scholarly journals Spatiotemporal distribution of planktonic ciliates in the Kuybyshev water reservoir in the area of Klimovskaya narrowing

2021 ◽  
pp. 146-162
Author(s):  
S. V. Bykova ◽  
V. A. Andreeva
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Water Reservoir ◽  
Regulated River ◽  
Individual Species ◽  
Hydroelectric Power Station ◽  
Kuibyshev Reservoir ◽  
Free Living ◽  
Planktonic Ciliates ◽  
Wide Range

The paper attempts to link changes in quantitative characteristics of the community of free-living planktonic ciliates and the nature of their vertical distribution with the operation mode of the hydroelectric power station in the reservoir. Low values of the abundance (8–1,560 thousand cells / m3) and biomass (0.1–66.9 mg / m3) of ciliates in the water column, and a fairly wide range of their variation in the reservoir are probably due to the oscillatory nature of the hydrological regime in the regulated river conditions. The vertical distribution of free-living planktonic ciliates of the near-dam section of the Kuibyshev reservoir was studied at all times of the day on all days of the week. The species were distributed throughout the water column to the bottom with some preference for the surface (0–2 m) and medium (4–10 m) layers. There was no clear attachment of individual species to certain layers in the conditions of homothermy. The preference for certain horizons is due to some biological characteristics of the species (for example, peritriches on the coenobia of algae in the surface layers), departure from “blooming spots”, etc. No data in favor of vertical migrations or “turbulent transport” has yet been revealed. The influence of the weekly regime of regulation of the Zhigulevskaya HPS, in which at the end of the working week, the fluctuation amplitude of many hydrological parameters probably decreases, is manifested in an increase in the abundance and biomass of planktonic ciliates at this time.The nature of the daily change in the average ciliates abundance in the water column was the same for a variant of the community in working days and was in antiphase with the change in the community abundance on weekends, namely: the maximum number on working days and on weekends was recorded in the evening (20.00) and in the daytime (14.00), respectively.

scholarly journals The simulation model for a flood management by flood control facilities

2018 ◽  
Vol 245 ◽  
pp. 15002 ◽  
Author(s):  
Roman Davydov ◽  
Valery Antonov ◽  
Dmitry Molodtsov ◽  
Alexey Cheremisin ◽  
Vadim Korablev
Keyword(s):  
Mathematical Models ◽  
Flood Control ◽  
Flood Management ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Operating Characteristics ◽  
Hydro Power ◽  
Operation Modes ◽  
Wide Range ◽  
Environmental Requirements

The rapid spread of storm floods over large areas requires flood management throughout the river basin by the creation an innovative system of flood control facilities of various functional purposes distributed in the area. The central part of the system is the hydro system with hydro power plant. In addition, the flood control facilities on the side tributaries with self-regulating reservoir are included in the system. To assess the effect of controlling extreme water discharges by flood control facilities, it is necessary to develop special mathematical models reflecting the specifics of their operation. Unified mathematical models of the operation modes of a hydro complex with hydroelectric power station and flood control facility are created. They are implemented in a computer program that provides the ability to determine the main parameters and operating characteristics of hydro systems when performing multivariate calculations in a wide range of initial data. This makes possible specifying the parameters and operation modes of each hydro system with the current economic and environmental requirements, to assess the energy-economic and environmental consequences in the operation of the system of flood control facilities distributed in the area. The article analyses the results of the extreme water discharge’s regulation by the hydro system on the main river and flood control facilities on the side tributaries, considering environmental requirements.

UV radiation effects on the embryos of anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki) off central Chile

2016 ◽  
Vol 67 (2) ◽  
pp. 195 ◽  
Author(s):  
P. Vásquez ◽  
A. Llanos-Rivera ◽  
L. R. Castro ◽  
C. Fernandez
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Radiation Effects ◽  
Hatching Success ◽  
Sublethal Effects ◽  
Ultraviolet B ◽  
Uvb Radiation ◽  
Central Chile ◽  
Fish Embryos ◽  
Engraulis Ringens

It has been proposed that current levels of ultraviolet B (UVB) radiation could cause lethal or sublethal effects on fish embryos located in the upper layers of the water column. Observed levels of UVB off central Chile (36°S, 73°W) indicate that planktonic fish embryos could be exposed to harmful UVB radiation. From July 2011 to January 2012 embryos from anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki) were used to test experimentally whether the UVB levels in central Chile produce lethal or sublethal effects in epipelagic fish embryos. Simultaneously, whether the embryos might be exposed to harmful UVB levels in the field was investigated. Our experimental results show that UVB may cause a decrease in hatching success, changes in buoyancy and embryonic malformations. These results, along with the observed vertical distribution of embryos and UVB radiation levels in the field during late spring suggest that lethal and sublethal effects may be occurring in the embryos of both species.

Diel vertical distribution of early marine phase juvenile pink salmon (Oncorhynchus gorbuscha) and behaviour when exposed to salmon louse (Lepeophtheirus salmonis)

2011 ◽  
Vol 89 (9) ◽  
pp. 796-807 ◽  
Author(s):  
S. Tang ◽  
A.G. Lewis ◽  
M. Sackville ◽  
L. Nendick ◽  
C. DiBacco ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Pink Salmon ◽  
Distribution Patterns ◽  
Oncorhynchus Gorbuscha ◽  
Lepeophtheirus Salmonis ◽  
Night Time ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Louse ◽  
Seawater Acclimation

We observed diel vertical migration patterns in juvenile pink salmon ( Oncorhynchus gorbuscha (Walbaum, 1792)) and tested the hypothesis that fish behaviour is altered by exposure to sea lice copepodids. Experiments involved replicated field deployments of a large (9 m) plankton column, which provided a vertical distribution enclosure under natural light and salinity conditions. Diel vertical distributions of juvenile pink salmon were observed during the first 3 weeks of seawater acclimation in both the presence and the absence of the ectoparasitic salmon louse ( Lepeophtheirus salmonis (Krøyer, 1838)). Immediately upon entering seawater, juvenile pink salmon preferred the top 1 m of the water column, but they moved significantly deeper down the vertical water column as seawater acclimation time increased. A significant diel migration pattern was observed, which involved a preference for the surface at night-time, compared with daytime. When fish in the column were exposed to L. salmonis copepodids for 3 h, 43%–62% of fish became infected, fish expanded their vertical distribution range, and significant changes in vertical distribution patterns were observed.

scholarly journals Mapping Asian anthropogenic emissions of non-methane volatile organic compounds to multiple chemical mechanisms

2013 ◽  
Vol 13 (12) ◽  
pp. 32649-32701 ◽  
Author(s):  
M. Li ◽  
Q. Zhang ◽  
D. G. Streets ◽  
K. B. He ◽  
Y. F. Cheng ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Individual Species ◽  
Chemical Mechanisms ◽  
Mixing Ratios ◽  
Wide Range ◽  
Oxygenated Volatile Organic Compounds ◽  
Volatile Organic ◽  
Species Mapping ◽  
Multiple Chemical

Abstract. An accurate speciation mapping of non-methane volatile organic compounds (NMVOC) emissions has an important impact on the performance of chemical transport models (CTMs) in simulating ozone mixing ratios and secondary organic aerosols. In this work, we developed an improved speciation framework to generate model-ready anthropogenic Asian NMVOC emissions for various gas-phase chemical mechanisms commonly used in CTMs by using an explicit assignment approach and updated NMVOC profiles, based on the total NMVOC emissions in the INTEX-B Asian inventory for the year 2006. NMVOC profiles were selected and aggregated from a wide range of new measurements and the SPECIATE database. To reduce potential uncertainty from individual measurements, composite profiles were developed by grouping and averaging source profiles from the same category. The fractions of oxygenated volatile organic compounds (OVOC) were corrected during the compositing process for those profiles which used improper sampling and analyzing methods. Emissions of individual species were then lumped into species in different chemical mechanisms used in CTMs by applying mechanism-dependent species mapping tables, which overcomes the weakness of inaccurate mapping in previous studies. Gridded emissions for eight chemical mechanisms are developed at 30 min × 30 min resolution using various spatial proxies and are provided through the website: http://mic.greenresource.cn/intex-b2006. Emission estimates for individual NMVOC species differ between one and three orders of magnitude for some species when different sets of profiles are used, indicating that source profile is the most important source of uncertainties of individual species emissions. However, those differences are diminished in lumped species as a result of the lumping in the chemical mechanisms.

scholarly journals Patterns of distribution and abundance of larval phosichthyidae (actinopterygii, stomiiformes) in southeastern Brazilian waters

2011 ◽  
Vol 59 (3) ◽  
pp. 213-229 ◽  
Author(s):  
Cássia Gôngora Goçalo ◽  
Mario Katsuragawa ◽  
Ilson Carlos Almeida da Silveira
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Distribution Patterns ◽  
Southeastern Brazil ◽  
Patterns Of Distribution ◽  
Oceanic Region ◽  
Brazil Current ◽  
Horizontal And Vertical Distribution

Horizontal and vertical distribution patterns and abundance of larval phosichthyids were investigated from oblique and depth-stratified towns off Southeastern brazilian waters, from São Tomé cape (41ºW.; 22ºS.) to São Sebastião island (45ºW.; 24ºS.). The sampling was performed during two cruises (January/2002 -summer; August/2002 -winter). Overall 538 larvae of Phosichthyidae were collected during summer and 158 in the winter. Three species, Pollichthys mauli, Vinciguerria nimbaria and Ichthyioccoccus sp. occurred in the area, but Ichthyioccoccus sp. was extremely rare represented by only one specimen, caught in the oceanic region during the summer. Geographically, larval were concentrated in the oceanic region, and vertically distributed mainly between the surface and 80 m depth in the summer and winter. Larvae were more abundant during the night, performing a diel vertical migration in the water column. The results suggest that the meandering and eddies of Brazil Current play important role on the transport and distribution patterns of larval phosichthyids over the oceanic and neritic area in the Southeastern Brazil.

Molecular and physiological comparison ofAzospirillumspp. isolated fromRhizoctonia solanimycelia, wheat rhizosphere, and human skin wounds

2004 ◽  
Vol 50 (4) ◽  
pp. 291-297 ◽  
Author(s):  
Michael F Cohen ◽  
Xiang Y Han ◽  
Mark Mazzola
Keyword(s):  
Rhizoctonia Solani ◽  
Azospirillum Brasilense ◽  
Type Strain ◽  
Apple Orchard ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Free Living ◽  
Root Pathogen ◽  
Wide Range ◽  
Orchard Soil

Four phenotypically similar bacterial strains isolated from fungal, plant, and human sources were identified as Azospirillum species. Strains RC1 and LOD4 were isolated from the mycelium of the apple root pathogen Rhizoctonia solani AG 5 and from the rhizosphere of wheat grown in apple orchard soil, respectively. Strains C610 and F4626 isolated from human wounds were previously misclassified as Roseomonas genomospecies 3 and 6. All four strains demonstrated close similarities in 16S rRNA gene sequences, having [Formula: see text]97% identity to Azospirillum brasilense type strain ATCC 29145 and <90% identity to Roseomonas gilardii, the Roseomonas type strain. Extensive phenotypic similarities among the four strains included the ability of free-living cells to fix N2. Cells of strains RC1, LOD4, and C610 but not of strain F4626 could be induced to flocculate by incubation with 10 mmol·L–1glycerol or fructose in medium containing 0.5 mmol·L–1NO3–. Our results indicate a wide range of potential sources for Azospirillum spp. with the isolation of Azospirillum spp. from human wounds warranting further investigation.Key words: Azospirillum brasilense, Roseomonas fauriae, flocculation, Rhizoctonia solani.

scholarly journals Evolution of pathogen and parasite avoidance behaviours

2018 ◽  
Vol 373 (1751) ◽  
pp. 20170256 ◽  
Author(s):  
Cecile Sarabian ◽  
Val Curtis ◽  
Rachel McMullan
Keyword(s):  
Avoidance Behaviour ◽  
Disease Avoidance ◽  
Behavioural Science ◽  
Free Living ◽  
Society Meeting ◽  
Neural Architecture ◽  
Trade Offs ◽  
Wide Range ◽  
Parasite Avoidance ◽  
Behavioural Adaptations

All free-living animals are subject to intense selection pressure from parasites and pathogens resulting in behavioural adaptations that can help potential hosts to avoid falling prey to parasites. This special issue on the evolution of parasite avoidance behaviour was compiled following a Royal Society meeting in 2017. Here we have assembled contributions from a wide range of disciplines including genetics, ecology, parasitology, behavioural science, ecology, psychology and epidemiology on the disease avoidance behaviour of a wide range of species. Taking an interdisciplinary and cross-species perspective allows us to sketch out the strategies, mechanisms and consequences of parasite avoidance and to identify gaps and further questions. Parasite avoidance strategies must include avoiding parasites themselves and cues to their presence in conspecifics, heterospecifics, foods and habitat. Further, parasite avoidance behaviour can be directed at constructing parasite-retardant niches. Mechanisms of parasite avoidance behaviour are generally less well characterized, though nematodes, rodents and human studies are beginning to elucidate the genetic, hormonal and neural architecture that allows animals to recognize and respond to cues of parasite threat. While the consequences of infection are well characterized in humans, we still have much to learn about the epidemiology of parasites of other species, as well as the trade-offs that hosts make in parasite defence versus other beneficial investments like mating and foraging. Finally, in this overview we conclude that it is legitimate to use the word ‘ disgust' to describe parasite avoidance systems, in the same way that ‘fear' is used to describe animal predator avoidance systems. Understanding disgust across species offers an excellent system for investigating the strategies, mechanisms and consequences of behaviour and could be a vital contribution towards the understanding and conservation of our planet's ecosystems. This article is part of the Theo Murphy meeting issue ‘Evolution of pathogen and parasite avoidance behaviours'.

On the lack of widespread bottom simulating reflectors in the Mediterranean Basin

2021 ◽  
Author(s):  
Cristina Corradin ◽  
Angelo Camerlenghi ◽  
Michela Giustiniani ◽  
Umberta Tinivella ◽  
Claudia Bertoni
Keyword(s):  
Water Column ◽  
Pore Water ◽  
Mediterranean Basin ◽  
Stability Field ◽  
Hydrocarbon Gases ◽  
Wide Range ◽  
Bottom Simulating Reflectors ◽  
Messinian Evaporites ◽  
The Mediterranean ◽  
The Mediterranean Basin

&lt;p&gt;In the Mediterranean Basin, gas hydrate bottom simulating reflectors (BSR) are absent, with very few and spatially limited exceptions occurring in Eastern Mediterranean mud volcanoes and in the Nile deep sea fan. This is in spite of widespread occurrence of hydrocarbon gases in the subsurface, mainly biogenic methane, from a wide range of stratigraphic intervals.&lt;br&gt;In this study we model the methane hydrate stability field using all available information on DSDP and ODP boreholes in the Western Mediterranean and in the Levant Basin, including the downhole changes of pore water salinity. The models take into account the consequent pore water density changes and use known estimates of geothermal gradient. None of the drilled sites were located on seismic profiles in which a BSR is present.&lt;br&gt;The modelled base of the stability field of methane hydrates is located variably within, below, or even above the drilled sedimentary section (the latter case implies that it is located in the water column). We discuss the results in terms of geodynamic environments, areal distribution of Messinian evaporites, upward ion diffusion from Messinian evaporites, organic carbon content, and the peculiar thermal structure of the Mediterranean water column. &lt;br&gt;We conclude that the cumulative effects of geological and geochemical environments make the Mediterranean Basin a region that is unfavorable to the existence of BSRs in the seismic record, and most likely to the existence of natural gas hydrates below the seabed.&lt;br&gt;&lt;br&gt;&lt;/p&gt;

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