Natural-climatic and anthropogenic factors determining the self-purification capacity of shallow-water marine ecosystems in relation to reduced nitrogen forms

2021 ◽  
Author(s):  
E. E. Sovga ◽  
I. V. Mezentseva ◽  
T. V. Khmara ◽  
◽  
◽  
...  
Keyword(s):  
Current System ◽  
The Self ◽  
Anthropogenic Factors ◽  
Sediment Layer ◽  
Nitrogen Forms ◽  
In Situ Data ◽  
Sevastopol Bay ◽  
Reduced Nitrogen ◽  
Assimilation Capacity ◽  
Reduced Forms

The paper considers natural-climatic and anthropogenic factors that determine differences in the self-purification capacity of the Sevastopol Bay ecosystems (its western, central, eastern parts and the Yuzhnaya Bay) in relation to the reduced nitrogen forms (ammonium and nitrites) by calculating the assimilation capacity. The authors took into account the intensity of the input sources of the studied forms of nitrogen, the rate of excretion from the ecosystem, the dynamic situation in the studied water areas and in the entire bay as well as the location of recreational facilities. For the first time, the factors were assessed that provide additional input of reduced forms of nitrogen associated with hypoxia during summer water stratification in local deepened areas in the upper bottom sediment layer, taking into account their particle size distribution. Further, the authors considered accumulation of organic matter and its destruction due to oxidized nitrogen forms and formation of reduced forms thereof. The currents in the central and southern parts of the Sevastopol Bay were calculated using a hydrodynamic model. The calculation results correspond to the current system in the mentioned water areas of the bay according to in situ data at different wind situations in the region. According to the calculations, it is possible that under certain hydrometeorological situations additional amount of ammonium and nitrites would flow from the Yuzhnaya Bay into the central part of the Sevastopol Bay.

SELF-PURIFICATION OF SEA COASTAL WATER AREAS UNDER CLIMATIC AND ANTHROPOGENIC CHANGE

2017 ◽  
Author(s):  
Irina Mesenzeva ◽  
Irina Mesenzeva ◽  
Elena Sovga ◽  
Elena Sovga ◽  
Tatyana Khmara ◽  
...  
Keyword(s):  
Anthropogenic Impact ◽  
Water Exchange ◽  
Water Area ◽  
Clean Water ◽  
Ecological State ◽  
Anthropogenic Change ◽  
Run Off ◽  
Open Sea ◽  
Sevastopol Bay ◽  
Assimilation Capacity

The ability of a bay and gulf ecosystems to self-purification was estimated and the current ecological state of the Sevastopol Bay in whole and the separated parts of the bay was given as an example. A zoning by type of anthropogenic impact subject to the water exchange with the open sea and an influence of the Chernaya River run-off were taken into account. A comparative analysis of assimilation capacity of the most environmentally disadvantaged part of the Sevastopol Bay (the Southern Bay) and the clean water area, bordering on the open sea, was carried out. The hydrodynamic regime of the Sevastopol Bay was described using numerical modelling. The prospect, opportunity and examples of the methodology for assessing the assimilation capacity of marine ecosystems are demonstrated.

SELF-PURIFICATION OF SEA COASTAL WATER AREAS UNDER CLIMATIC AND ANTHROPOGENIC CHANGE

2017 ◽  
Author(s):  
Irina Mesenzeva ◽  
Irina Mesenzeva ◽  
Elena Sovga ◽  
Elena Sovga ◽  
Tatyana Khmara ◽  
...  
Keyword(s):  
Anthropogenic Impact ◽  
Water Exchange ◽  
Water Area ◽  
Clean Water ◽  
Ecological State ◽  
Anthropogenic Change ◽  
Run Off ◽  
Open Sea ◽  
Sevastopol Bay ◽  
Assimilation Capacity

The ability of a bay and gulf ecosystems to self-purification was estimated and the current ecological state of the Sevastopol Bay in whole and the separated parts of the bay was given as an example. A zoning by type of anthropogenic impact subject to the water exchange with the open sea and an influence of the Chernaya River run-off were taken into account. A comparative analysis of assimilation capacity of the most environmentally disadvantaged part of the Sevastopol Bay (the Southern Bay) and the clean water area, bordering on the open sea, was carried out. The hydrodynamic regime of the Sevastopol Bay was described using numerical modelling. The prospect, opportunity and examples of the methodology for assessing the assimilation capacity of marine ecosystems are demonstrated.

The MLT distribution and detailed structure of ring current:  MMS observations

2021 ◽  
Author(s):  
Xin Tan ◽  
Malcolm Dunlop ◽  
Xiangcheng Dong ◽  
Yanyan Yang ◽  
Christopher Russell
Keyword(s):  
Current Density ◽  
Large Scale ◽  
Ring Current ◽  
Current System ◽  
Radial Profile ◽  
Three Dimensional ◽  
Current Density Distribution ◽  
Magnetic Storms ◽  
In Situ Data

<p>The ring current is an important part of the large-scale magnetosphere-ionosphere current system; mainly concentrated in the equatorial plane, between 2-7 R<sub>E</sub>, and strongly ordered between ± 30 ° latitude. The morphology of ring current directly affects the geomagnetic field at low to middle latitudes. Rapid changes in ring current densities can occur during magnetic storms/sub-storms. Traditionally, the Dst index is used to characterize the intensity of magnetic storms and to reflect the variation of ring current intensity, but this index does not reflect the MLT distribution of ring current. In fact, the ring current has significant variations with MLT, depending on geomagnetic activity, due to the influence of multiple factors; such as, the partial ring current, region 1/region 2 field-aligned currents, the magnetopause current and sub-storm cycle (magnetotail current). The form of the ring current has been inferred from the three-dimensional distribution of ion differential fluxes from neutral atom imaging; however, this technique can not directly obtain the current density distribution (as can be obtained using multi-spacecraft in situ data). Previous in situ estimates of current density have used: Cluster, THEMIS and other spacecraft groups to study the distribution of the ring current for limited ranges of either radial profile, or MLT and MLAT variations. Here, we report on an extension to these studies using FGM data from MMS obtained during the period September 1, 2015 to December 31, 2016, when the MMS orbit and configuration provided good coverage. We employ the curlometer method to calculate the current density, statistically, to analysis the MLT distribution according to different geomagnetic conditions. Our results show the clear asymmetry of the ring current and its different characteristics under different geomagnetic conditions.</p>

Comparison of Assimilative Capacity and Trophic Index for Various Parts of the Sevastopol Bay Water Area

2020 ◽  
Author(s):  
E. E. Sovga ◽  
I. V. Mezentseva ◽  
K. A. Slepchuk ◽  
◽  
◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Data Bank ◽  
Water Area ◽  
Load Level ◽  
Assimilative Capacity ◽  
In Situ Data ◽  
Trophic Index ◽  
Water Ecosystem ◽  
Sevastopol Bay ◽  
Different Parts

The ecological state of the marine shallow water ecosystem (the case of the Sevastopol Bay) is analyzed by the ratio of assimilative capacity and E-TRIX index depending on the anthropogenic load level for the whole bay ecosystem. As part of analysis, the eastern, central, western parts of the bay were distinguished as well as the Yuzhnaya Bay (southern part). Calculations of the assimilative capacity and E-TRIX index for ecosystems of different parts of the Sevastopol Bay were performed using the in situ data of inorganic nitrogen for the period 1998–2012 obtained from the MHI RAS oceanographic data bank. The paper compares values of ecosystem assimilative capacity calculated for inorganic nitrogen as a prevailing pollutant in municipal and storm wastewaters and E-TRIX trophic index of the sea ecosystem, with the technogenic load and biological process seasonality (warm and cold periods) of nutrient income taken into account. This allowed to properly distinguish water areas, which are most vulnerable in terms of formation of negative ecological events, up to disasters. According to the obtained data, such an area is that of the Yuzhnaya Bay. The second vulnerable water area is the eastern apex part of the Sevastopol bay exposed to the Chernaya River discharge. As the results showed, the situation worsens during winter and spring freshets due to increase in content of inorganic nitrogen forms in the Chernaya River runoff. The ecosystem of the western bay part adjoining the open sea is the safest in terms of nitrate nitrogen assimilative capacity, whereas the central part ecosystem appears to be the cleanest in terms of E-TRIX. The ecosystem most exposed to ecological risks in terms of both indices (assimilative capacity and E-TRIX) is that of the Yuzhnaya Bay (the southern part of the Sevastopol Bay). The observed imbalance of distribution of the calculated trophic index E-TRIX and assimilative capacity in different parts of the Sevastopol Bay is due to various nature of these quantities. The assimilative capacity of an ecosystem is defined by physical, chemical and biological processes given a dynamic removal of pollutants from the ecosystem, whereas E-TRIX is determined, in general, by seasonal variability of nutrient income into the ecosystem.

scholarly journals Theoretical Study on Self-Organization of Vegetation Patterns Triggered by Water Resource in Deposited Sediment Layer

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Tousheng Huang ◽  
Huayong Zhang ◽  
Zhao Liu ◽  
Ge Pan ◽  
Xiumin Zhang ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Water Resource ◽  
Theoretical Study ◽  
Turing Instability ◽  
The Self ◽  
Self Organization ◽  
Vegetation Patterns ◽  
Sediment Layer ◽  
Spatiotemporal Model ◽  
Parameter Values

This research focuses on the self-organization of vegetation patterns on severely degraded eroding lands, triggered by water resource in the deposited sediment layer on which the vegetation patterns are formed. A nonlinear spatiotemporal model is developed with the consideration of the interactions between vegetation biomass and water resource stored in the sediment layer. With employment of the model, the conditions for pattern formation of the considered ecological system are determined via Turing instability analysis. Numerical simulations of the research demonstrate the formation of banded, labyrinth, and gapped vegetation patterns, with the parameter values taken from the literature. The characteristics of the vegetation patterns are analyzed. Comparing the characteristics of the vegetation patterns of this research with that available in literature, great similarity of pattern formation is shown. The results obtained provide a theoretical comprehension on natural vegetation restoration of severely degraded eroding lands.

scholarly journals Determination of the Physicochemical and Microbiological Index of the River Chakvistskali

2021 ◽  
Author(s):  
Nino Lomtatidze ◽  
Marine Gvianidze
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Environmental Impact ◽  
The Self ◽  
Water Bodies ◽  
Anthropogenic Load ◽  
Anthropogenic Factors ◽  
Anthropogenic Eutrophication ◽  
Water Ecosystem

The growing impact of the anthropogenic factors on the environment has intensified the importance of protecting the water ecosystem. The degrading of water resources is a frequent result of the anthropogenic eutrophication resulting in imbalance of substance levels and deterioration of sanitation and recreational condition of water. The environmental impact of contaminants is manifested at the level of organisms, populations, biocenosis, and ecosystems. In the context of the increased anthropogenic load, the growing contamination of water bodies impairs the self-cleansing capacity of water, causes eutrophication and reduces water quality.

Problem behavior in autism spectrum disorders: A paradigmatic self-organized perspective of network structures

2019 ◽  
Vol 42 ◽  
Author(s):  
Lucio Tonello ◽  
Luca Giacobbi ◽  
Alberto Pettenon ◽  
Alessandro Scuotto ◽  
Massimo Cocchi ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Problem Behaviors ◽  
Autism Spectrum ◽  
The Self ◽  
Network Structures ◽  
Self Organized ◽  
Critical Equilibrium ◽  
Self Organized Criticality ◽  
Acute Agitation ◽  
Spectrum Disorders

AbstractAutism spectrum disorder (ASD) subjects can present temporary behaviors of acute agitation and aggressiveness, named problem behaviors. They have been shown to be consistent with the self-organized criticality (SOC), a model wherein occasionally occurring “catastrophic events” are necessary in order to maintain a self-organized “critical equilibrium.” The SOC can represent the psychopathology network structures and additionally suggests that they can be considered as self-organized systems.

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

Interrelationship of the cellular distribution and secretion of regular structure (RS) protein in Bacillus licheniformis nm 105

1992 ◽  
Vol 50 (1) ◽  
pp. 712-713
Author(s):  
Xiaorong Zhu ◽  
Richard McVeigh ◽  
Bijan K. Ghosh
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Licheniformis ◽  
Self Assembly ◽  
Gel Electrophoresis ◽  
Culture Supernatant ◽  
Regular Structure ◽  
The Self ◽  
Cellular Distribution ◽  
Structural Protein ◽  
Laboratory Cultures

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.

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