scholarly journals Effects of salinity changes on aquatic organisms in a multiple stressor context

2018 ◽  
Vol 374 (1764) ◽  
pp. 20180011 ◽  
Author(s):  
Josefa Velasco ◽  
Cayetano Gutiérrez-Cánovas ◽  
María Botella-Cruz ◽  
David Sánchez-Fernández ◽  
Paula Arribas ◽  
...  
Keyword(s):  
Aquatic Ecosystems ◽  
Synergistic Effects ◽  
Experimental Studies ◽  
Aquatic Organisms ◽  
Joint Effect ◽  
Freshwater Ecosystems ◽  
Ion Concentration ◽  
Joint Effects ◽  
Multiple Stressor ◽  
Meta Analyses

Under global change, the ion concentration of aquatic ecosystems is changing worldwide. Many freshwater ecosystems are being salinized by anthropogenic salt inputs, whereas many naturally saline ones are being diluted by agricultural drainages. This occurs concomitantly with changes in other stressors, which can result in additive, antagonistic or synergistic effects on organisms. We reviewed experimental studies that manipulated salinity and other abiotic stressors, on inland and transitional aquatic habitats, to (i) synthesize their main effects on organisms' performance, (ii) quantify the frequency of joint effect types across studies and (iii) determine the overall individual and joint effects and their variation among salinity–stressor pairs and organism groups using meta-analyses. Additive effects were slightly more frequent (54%) than non-additive ones (46%) across all the studies ( n = 105 responses). However, antagonistic effects were dominant for the stressor pair salinity and toxicants (44%, n = 43), transitional habitats (48%, n = 31) and vertebrates (71%, n = 21). Meta-analyses showed detrimental additive joint effects of salinity and other stressors on organism performance and a greater individual impact of salinity than the other stressors. These results were consistent across stressor pairs and organism types. These findings suggest that strategies to mitigate multiple stressor impacts on aquatic ecosystems should prioritize restoring natural salinity concentrations. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.

scholarly journals Calcium interacts with temperature to influence Daphnia movement rates

2016 ◽  
Vol 3 (12) ◽  
pp. 160537 ◽  
Author(s):  
Gustavo S. Betini ◽  
Jordan Roszell ◽  
Andreas Heyland ◽  
John M. Fryxell
Keyword(s):  
Water Chemistry ◽  
Calcium Concentration ◽  
Synergistic Effects ◽  
Thermal Conditions ◽  
Aquatic Organisms ◽  
Freshwater Ecosystems ◽  
Environmental Stressors ◽  
Ecosystem Dynamics ◽  
Movement Rates ◽  
Projected Changes

Predicting the ecological responses to climate change is particularly challenging, because organisms might be affected simultaneously by the synergistic effects of multiple environmental stressors. Global warming is often accompanied by declining calcium concentration in many freshwater ecosystems. Although there is growing evidence that these changes in water chemistry and thermal conditions can influence ecosystem dynamics, little information is currently available about how these synergistic environmental stressors could influence the behaviour of aquatic organisms. Here, we tested whether the combined effects of calcium and temperature affect movement parameters (average speed, mean turning frequency and mean-squared displacement) of the planktonic Daphnia magna , using a full factorial design and exposing Daphnia individuals to a range of realistic levels of temperature and calcium concentration. We found that movement increased with both temperature and calcium concentration, but temperature effects became considerably weaker when individuals were exposed to calcium levels close to survival limits documented for several Daphnia species, signalling a strong interaction effect. These results support the notion that changes in water chemistry might have as strong an effect as projected changes in temperature on movement rates of Daphnia , suggesting that even sublethal levels of calcium decline could have a considerable impact on the dynamics of freshwater ecosystems.

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

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.

IMPROVEMENT OF THE METHOD FOR ASSESSMENT OF THE HETEROTROPHIC ACTIVITY OF FRESHWATER BACTERIA BY STUDYING HOW BACTERIAL COMMUNITY CONSUMES THE ORGANIC MATTER EXCRETED BY ALGAE: ISSUES OF WATER QUALITY

Fisheries ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. 61-66 ◽  
Author(s):  
Anatoly Sadchikov
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Aquatic Ecosystems ◽  
Aquatic Organisms ◽  
Freshwater Ecosystems ◽  
Trophic Levels ◽  
Organic Substances ◽  
Heterotrophic Activity ◽  
Freshwater Bacteria ◽  
Methods And Techniques

The article describes an improved and approved methodology for assessing the heterotrophic activity of freshwater bacteria using a specific example. Namely, the example of studying the bacterial consumption of organic matter excreted by algae. Utilization of organic substances in water bodies by microorganisms and their oxidation are an important part of the functioning of aquatic ecosystems and water self-purification. This article details innovative modifications to the method based on the use of 14C-labeled organic matter by aquatic organisms. All these methods and techniques have been tested in the study of production and destruction processes in freshwater ecosystems of different trophic levels including mesotrophic, eutrophic and hypertrophic surface ecosystems.

Protecting and Restoring Aquatic Ecosystems in Multiple Stressor Environments

2017 ◽  
Vol 03 (02) ◽  
pp. 1650011 ◽  
Author(s):  
Ram Ranjan ◽  
James Shortle
Keyword(s):  
Invasive Species ◽  
Aquatic Ecosystems ◽  
Synergistic Effects ◽  
Pollution Abatement ◽  
Native Fish ◽  
Fish Stock ◽  
Optimal Management ◽  
Invasion Risk ◽  
Multiple Stressor ◽  
Policy Measures

Aquatic ecosystems around the globe are under threat from pollution, invasive species, over-exploitation, and other stressors. Given synergistic effects, policy measures to address particular stressors should be developed in tandem with policy measures to address others. We present a bio-economic model that addresses the optimal management of an aquatic ecosystem subject to multiple stressors. Specifically, we consider optimal management of a native fishery in a lake ecosystem subject to risks from pollution and an invasive species. Optimal plans exist for various cases defined by whether, one, both, or neither of the stressor events has occurred. Optimal fishery stocks vary between these cases, and depend on the order in which the stressor event occur if realized. The optimal native stock is the highest in the absence of either stressor. However, the combined influence of the multiple risks can rapidly reduce the probability of maintaining an un-invaded and un-polluted state for long. The synergistic effects of the risks interconnect optimal policies in interesting ways. We find that optimal pollution abatement in absence of both these stressors may turn out to be lower than when either or both stressors are present. The effectiveness of native fish stock in mitigating the risk of alien fish invasion can have a bearing on whether optimal native fish stock and abatement effort are used as substitutes or as complements. Pollution abatement levels that are chosen without consideration of alien invasion risk can lead indirectly to increased societal costs for invasion risk mitigation.

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

Water ◽  
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.

scholarly journals Between Level Up and Game Over: A Systematic Literature Review of Gamification in Education

2021 ◽  
Vol 13 (4) ◽  
pp. 2247 ◽  
Author(s):  
Ana Manzano-León ◽  
Pablo Camacho-Lazarraga ◽  
Miguel A. Guerrero ◽  
Laura Guerrero-Puerta ◽  
José M. Aguilar-Parra ◽  
...  
Keyword(s):  
Systematic Review ◽  
Academic Performance ◽  
Game Design ◽  
Learning Strategy ◽  
Experimental Studies ◽  
Quasi Experimental ◽  
Current Lines ◽  
Meta Analyses ◽  
Game Elements ◽  
The Impact

Educational gamification consists of the use of game elements and game design techniques in the educational context. The objective of this study is to examine the existing evidence on the impact of educational gamification on student motivation and academic performance in the last five years in order to analyze its distribution over time, educational level, variables, and most used game elements, and know the advantages of its implementation in the classroom. For this, a systematic review is proposed through the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) methodology in three multidisciplinary databases, through an exhaustive search with inclusion and exclusion criteria on quantitative experimental studies that explore gamification in educational centers, which provide information about the most current lines of research. Fourteen studies were included in this review. These used experimental or quasi-experimental designs. Most of them report gamification as a valid learning strategy. The results support the conclusion that educational gamification has a potential impact on the academic performance, commitment, and motivation of students. Therefore, this study implies the need to expand research on the needs and challenges of students when learning with gamified techniques.

scholarly journals Influence of Coronal Preflaring on the Accuracy of Electronic Working Length Determination: Systematic Review and Meta-Analysis

2021 ◽  
Vol 10 (13) ◽  
pp. 2760
Author(s):  
María León-López ◽  
Daniel Cabanillas-Balsera ◽  
Victoria Areal-Quecuty ◽  
Jenifer Martín-González ◽  
María C. Jiménez-Sánchez ◽  
...  
Keyword(s):  
Systematic Review ◽  
Science Studies ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Risk Of Bias ◽  
Permanent Teeth ◽  
Total Risk ◽  
Human Teeth ◽  
Working Length ◽  
Meta Analyses

Aim. To conduct a systematic review and meta-analysis according to the following PICO question: in extracted human permanent teeth, does preflaring, compared with unflared canals, influence the accuracy of WL determination with EAL? Material and Methods. A systematic review was conducted according to the PRISMA checklist, using the following databases: PubMed, Science Direct, Scopus, and Web of Science. Studies related to WL determination using EAL both in preflared and unflared root canals of extracted human teeth were included. The outcome of interest was the accuracy of the electronic WL determination. A quality assessment of the included studies was performed, determining the risk of bias. The meta-analyses were calculated with the 5.4 RevMan software using the inverse variance method with random effects. PROSPERO registration: CRD42021243412. Results. Ten experimental studies fulfilled the inclusion criteria, and most of them found that preflaring increases the accuracy of the EALs in WL determination. The calculated OR was 1.98 (95% CI = 1.65–2.37; p < 0.00001; I2 = 10%), indicating that the determination of WL by EALs is almost twice as accurate in preflared canals. The accuracy of Root ZX in WL determination increases more than three times (OR = 3.25; p < 0.00001). Preflaring with Protaper files significantly increases the accuracy of EALs (OR = 1.76; p < 0.00001). The total risk of bias of the included studies was low. No obvious publication bias was observed. Conclusions. The results indicate a significant increase in the accuracy of WL determination with EAL after preflaring, doubling the percentage of exact measurements. Preflaring should be recommended as an important step during mechanical enlargement of the root canal, not only because it improves the access of the files to the canal, but also because it allows one to obtain more accurate electronic determinations of WL.

The Effect of Plantago major on Wound Healing in Preclinical Studies: A Systematic Review

2021 ◽  
Vol 67 (1) ◽  
pp. 27-34
Author(s):  
Fernanda Cardoso ◽  
Jéssica Breder ◽  
Priscila Apolinário ◽  
Henrique Oliveia ◽  
Maria Saidel ◽  
...  
Keyword(s):  
Systematic Review ◽  
Wound Healing ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Risk Of Bias ◽  
Preclinical Studies ◽  
Plantago Major ◽  
Best Response ◽  
Meta Analyses

BACKGROUND: Plantago major is a medicinal plant that has been used for centuries to treat various health conditions including wounds. PURPOSE: To investigate the effectiveness of the topical use of P major in healing skin wounds in animal models. METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review was conducted. Seven (7) electronic databases (Virtual Health Library, Public/Publisher MEDLINE, Scopus, Web of Science, Embase, Cumulative Index of Nursing and Allied Health Literature, and CAB Direct) were searched for controlled studies published in English from January 2006 to March 2020. The Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Studies tools guided the evaluation of the studies and determined their quality. The Systematic Review Center for Laboratory Animal Experimentation was used to assess the risk of bias. RESULTS: Of the 176 publications identified, 4 met the inclusion criteria. Studies included 20 to 100 animals and varying concentrations of P major. There were no reports of losses during research. Wound healing was assessed between 17 and 21 days following wounding. The best response in terms of wound contraction rate occurred with 10%, 20%, and 50% concentrations when compared with control groups. One (1) study did not have an animal ethics committee review. All studies had a high risk of bias and a lack of methodological rigor. CONCLUSION: The results of this review did not find evidence about the in vivo effectiveness of P major for wound healing. More rigorous preclinical studies with adequate sample sizes are required to identify the best concentrations and formulations as well as increase understanding about the mechanisms of action of P major in wound healing.

scholarly journals Potential impacts to freshwater ecosystems caused by flow regime alteration under changing climate conditions in Taiwan

2008 ◽  
Vol 5 (6) ◽  
pp. 3005-3032 ◽  
Author(s):  
J.-P. Suen
Keyword(s):  
Climate Change ◽  
Flow Regime ◽  
River Flow ◽  
Aquatic Organisms ◽  
Freshwater Ecosystems ◽  
Climate Conditions ◽  
Regime Changes ◽  
Changing Climate ◽  
Extreme Flood ◽  
Precautionary Measures

Abstract. Observed increases in the Earth's surface temperature bring with them associated changes in precipitation and atmospheric moisture that consequentially alter river flow regimes. This paper uses the Indicators of Hydrologic Alteration approach to examine climate-induced flow regime changes that can potentially affect freshwater ecosystems. Analyses of the annual extreme water conditions at 23 gauging stations throughout Taiwan reveal large alterations in recent years; extreme flood and drought events were more frequent in the period after 1991 than from 1961–1990, and the frequency and duration of the flood and drought events also show high fluctuation. Climate change forecasts suggest that such flow regime alterations are going to continue into the foreseeable future. Aquatic organisms not only feel the effects of anthropogenic damage to river systems, but they also face on-going threats of thermal and flow regime alterations associated with climate change. This paper calls attention to the issue, so that water resources managers can take precautionary measures that reduce the cumulative effects from anthropogenic influence and changing climate conditions.

scholarly journals FAKTOR-FAKTOR YANG MEMPENGARUHI TOKSISITAS BAHAN PENCEMAR TERHADAP ORGANISME PERAIRAN

OSEANA ◽  
2019 ◽  
Vol 42 (2) ◽  
pp. 12-22
Author(s):  
Triyoni Purbonegoro
Keyword(s):  
Environmental Factors ◽  
Physicochemical Properties ◽  
Aquatic Environment ◽  
Aquatic Ecosystems ◽  
Physiological Condition ◽  
Aquatic Organisms ◽  
Combined Effects ◽  
Biological Factors ◽  
Factors Affecting ◽  
Major Factors

FACTORS THAT AFFECTING THE TOXICITY OF POLLUTANTS TO AQUATIC ORGANISMS. There are a large number of pollutants in aquatic environment with various characteristics and factors that can modify and affect the toxicity of pollutants in this environment. The major factors affecting pollutant toxicity include physicochemical properties of pollutants, mode of exposure, time, environmental factors, and biological factors. Moreover, organisms in an aquatic ecosystem are seldom exposed to only single pollutant, and most cases the stress of pollution on aquatic ecosystems is related to the interaction and combined effects of many chemicals. The combined effects may be synergistic or antagonistic, depending on the pollutants and the physiological condition of the organism involved.

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