scholarly journals The Role of Biotic and Abiotic Factors in Prevalence of Cyprinidae Fishes and Trout Parasites in the Fish Farms of Azerbaijan

2021 ◽  
Vol 7 (4) ◽  
Author(s):  
A. Suleymanova
Keyword(s):  
Abiotic Factors ◽  
Fish Parasites ◽  
Pathogenic Species ◽  
Fish Farms ◽  
Factors Affecting ◽  
Causative Agents ◽  
Hot Season ◽  
Chemical Conditions ◽  
Physical And Chemical

During 2013–2017 years biotic and abiotic of environmental conditions affecting to the extensiveness of invasion by causative agents of carp and trout parasitosis in fish farms in the territory of Azerbaijan Republic were studied. In addition, we studied the seasonal and age dynamics of diseases of the farm fishes. The prevalence of fish parasites infection in hot season (May-July) in comparison with cold month (October) was recorded. Twenty species of parasites from various systematical groups were found: protozoans (4 species); monogenean worms (3 species); cestodes (4 species); trematodes (3 species); nematodes (2 species); acanthocephalans (2 species); crustaceans (2 species). All investigations were conducted by considering of various factors affecting on production of fish. 386 specimens of carp and 415 specimens of trout were examined by the method of full parasitological dissection. We analyzed the physical and chemical conditions of water from the fish pools and other artificial basins in fish farms. In conclusion of our investigation the list of most pathogenic species of cultivated parasites were composed: Metechinorhyncnus truttae, Acanthocephalus clavulae, Paradilepis scolecina, Proteocephalus torulosus, Rhabdochon agnedini.

Assessing the role of nudging, aerosols and run-up time in medicane simulations with WRF

2020 ◽  
Author(s):  
Juan José Gómez-Navarro ◽  
Enrique Pravia-Sarabia ◽  
Juan Pedro Montávez
Keyword(s):  
Small Scale ◽  
Factors Affecting ◽  
Chemical Mechanisms ◽  
Spectral Nudging ◽  
On Line ◽  
Precise Prediction ◽  
Considerable Impact ◽  
Run Up ◽  
Physical And Chemical

<p>Medicanes are small-scale cyclones with tropical characteristics that take place in the Mediterranean basin, showing hazardous features such as intense wind gusts and precipitation. Our ability to predict their consequences is of great importance for those cases of medicanes reaching coastal inhabited areas. Succeeding in a precise prediction of their characteristics is heavily subject to getting insight in the fundamental factors that are involved in their genesis, strengthening and maintenance. Given their small nature compared to the synoptic scale, RCMs are specially suitable for the simulation of these storms. However, when using RCMs, there are a number of configurations that must be controlled to specify the way the different physical and chemical mechanisms are solved during the simulation.<br><br><br>In this work, we evaluate the role of three different factors affecting the outcome of WRF, namely the run-up time, the inclusion or not of the on-line simulation of aerosols and the use of spectral nudging. To that end, six different medicanes have been simulated combining different possibilities for the aforementioned factors, resulting in a set of above 360 simulations. Although in principle the on-line simulation of aerosols is expected to have the strongest impact in the simulation of medicanes, it turns out that the run-up time -time delay from the simulation start to the medicane maximum intensity moment- is far more decisive in their successful development than the former. The results are also sensible to the use of spectral nudging, and the three considered factors end up having a considerable impact. Indeed, whereas the majority of their combinations lead to an erratic reproduction of the observed medicanes, there exist some combinations that allow reasonable results, showing that these configurations are in fact interdependent, i.e., the change in the simulation outcome due to a different configuration for one of the factors is dependent on the configuration of the others. This complicates the assessment on the influence of one factor alone, but facilitates gaining insight on the factors that control the genesis and maintenance of medicanes.</p>

scholarly journals Spatiotemporal Distribution of Marine Magnetotactic Bacteria in a Seasonally Stratified Coastal Salt Pond

2004 ◽  
Vol 70 (10) ◽  
pp. 6230-6239 ◽  
Author(s):  
S. L. Simmons ◽  
S. M. Sievert ◽  
R. B. Frankel ◽  
D. A. Bazylinski ◽  
K. J. Edwards
Keyword(s):  
Alternative Model ◽  
Physiological Role ◽  
Magnetotactic Bacteria ◽  
Respiratory Metabolism ◽  
Population Abundance ◽  
Seasonal Fluctuations ◽  
Salt Pond ◽  
Chemical Conditions ◽  
Physical And Chemical

ABSTRACT The occurrence and distribution of magnetotactic bacteria (MB) were studied as a function of the physical and chemical conditions in meromictic Salt Pond, Falmouth, Mass., throughout summer 2002. Three dominant MB morphotypes were observed to occur within the chemocline. Small microaerophilic magnetite-producing cocci were present at the top of the chemocline, while a greigite-producing packet-forming bacterium occurred at the base of the chemocline. The distributions of these groups displayed sharp changes in abundance over small length scales within the water column as well as strong seasonal fluctuations in population abundance. We identified a novel, greigite-producing rod in the sulfidic hypolimnion that was present in relatively constant abundance over the course of the season. This rod is the first MB that appears to belong to the γ-Proteobacteria, which may suggest an iron- rather than sulfur-based respiratory metabolism. Its distribution and phylogenetic identity suggest that an alternative model for the ecological and physiological role of magnetotaxis is needed for greigite-producing MB.

scholarly journals Biofilms Confer Resistance to Simulated Extra-terrestrial Geochemical Extremes

2017 ◽  
Author(s):  
Adam H. Stevens ◽  
Delma Childers ◽  
Mark Fox-Powell ◽  
Charles S. Cockell
Keyword(s):  
Planktonic Cells ◽  
Planetary Protection ◽  
Aqueous Environments ◽  
Groundwater Systems ◽  
Acidic Conditions ◽  
High Sulfate ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
Over Time

1AbstractBiofilms improve microbes’ resistance to a variety of extreme physical and chemical conditions on Earth. The discovery of putative aqueous environments on other planetary bodies such as Mars motivates an interest in understanding the viability of life, and the potential role of biofilms, in previously unexplored geochemical extremes. We investigated the loss of viability of planktonic cells and biofilms ofSphingomonas desiccabilis(a Gram-negative, desiccation resistant, soil crust-forming organism) to simulated Martian brines. These brines were produced from geochemical modelling of past aqueous environments on Mars, and their high sulfate concentrations make them different to most terrestrial brines, although similar briny environments have been found in locations such as the Basque Lakes in Canada or in deep subsurface groundwater systems. Biofilms grown on basaltic scoria were subjected to the simulated martian brines and the viability of cells was measured over time and compared to equivalent planktonic cultures. Crystal violet assay was used to measure how the biomass of the biofilms changed over time in response to the brines. While certain brines were highly hostile to microbial viability, we found that biofilms that were desiccated prior to being treated with brines maintained viability over a longer treatment period when compared to planktonic cells. Our results show that biofilms confer short-term protection to the harsh osmotic, ionic, and acidic conditions of Mars-relevant brines. However, in the most extreme simulated brines, even biofilms eventually lost viability. By demonstrating that biofilms confer protection to conditions that are potentially analogous to current day recurrent slope lineae (thought to be produced by the flow of briny fluids) on Mars, our results show that contaminant biofilm-forming microorganisms may have a greater chance of surviving in so-called ‘Special Regions’ on Mars, with implications for planetary protection in missions that aim to explore these regions.

scholarly journals Numerical simulation of orthosilicic acid polycondensation and silica particles formation inhydrothermal solutions

2019 ◽  
pp. 18-28 ◽  
Author(s):  
V. V. Potapov ◽  
A. A. Cerdan ◽  
I. A. Kashutina
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Silica Particles ◽  
Orthosilicic Acid ◽  
Mineral Formation ◽  
Mineral Synthesis ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
Hydrothermal Mineral

Numerical simulation of the process of polycondensation of orthosilicic acid and colloid silica particles growth under different physical and chemical conditions was done: temperature, pH, ionic strength and other. Calculated dependences of orthosilicic acid concentration and mean radius of silica particles versus time, graphs of particles dimensions distributions were received. Results of calculations were compared with experimental data. Research is important for to make clear role of colloid silica on hydrothermal mineral formation and for industrial extraction and utilization of silica, and also for mineral synthesis.

scholarly journals Periphytic algae in a floodplain lake and river under low water conditions

2016 ◽  
Vol 16 (3) ◽  
Author(s):  
Andressa Bichoff ◽  
Nicolli Cristina Osório ◽  
Bárbara Dunck ◽  
Liliana Rodrigues
Keyword(s):  
Aquatic Macrophyte ◽  
Abiotic Factors ◽  
Abundant Species ◽  
Algal Community ◽  
Nitzschia Palea ◽  
Periphytic Algae ◽  
Eichhornia Azurea ◽  
Drought Conditions ◽  
Chemical Conditions ◽  
Physical And Chemical

Abstract Drought events will become more frequent due the climate change. In floodplains, periphytic algae are responsible for part of the primary production, are the principal source of organic carbon deposition, play an important role in mineralization and nutrient cycling, and are the base of the food web for many organisms. As algae distribution in aquatic environments is a strong indicator of physical and chemical conditions of the sites, we aimed to determine the structure of periphytic algae in lentic and lotic environments during drought conditions and to uncover the main local abiotic factors in community structuring. We hypothesized diatoms would be more frequent than green algae and desmids at both sites, due to their resistance characteristics, and that higher periphyton algal richness, density and diversity would occur in the lake due to the greater availability of nutrients and the absence of flow. The study was carried out in the Finado Raimundo lake and the Ivinhema river in the Upper Paraná river floodplain during the low water period of 2011. Petioles of the aquatic macrophyte Eichhornia azurea (Sw.) Kunth were used as a substrate for periphytic algae. We found a total of 171 species, 104 species in the lake and 80 in the river. Diatoms were predominant at both sites due to their strategic traits, and between sites, there were different patterns in the periphytic algal community structure, owing to the distinctive physical and chemical characteristics of the lake and the river. Achnanthidium minutissimum (Kützing) Czarnecki and Nitzschia palea (Kützing) W. Smith were the most abundant species in both environments. Our results showed patterns of periphytic algae in a floodplain during drought conditions, which will assist in understanding their structuring during future drought scenarios.

scholarly journals Biodiversity of the metazoan parasites of Prochilodus lineatus (Valenciennes, 1837) (Characiformes: Prochilodontidae) in anthropized environments from the Batalha River, São Paulo State, Brazil

2018 ◽  
Vol 18 (3) ◽  
Author(s):  
Lucas Aparecido Rosa Leite ◽  
Larissa Sbeghen Pelegrini ◽  
Beatriz Narciso Agostinho ◽  
Rodney Kozlowiski de Azevedo ◽  
Vanessa Doro Abdallah
Keyword(s):  
Ecosystem Health ◽  
Parasite Species ◽  
Structural Characteristics ◽  
Fish Parasites ◽  
Fish Farms ◽  
Metazoan Parasites ◽  
Prochilodus Lineatus ◽  
Parasitic Fauna ◽  
Environment Quality

Abstract: Biodiversity of fish parasites is a field of significant growth worldwide, whether due to the advancement of fish farms or the important role of these organisms as indicators of environment quality and ecosystem health, making them useful tools in the conservation and maintenance of the biodiversity as a whole. The objectives of this study were to evaluate the structure and composition of the parasitic fauna of Prochilodus lineatus collected from two structurally distinct stretches of the Batalha River. Fifty specimens of P. lineatus were collected between June 2015 and June 2016. Of these 50 hosts, 875 parasite specimens were collected, divided into 30 species, belonging to seven groups: Myxozoa, Monogenea, Digenea, Acanthocephala, Nematoda, Copepoda and Hirudinea. In addition to new records of known parasites of P. lineatus for this locality, 13 species were newly recorded parasitizing this fish, including a new monogenean species (Tereancistrum sp. n.), with Monogenea being the most representative class in the study. The findings of this study expands the known geographic distribution of these parasite species and helps to increase the knowledge of the biodiversity of these organisms in different hosts and environments. In general, the structure and composition of the P. lineatus parasitic fauna did not seem to be influenced by the structural characteristics of the two stretches studied, due to the migratory habits of the host.

scholarly journals Primorskoye epithermal Ag-Au deposit (Northeast of Russia): geologic aspects, mineralogic and geochemical features, and ore formation conditions

2019 ◽  
Vol 61 (1) ◽  
pp. 52-74
Author(s):  
N. E. Savva ◽  
A. V. Volkov ◽  
A. A. Sidorov ◽  
E. E. Kolova ◽  
K. Yu. Murashov
Keyword(s):  
High Temperature ◽  
Elevated Concentration ◽  
Epithermal Deposit ◽  
Ore Formation ◽  
Low Concentrations ◽  
Formation Conditions ◽  
High Concentrations ◽  
Chemical Conditions ◽  
Physical And Chemical

As a potentially large Ag-Au epithermal deposit, Primorskoye comprises the following three areas: Kholodny, Spiridonych, and Teply. This deposit is located in the Omsukchan district of the Magadan Region, where similar deposits, including Dukat, Lunnoye, Goltsovoye, Arylakh, Tidit, and Perevalnoye, have developed. The deposit can be attributed to the Kalalagian volcano-tectonic depression and is localized in a flat-lying rock mass in the Late Cretaceous ignimbrites and rhyolites having thicknesses of greater than 700 m, which is cut through by numerous dykes of medium and major composition. According to the drilling data, the solid mass of leucocratic granites is located in deposits at a depth of 400–500 m with outcrops in the northeastern part of the ore field. The presence of Bi-containing galena and matildite, the availability of mid and high temperature facies of metasomatites (epidote and actinolite), and the specific physical and chemical conditions during the formation of the epithermal Ag-Au ores indicate the intrusive position above and the role of granitoids as generators of high temperature magmatic fluids, which introduced Bi and heated the rocks enclosing the mineralization. The geochemical features of the ores are well correlated with their mineral compositions. The high concentrations of Mn and Ag, elevated concentration of Au, low concentrations of Cu, Pb, Zn, Sb, As, Bi, and Te, low sum of REE, and negative Eu- and positive Се-anomalies were observed. The high values of the Te/Se, Sr/Ba, Y/Ho, and U/Th indicators in the ores are associated with the deposit location in the zone of granitoid massif effect. Further, the physical and chemical parameters of ore formation in the Teply area are unusual and are characterized by high temperatures, low concentrations of salts, and fluid density, which are indicative of the typical “dry steam” conditions. The obtained results allow the Primorskoye epithermal deposit to be attributed to the intermediate class. The information present in the article is practically valuable for the regional forecast and metallogenic developments as well as for searching and assessing the epithermal Ag-Au deposits.

Nitrification potential in waste stabilisation ponds: comparison of a secondary and tertiary pond system

2010 ◽  
Vol 61 (3) ◽  
pp. 781-788 ◽  
Author(s):  
A. Yamamoto ◽  
M. D. Short ◽  
B. van den Akker ◽  
N. J. Cromar ◽  
H. J. Fallowfield
Keyword(s):  
Nitrogen Cycling ◽  
Field Experiments ◽  
Waste Stabilisation Ponds ◽  
Nitrification Potential ◽  
Laboratory Microcosm ◽  
Natural Pond ◽  
Chemical Conditions ◽  
Physical And Chemical

This study compared the nitrification potential of two separate Waste Stabilisation Ponds (WSPs) operating under differing physical and chemical conditions. In order to probe the nitrification potential of each system, the oxidation of ammonium and also the intermediate product nitrite was assessed using both in situ and laboratory micro-scale incubations. The role of sediment in determining the nitrification potential of the two WSPs was also investigated. Results from laboratory microcosm incubations revealed a competent and strikingly similar nitrification potential for both WSPs in spite of their differing nitrogen and organic loadings, and also suggested a significant role for sediment in WSP nitrogen cycling. Results from in situ field experiments identified biomass uptake to be the dominant nitrogen removal mechanism in natural pond environments. Other aspects of WSP nitrogen cycling are also discussed.

scholarly journals Gall-forming aphids are protected (and benefit) from defoliating caterpillars: the role of plant-mediated mechanisms

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lilach Kurzfeld-Zexer ◽  
Moshe Inbar
Keyword(s):  
Interspecific Interactions ◽  
Abiotic Factors ◽  
Protective Role ◽  
Insect Herbivores ◽  
Young Leaves ◽  
Feeding Trials ◽  
Leaf Flush ◽  
Gall Induction ◽  
Physical And Chemical

Abstract Background Interspecific interactions among insect herbivores are common and important. Because they are surrounded by plant tissue (endophagy), the interactions between gall-formers and other herbivores are primarily plant-mediated. Gall-forming insects manipulate their host to gain a better nutrient supply, as well as physical and chemical protection form natural enemies and abiotic factors. Although often recognized, the protective role of the galls has rarely been tested. Results Using an experimental approach, we found that the aphid, Smynthurodes betae, that forms galls on Pistacia atlantica leaves, is fully protected from destruction by the folivorous processionary moth, Thaumetopoea solitaria. The moth can skeletonize entire leaves on the tree except for a narrow margin around the galls that remains intact (“trimmed galls”). The fitness of the aphids in trimmed galls is unharmed. Feeding trials revealed that the galls are unpalatable to the moth and reduce its growth. Surprisingly, S. betae benefits from the moth. The compensatory secondary leaf flush following moth defoliation provides new, young leaves suitable for further gall induction that increase overall gall density and reproduction of the aphid. Conclusions We provide experimental support for the gall defense hypothesis. The aphids in the galls are protracted by plant-mediated mechanisms that shape the interactions between insect herbivores which feed simultaneously on the same host. The moth increase gall demsity on re-growing defoliated shoots.

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