Viruses in aquatic ecosystems: important advancements of the last 20 years and prospects for the future in the field of microbial oceanography and limnology

Over the last two decades, viruses in aquatic systems have been observed to modify, influence and control aquatic systems. Since the determination decades ago that viruses were abundant in aquatic ecosystems, researchers have demonstrated that viruses are pervasive and dynamic across the expanse and depth of all aquatic systems as well as at the water-sediment interface. There have been a wide range of methodological advancements during this time. To date, aquatic viruses have been suggested to play vital roles in global and small-scale biogeochemical cycling, community structure, algal bloom termination, gene transfer, and evolution of aquatic organisms. Even in harsh and difficult to study environments, aquatic and benthic viruses have been demonstrated to be major players in carbon cycling and recycling of nutrients from organic material. Taxonomic and metagenomic research has shown us that there are major globally-distributed groups, but that their genomes are filled with sequence information that has no similarity to sequences in existing bioinformatic databases. And while the field of viral ecology has expanded exponentially since the late 1980s, there is much that we do not yet understand about virusmediated processes in aquatic systems. Important near-term steps include the combination of advanced metagenomic techniques with studies of function and population control, standardization of methodological approaches to facilitate global data acquisition without concern over methods-based artefacts, understanding of viral life strategies and their triggers, and the role of viruses in the transformation of organic matter. The purpose of this manuscript is to bring the reader a review of the recent advances in aquatic viral ecology in light of new areas of research, applications of viral ecology to real-world problems, and refinement of models of viral interactions on a range of scales.

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Influences of nanoparticles on aquatic organisms: Current situation of nanoparticles effects in aquatic ecosystems

Sustainable Engineering and Innovation, ISSN 2712-0562 ◽

10.37868/sei.v3i1.id136 ◽

2021 ◽

Vol 3 (1) ◽

pp. 54-60

Author(s):

Didem Gökçe

Keyword(s):

Aquatic Ecosystems ◽

Aquatic Organisms ◽

High Reactivity ◽

Freshwater Ecosystems ◽

Engineered Nanoparticles ◽

Adverse Impacts ◽

Wide Range ◽

Mean Size ◽

Level Of Aggregation ◽

Physical And Chemical

The quick improvement of nanotechnology permits a wide range of utilization of engineered nanoparticles, such as personal care products, medicals, optics, electronics, and automobiles. The nanoparticles manufactured from Ag, Au carbon-nanotube, ZnO, SiO2, TiO2, Cu, Ni, and magnetic ferrites are among the generally utilized in products. The nanoparticles are produced and utilized in large quantities and release into marine and freshwater ecosystems during production, use, discharge, treatment, and deposition. Those particles with a mean size of 1 nm - 100 nm are of potential environmental risks because of their particular qualifications and high reactivity although their great economical values. Based on the studies, the size, shape, and surface physical and chemical characteristics of the nanoparticles show the level of aggregation, solubility, structural and chemical composition, the importance of the use of nanoparticles, and their toxicity with biological systems. Nanoparticles can potentially cause adverse impacts on tissue, cellular, genetic materials, and protein- enzyme levels due to their unique physical and chemical qualifications. In this study, the effects of nanoparticles on aquatic organisms and aquatic ecosystems were evaluated.

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What Do We Know About Toxigenic, Bloom-Forming Cyanobacteria at the Beginning of The 21st Century?

Environmental Analysis & Ecology Studies ◽

10.31031/eaes.2018.02.000529 ◽

2018 ◽

Vol 2 (1) ◽

Author(s):

Magdalena Toporowska

Keyword(s):

Aquatic Ecosystems ◽

Climate Changes ◽

Aquatic Organisms ◽

Biologically Active ◽

Cyanobacterial Blooms ◽

Brackish Waters ◽

Human Health Risks ◽

Cyanobacterial Species ◽

Wide Range ◽

Review Reports

Cyanobacteria are microscopic, prokaryotic organisms capable of mass development in aquatic ecosystems. Cyanobacterial blooms, observed often in various fresh and brackish waters, are growing global problem due to the eutrophication process and climate changes. Different cyanobacterial species may produce wide range of various biologically active secondary metabolites, which may be harmful to aquatic organisms, animals and humans. Microcystins (MCs) are the most known and frequently studied cyanobacterial compounds classified to cyanotoxins. But cyanobacteria are producers of several hundred of other toxins (e.g. nodularins, cylindrospermopsins, anatoxins, saxitoxins), and potentially harmful substances (e.g. oligopeptides other than MCs). In this paper, the present knowledge about cyanobacterial blooms, toxins and other metabolites is shown concisely with references to the latest review reports broadly describing the issues discussed. Human health risks caused by cyanobacteria is also presented

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Effects of mancozeb on the testicular histology of the zebrafish (Danio rerio)

Annales de Limnologie - International Journal of Limnology ◽

10.1051/limn/2020009 ◽

2020 ◽

Vol 56 ◽

pp. 10

Author(s):

Merve Abar Gürol ◽

Sezgi Arman ◽

Nazan Deniz Yön

Keyword(s):

Danio Rerio ◽

Aquatic Ecosystems ◽

Aquatic Organisms ◽

Reproductive Activity ◽

Field Crops ◽

Wide Range ◽

Hematoxylin And Eosin ◽

Population Continuity ◽

Testicular Histology ◽

Reproductive Activities

Reproduction is a critical and sensitive process for population continuity of the externally fertilizing aquatic organisms. Environmental pollution may adversely effect the reproductive activities of fish. Pesticides are the mobile chemicals that are known to pollute the aquatic ecosystems. Mancozeb is an ethylene-bis-dithiocarbamate (EBDC) fungicide that is frequently used to protect fruits, vegetables, vineyards and field crops against a wide range of fungal diseases. The aim of the current work was to evaluate the acute toxic effects of mancozeb on the testis tissues of zebrafish (Danio rerio). Zebrafish were exposed to 5 ppm and 7.5 ppm of mancozeb concentrations for five days. Testis tissues were removed and fixed in 10% neutral buffered formalin solution. Specimens were embedded in paraffin and 5 μm serial sections were stained with hematoxylin and eosin. The control and the experimental samples were investigated by light microscopy and histopathological changes were evaluated. Mancozeb gave rise to degenerative spermatogenic cells, seminiferous tubule disorganizations, fibrosis, hemorrhage, vacuolization, hypertrophy of spermatocytes, edema, decreased spermatogenic cell clusters and sperms, pyknotic and karyolytic nuclei. These results showed that mancozeb could interrupt the reproductive activity and decrease the fertilization ratio of zebrafish.

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Integrated Design and Multi-Objective Optimization of a Single Stage Heat-Pump Turbocompressor

Volume 3B: 39th Design Automation Conference ◽

10.1115/detc2013-12180 ◽

2013 ◽

Author(s):

J. Schiffmann

Keyword(s):

Design Optimization ◽

High Efficiency ◽

Integrated Design ◽

Heat Pumps ◽

Small Scale ◽

Multi Objective Optimization ◽

Design Constraints ◽

Multi Objective ◽

Wide Range ◽

Standard Design

Small scale turbomachines in domestic heat pumps reach high efficiency and provide oil-free solutions which improve heat-exchanger performance and offer major advantages in the design of advanced thermodynamic cycles. An appropriate turbocompressor for domestic air based heat pumps requires the ability to operate on a wide range of inlet pressure, pressure ratios and mass flows, confronting the designer with the necessity to compromise between range and efficiency. Further the design of small-scale direct driven turbomachines is a complex and interdisciplinary task. Textbook design procedures propose to split such systems into subcomponents and to design and optimize each element individually. This common procedure, however, tends to neglect the interactions between the different components leading to suboptimal solutions. The authors propose an approach based on the integrated philosophy for designing and optimizing gas bearing supported, direct driven turbocompressors for applications with challenging requirements with regards to operation range and efficiency. Using previously validated reduced order models for the different components an integrated model of the compressor is implemented and the optimum system found via multi-objective optimization. It is shown that compared to standard design procedure the integrated approach yields an increase of the seasonal compressor efficiency of more than 12 points. Further a design optimization based sensitivity analysis allows to investigate the influence of design constraints determined prior to optimization such as impeller surface roughness, rotor material and impeller force. A relaxation of these constrains yields additional room for improvement. Reduced impeller force improves efficiency due to a smaller thrust bearing mainly, whereas a lighter rotor material improves rotordynamic performance. A hydraulically smoother impeller surface improves the overall efficiency considerably by reducing aerodynamic losses. A combination of the relaxation of the 3 design constraints yields an additional improvement of 6 points compared to the original optimization process. The integrated design and optimization procedure implemented in the case of a complex design problem thus clearly shows its advantages compared to traditional design methods by allowing a truly exhaustive search for optimum solutions throughout the complete design space. It can be used for both design optimization and for design analysis.

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Toxic or Not Toxic, That Is the Carbon Quantum Dot’s Question: A Comprehensive Evaluation with Zebrafish Embryo, Eleutheroembryo, and Adult Models

Polymers ◽

10.3390/polym13101598 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1598

Author(s):

Chih-Yu Chung ◽

Yu-Ju Chen ◽

Chia-Hui Kang ◽

Hung-Yun Lin ◽

Chih-Ching Huang ◽

...

Keyword(s):

Zebrafish Embryo ◽

Comprehensive Evaluation ◽

Aquatic Organisms ◽

Carbon Quantum Dots ◽

Adult Zebrafish ◽

Fish Embryo ◽

Wide Range ◽

Different Types ◽

Low Toxicity

Carbon quantum dots (CQDs) are emerging novel nanomaterials with a wide range of applications and high biocompatibility. However, there is a lack of in-depth research on whether CQDs can cause acute or long-term adverse reactions in aquatic organisms. In this study, two different types of CQDs prepared by ammonia citrate and spermidine, namely CQDAC and CQDSpd, were used to evaluate their biocompatibilities. In the fish embryo acute toxicity test (FET), the LD50 of CQDAC and CQDSpd was about 500 and 100 ppm. During the stage of eleutheroembryo, the LD50 decreased to 340 and 55 ppm, respectively. However, both CQDs were quickly eliminated from embryo and eleutheroembryo, indicating a lack of bioaccumulation. Long-term accumulation of CQDs was also performed in this study, and adult zebrafish showed no adverse effects in 12 weeks. In addition, there was no difference in the hatchability and deformity rates of offspring produced by adult zebrafish, regardless of whether they were fed CQDs or not. The results showed that both CQDAC and CQDSpd have low toxicity and bioaccumulation to zebrafish. Moreover, the toxicity assay developed in this study provides a comprehensive platform to assess the impacts of CQDs on aquatic organisms in the future.

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The Role of Aquatic Ecosystems (River Tua, Portugal) as Reservoirs of Multidrug-Resistant Aeromonas spp.

Water ◽

10.3390/w13050698 ◽

2021 ◽

Vol 13 (5) ◽

pp. 698

Author(s):

Sónia Gomes ◽

Conceição Fernandes ◽

Sandra Monteiro ◽

Edna Cabecinha ◽

Amílcar Teixeira ◽

...

Keyword(s):

Antibiotic Resistance ◽

Antimicrobial Resistance ◽

Nalidixic Acid ◽

Water Samples ◽

Aquatic Ecosystems ◽

Anthropogenic Activities ◽

Aquatic Organisms ◽

Resistant Bacteria ◽

Anthropogenic Pressures ◽

Resistance Rates

The inappropriate use of antibiotics, one of the causes of the high incidence of antimicrobial-resistant bacteria isolated from aquatic ecosystems, represents a risk for aquatic organisms and the welfare of humans. This study aimed to determine the antimicrobial resistance rates among riverine Aeromonas spp., taken as representative of the autochthonous microbiota, to evaluate the level of antibacterial resistance in the Tua River (Douro basin). The prevalence and degree of antibiotic resistance was examined using motile aeromonads as a potential indicator of antimicrobial susceptibility for the aquatic environment. Water samples were collected from the middle sector of the river, which is most impacted area by several anthropogenic pressures. Water samples were plated on an Aeromonas-selective agar, with and without antibiotics. The activity of 19 antibiotics was studied against 30 isolates of Aeromonas spp. using the standard agar dilution susceptibility test. Antibiotic resistance rates were fosfomycin (FOS) 83.33%, nalidixic acid (NA) 60%, cefotaxime (CTX) 40%, gentamicin (CN) 26.67%, tobramycin (TOB) 26.67%, cotrimoxazole (SXT) 26.67%, chloramphenicol (C) 16.67%, and tetracycline (TE) 13.33%. Some of the nalidixic acid-resistant strains were susceptible to fluoroquinolones. Multiple resistance was also observed (83.33%). The environmental ubiquity, the natural susceptibility to antimicrobials and the zoonotic potential of Aeromonas spp. make them optimal candidates for studying antimicrobial resistance (AMR) in aquatic ecosystems. Aquatic environments may provide an ideal setting for the acquisition and dissemination of antibiotic resistance because anthropogenic activities frequently impact them. The potential risk of multi- and pan-resistant bacteria transmission between animals and humans should be considered in a “One Health—One World” concept.

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Applications of Coupled Fixed Points for Multivalued Maps in the Equilibrium in Duopoly Markets and in Aquatic Ecosystems

Axioms ◽

10.3390/axioms10020044 ◽

2021 ◽

Vol 10 (2) ◽

pp. 44

Author(s):

Gana Gecheva ◽

Miroslav Hristov ◽

Diana Nedelcheva ◽

Margarita Ruseva ◽

Boyan Zlatanov

Keyword(s):

Fixed Points ◽

Aquatic Ecosystems ◽

Market Equilibrium ◽

Multivalued Maps ◽

New Class ◽

Wide Range ◽

Coupled Fixed Points ◽

Ordered Pairs ◽

Duopoly Markets

We have obtained a new class of ordered pairs of multivalued maps that have pairs of coupled fixed points. We illustrate the main result with two examples that cover a wide range of models. We apply the main result in models in duopoly markets to get a market equilibrium and in aquatic ecosystems, also to get an equilibrium.

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A broadbanded pressure differential wave energy converter based on dielectric elastomer generators

Nonlinear Dynamics ◽

10.1007/s11071-021-06721-8 ◽

2021 ◽

Author(s):

Michele Righi ◽

Giacomo Moretti ◽

David Forehand ◽

Lorenzo Agostini ◽

Rocco Vertechy ◽

...

Keyword(s):

Wave Energy ◽

Large Deformations ◽

Dielectric Elastomer ◽

Wave Energy Converter ◽

Pressure Differential ◽

Design Stage ◽

Small Scale ◽

Energy Converter ◽

Wide Range ◽

The Waves

AbstractDielectric elastomer generators (DEGs) are a promising option for the implementation of affordable and reliable sea wave energy converters (WECs), as they show considerable promise in replacing expensive and inefficient power take-off systems with cheap direct-drive generators. This paper introduces a concept of a pressure differential wave energy converter, equipped with a DEG power take-off operating in direct contact with sea water. The device consists of a closed submerged air chamber, with a fluid-directing duct and a deformable DEG power take-off mounted on its top surface. The DEG is cyclically deformed by wave-induced pressure, thus acting both as the power take-off and as a deformable interface with the waves. This layout allows the partial balancing of the stiffness due to the DEG’s elasticity with the negative hydrostatic stiffness contribution associated with the displacement of the water column on top of the DEG. This feature makes it possible to design devices in which the DEG exhibits large deformations over a wide range of excitation frequencies, potentially achieving large power capture in a wide range of sea states. We propose a modelling approach for the system that relies on potential-flow theory and electroelasticity theory. This model makes it possible to predict the system dynamic response in different operational conditions and it is computationally efficient to perform iterative and repeated simulations, which are required at the design stage of a new WEC. We performed tests on a small-scale prototype in a wave tank with the aim of investigating the fluid–structure interaction between the DEG membrane and the waves in dynamical conditions and validating the numerical model. The experimental results proved that the device exhibits large deformations of the DEG power take-off over a broad range of monochromatic and panchromatic sea states. The proposed model demonstrates good agreement with the experimental data, hence proving its suitability and effectiveness as a design and prediction tool.

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A Threat of Farmers’ Suicide and the Opportunity in Organic Farming for Sustainable Agricultural Development in India

Sustainability ◽

10.3390/su11082400 ◽

2019 ◽

Vol 11 (8) ◽

pp. 2400 ◽

Cited By ~ 4

Author(s):

Karthikeyan Mariappan ◽

Deyi Zhou

Keyword(s):

Organic Farming ◽

Tamil Nadu ◽

Agricultural Development ◽

Small Scale ◽

Conventional Farming ◽

Wide Range ◽

Significant Difference ◽

Small Scale Farmers ◽

The Cost ◽

Input Cost

Agriculture is the main sources of income for humans. Likewise, agriculture is the backbone of the Indian economy. In India, Tamil Nadu regional state has a wide range of possibilities to produce all varieties of organic products due to its diverse agro-climatic condition. This research aimed to identify the economics and efficiency of organic farming, and the possibilities to reduce farmers’ suicides in the Tamil Nadu region through the organic agriculture concept. The emphasis was on farmers, producers, researchers, and marketers entering the sustainable economy through organic farming by reducing input cost and high profit in cultivation. A survey was conducted to gather data. One way analysis of variance (ANOVA) has been used to test the hypothesis regards the cost and profit of rice production. The results showed that there was a significant difference in profitability between organic and conventional farming methods. It is very transparent that organic farming is the leading concept of sustainable agricultural development with better organic manures that can improve soil fertility, better yield, less input cost and better return than conventional farming. The study suggests that by reducing the cost of cultivation and get a marginal return through organic farming method to poor and small scale farmers will reduce socio-economic problems such as farmers’ suicides in the future of Indian agriculture.

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Sustainable Sources from Aquatic Organisms for Cosmeceuticals Ingredients

Cosmetics ◽

10.3390/cosmetics8020048 ◽

2021 ◽

Vol 8 (2) ◽

pp. 48

Author(s):

Carmen G. Sotelo ◽

María Blanco ◽

Patricia Ramos ◽

José A. Vázquez ◽

Ricardo I. Perez-Martin

Keyword(s):

Social Issues ◽

Good Condition ◽

Aquatic Organisms ◽

The Body ◽

Fishing Activity ◽

Marine Biomass ◽

Cosmetic Industry ◽

Wide Range ◽

Long Life ◽

By Products

Long life expectancy of populations in the developing world together with some cultural and social issues has driven the need to pay special attention to health and physical appearance. Cosmeceuticals are gaining interest in the cosmetic industry as their uses fulfills a double purpose: the requirements of a cosmetic (clean, perfume, protect, change the appearance of the external parts of the body or keeping them in good condition) with a particular bioactivity function. The cosmetics industry, producing both cosmetics and cosmeceuticals, is currently facing numerous challenges to satisfy different attitudes of consumers (vegetarianism, veganism, cultural or religious concerns, health or safety reasons, eco-friendly process, etc.). A currently growing trend in the market is the interest in products of low environmental impact. Marine origin ingredients are increasingly being incorporated into cosmeceutical preparations because they are able to address several consumer requirements and also due to the wide range of bioactivities they present (antioxidant, whitening, anti-aging, etc.). Many companies claim “Marine” as a distinctive marketing signal; however, only a few indicate whether they use sustainable ingredient sources. Sustainable marine ingredients might be obtained using wild marine biomass through a sustainable extractive fishing activity; by adopting valorization strategies including the use of fish discards and fish by-products; and by sustainably farming and culturing marine organisms.

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