):  
K. A. Evans ◽  
C. J. Gandy ◽  
S. A. Banwart
Keyword(s):  
Reactive Transport ◽  
Transport Model ◽  
Pyrite Oxidation ◽  
Spoil Heap ◽  
Reaction Fronts ◽  
Order Of Magnitude ◽  
Magnitude Variation ◽  
Discharge Chemistry ◽  
Analytical Expressions

Mineralogical, bulk and field leachate compositions are used to identify important processes governing the evolution of discharges from a coal spoil heap in County Durham. These processes are incorporated into a numerical one-dimensional advective-kinetic reactive transport model which reproduces field results, including gas compositions, to within an order of magnitude. Variation of input parameters allows the effects of incorrect initial assumptions on elemental profiles and discharge chemistry to be assessed. Analytical expressions for widths and speeds of kinetic reaction fronts are developed and used to predict long-term development of mineralogical distribution within the heap. Results are consistent with observations from the field site. Pyrite oxidation is expected to dominate O2 consumption in spoil heaps on the decadal timescale, although C oxidation may stabilize contaminants in effluents on the centennial scale.

Flora of technologenic landscapes of the taiga zone of the European North-East (Komi Republic)

2021 ◽  
Author(s):  
V.A. Martynenko ◽  
◽  
B.I. Gruzdev
Keyword(s):  
Vascular Plants ◽  
Komi Republic ◽  
Taxonomic Composition ◽  
Taiga Zone ◽  
North East ◽  
Annotated List ◽  
European North ◽  
Disturbed Areas ◽  
Synanthropic Flora

The results of a long-term studu of the flora of technologenichabitats of the taiga zone of the Komi Republic are summarized. An annotated list of vascular plants is presented, including 406 species from 222 genera and 52 families. For each of them, it is indicated that they belong to a life from, an element of the flora and type of area, an ecologicsl group, zonal and ecotopic affinity. Data on the taxonomic composition of vascular plants, the biomorphrological, geographical, and ecological structures of synanthropic flora, the diversity of synanthropic plant communities, and the stages of vegetation restoration in disturbed areas are presented.

Quantifying long‐term recurrence in planktonic microbial eukaryotes

2019 ◽  
Vol 28 (5) ◽  
pp. 923-935 ◽  
Author(s):  
Caterina R. Giner ◽  
Vanessa Balagué ◽  
Anders K. Krabberød ◽  
Isabel Ferrera ◽  
Albert Reñé ◽  
...  
Keyword(s):  
Microbial Eukaryotes

Paleomagnetic Analysis Of A Long-Term Sediment Trap, Kooken Cave, Huntingdon County, Pennsylvania, USA

2007 ◽  
pp. 71-81 ◽  
Author(s):  
Ira. D. Sasowsky ◽  
Rebecca A. Clotts ◽  
Bryan Crowell ◽  
Selena M. Walko ◽  
Edward J. LaRock ◽  
...  
Keyword(s):  
Sediment Trap

scholarly journals Cosmogenic burial dating of in cave-deposited alluvium: unravelling long-term incision rates and complex speleogenesis in multi-level cave systems

2020 ◽  
Author(s):  
Gilles Rixhon ◽  
Didier L. Bourlès ◽  
Régis Braucher ◽  
Alexandre Peeters ◽  
Alain Demoulin
Keyword(s):  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Fluvial Terrace ◽  
Base Level ◽  
Cave System ◽  
River Incision ◽  
Order Of Magnitude ◽  
History Of ◽  
Multi Level

&lt;p&gt;Multi-level cave systems record the history of regional river incision in abandoned alluvium-filled phreatic passages which, mimicking fluvial terrace sequences, represent former phases of fluvial base-level stability. In this respect, cosmogenic burial dating of in cave-deposited alluvium (usually via the nuclide pair &lt;sup&gt;26&lt;/sup&gt;Al/&lt;sup&gt;10&lt;/sup&gt;Be) represents a suitable method to quantify the pace of long-term river incision. Here, we present a dataset of fifteen &lt;sup&gt;26&lt;/sup&gt;Al/&lt;sup&gt;10&lt;/sup&gt;Be burial ages measured in fluvial pebbles washed into a multi-level cave system developed in Devonian limestone of the uplifted Ardenne massif (eastern Belgium). The large and well-documented Chawresse system is located along the lower Ourthe valley (i.e. the main Ardennian tributary of the Meuse river) and spans altogether an elevation difference exceeding 120 m.&lt;/p&gt;&lt;p&gt;The depleted &lt;sup&gt;26&lt;/sup&gt;Al/&lt;sup&gt;10&lt;/sup&gt;Be ratios measured in four individual caves show two main outcomes. Firstly, computed burial ages ranging from ~0.2 to 3.3 Ma allows highlighting an acceleration by almost one order of magnitude of the incision rates during the first half of the Middle Pleistocene (from ~25 to ~160 m/Ma). Secondly, according to the relative elevation above the present-day floodplain of the sampled material in the Manants cave (&lt;35 m), the four internally-consistent Early Pleistocene burial ages highlight an &amp;#8220;anomalous&amp;#8221; old speleogenesis in the framework of a gradual base-level lowering. They instead point to intra-karsting reworking of the sampled material in the topographically complex Manants cave. This in turn suggests an independent, long-lasting speleogenetic evolution of this specific cave, which differs from the &lt;em&gt;per descensum&lt;/em&gt; model of speleogenesis generally acknowledged for the regional multi-level cave systems and their abandoned phreatic galleries. In addition to its classical use for inferring long-term incision rates, cosmogenic burial dating can thus contribute to better understand specific and complex speleogenetic evolution.&lt;/p&gt;

scholarly journals Distribution of Microfossils in the Vendian Deposits of the Orsha Depression of the East European Platform, Belarus

2021 ◽  
Vol 29 (6) ◽  
pp. 627-640
Author(s):  
E. Yu. Golubkova ◽  
O. F. Kuzmenkova ◽  
E. A. Kushim ◽  
A. G. Laptsevich ◽  
S. S. Mankievič ◽  
...  
Keyword(s):  
East European Platform ◽  
Taxonomic Composition ◽  
Northwestern Part ◽  
East European ◽  
The Third ◽  
The North ◽  
Upper Vendian

Abstract— The complete sections of the Lower and Upper Vendian of the East European Platform were opened in the boreholes of Belarus. This allows us to consider this region as a stratotype area. In order to update the paleontological characteristics of the Vendian, organic-walled microfossils from the Bogushevsk-1, Bogushevsk-2 (Liozno), and Lepel-1 reference boreholes drilled in the north of the Orsha Depression were studied. The transitive assemblage I with Leiosphaeridia minutissima–Leiosphaeridia tenuissima was recognized in the Lower Vendian Liozno Formation of the Volyn Series and the Upper Vendian Kotlin Formation. The Redkino microfossil assemblages were identified at three stratigraphic levels in the Nizy, Selyava, and Chernitsa formations: assemblage II with Morania zinkovi, assemblage III with Morania zinkovi–Tynnia precambrica, and assemblage IV with Morania zinkovi–Tynnia precambrica–Striatella coriacea, respectively. The Kotlin assemblage V with Vendotaenia antiqua–Primoflagella speciosa was distinguished in the upper part of the Kotlin Formation (Bogushevsk-1 borehole). On the basis of the taxonomic composition, assemblages III and IV are correlated with the first Redkino biota of the Starorusskaya Formation; assemblage V is correlated with the third Kotlin biota of the Vasileostrovskaya Formation of the northwestern part of Russia. Our data show a high biostratigraphic potential of organic-walled microfossils, which should be used to substantiate regional stratigraphic units of the Upper Vendian in the updated stratigraphic scheme of the East European Platform.

scholarly journals POTENTIALITY OF THE BUGOJNO COAL BASIN, BOSNIA AND HERZEGOVINA

2021 ◽  
Vol 1 (24) ◽  
Author(s):  
Dževad Forčaković ◽  
Rejhana Dervišević
Keyword(s):  
Raw Material ◽  
Northwestern Part ◽  
Material Base ◽  
Coal Basin ◽  
Surface Distribution ◽  
Research Results ◽  
Geological Characteristics ◽  
Quantitative Characteristics

This paper presents research results of the Bugojno coal basin, which contains very significant, but still insufficiently explored lignite reserves. Based on the determined borders of surface distribution and the research results in the northwestern part of the Bugojno coal basin, proved are four coal layers with reserves of over one billion tons of coal. Discussed are geological characteristics of coal layers, their qualitative-quantitative characteristics, spatial potential of deposit and classification of coal layers. Considering the raw material potential and the possibility of expanding the existing raw material base, the Bugojno coal basin has particular importance for the long-term development of lignite exploitation and its use for thermal energy purposes.

Meiobenthos as indicator of gaseous hydrocarbons reservoirs existing under the seabed of the Black Sea

2021 ◽  
Author(s):  
Valentina Yanko ◽  
Anna Kravchuk ◽  
Irina Kulakova ◽  
Tatiana Kondariuk
Keyword(s):  
Black Sea ◽  
Abiotic Factors ◽  
Taxonomic Composition ◽  
The Black Sea ◽  
Northwestern Part ◽  
Hydrocarbon Gases ◽  
The Sustainable Development ◽  
Dual Analysis ◽  
Gaseous Hydrocarbons ◽  
Physical And Chemical

&lt;p&gt;This &lt;span&gt;presentation&lt;/span&gt; represents a case study that reviews research into the relationship between meiobenthos distribution and concentrations of hydrocarbon gases (HG), primarily methane, in the sediments of the northwestern part of the Black Sea, including gases released by mud volcanoes and gas seeps. Evidence forming the basis of this research comes from meiobenthos here represented by 29 species of benthic foraminifers, 7 species of ostracods, and 44 species of nematodes. The potential use of these meiobenthic organisms as indicators of gaseous hydrocarbons reservoirs existing under the seabed is evaluated according to two linked axes, namely the dual analysis of abiotic factors (physical and chemical parameters of the water column, gasmetrical, geochemical, lithological, and mineralogical properties of the sediments) and biotic characteristics (quantitative and taxonomic composition of foraminifers, nematodes, and ostracods). Studies of this kind have been directed toward developing interdisciplinary methods to improve the search for HG accumulations, especially methane, under the seabed. Development of such methods might have substantial socio-economic importance for the economy of Ukraine as well as that of other Black Sea countries, and such methods might also contribute to the sustainable development of Black Sea ecosystems.&lt;/p&gt;

Inferring rock glacier genesis and dynamics from age-layer modelling and borehole age-profile

2021 ◽  
Author(s):  
Gwendolyn J.-M. C. Leysinger Vieli ◽  
Andreas Vieli ◽  
Alessandro Cicoira
Keyword(s):  
Accumulation Rate ◽  
Bottom Layer ◽  
Rock Glacier ◽  
Depth Profiles ◽  
Talus Slope ◽  
Order Of Magnitude ◽  
Rock Glaciers ◽  
Age Profile ◽  
Modelling Approach

&lt;p&gt;The genesis of rock glaciers differs fundamentally from &amp;#8216;normal&amp;#8217; glaciers and results in much older landforms that are often reaching ages of several millennia. Recent datings of rock glacier material from boreholes indicate early Holocene ages for rock glaciers and allow the derivation of age-depth profiles at the borehole location. We use here a 2-dimensional numerical modelling approach that calculates age-layers (isochrones) within the rock glacier body and that considers the accretion, melt and flow-advection of rock glacier material. We apply this model to the case of Lazaun rock glacier (Southern &amp;#214;tztal Alps) for which a well dated profile from a borehole exists, with ages at the bottom older than 9000 years (Krainer et al. 2015). With our modelling we are able to reproduce the observed age-depth profiles well and are able to infer a long-term accumulation rate that is around 1 cm/yr which is an order of magnitude higher than a previous estimate that does not account for deformation. The modelling is consistent with the classic rock glacier genesis of material accretion in the upstream talus slope and confirms the dominance of deformation in the shear-zone at the bottom layer of the rock glacier.&lt;br&gt;We conclude that combining age-layer modelling with dated depth-profiles of rock glaciers allows for important new insights into our understanding of rock glacier evolution and dynamics.&lt;/p&gt;&lt;p&gt;REFERENCES &amp;#160;&lt;br&gt;Krainer, K., Bressan, D., Dietre, B., Haas, J., Hajdas, I., Lang, K. &amp; Tonidandel, D. (2015). A 10,300-year-old permafrost core from the active rock glacier Lazaun, southern Oetztal Alps (South Tyrol, Northern Italy). Quaternary Research, 83 , 324-335.&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

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