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A Furuhama, T I Hayashi, N Tatarazako
We constructed models for acute to chronic estimation of the Daphnia magna reproductive toxicities of chemical substances from their Daphnia magna acute immobilization toxicities. The models combined the acute toxicities with structural and physicochemical descriptors. We used multiregression analysis and selected the descriptors for the models by means of a genetic algorithm. Of the best 100 models (as indicated by the lack of fit score), 90% included the following descriptors: acute toxicity (i.e. an activity parameter), distribution coefficient (log D) and structural indicator variables that indicate the presence of -NH2 attached to aromatic carbon and the presence of a chlorine atom...
October 21, 2016: SAR and QSAR in Environmental Research
D Spasiano, A Siciliano, M Race, R Marotta, M Guida, R Andreozzi, F Pirozzi
Imidazole-based compounds are used as reagents for the manufacturing of other compounds including imidazolium-based ionic liquids, which have been recently proposed as a green alternative to conventional solvents. Since some imidazole-based compounds have been demonstrated to be harmful to aquatic organisms, the removal of imidazole, 1-methylimidazole, 1-ethyl-3-methyl-imidazolium chloride and 1-butyl-3-methyl-imidazolium chloride from aqueous solutions was attempted by biological oxidation, direct UV254 photolysis, and UV254/H2O2 process at pH 5...
October 11, 2016: Water Research
A C Rietzler, C R Botta, M M Ribeiro, O Rocha, A L Fonseca
The aim of this study was to jointly show the results of three independent ecotoxicological studies performed to investigate pollutants in three Brazilian tropical reservoirs undergoing accelerated eutrophication. In order to accomplish this goal, the full toxicity identification and evaluation procedure (TIE approach) was performed, at Pampulha (Minas Gerais State) and Salto Grande and Barra Bonita reservoirs (São Paulo State). Acute and chronic toxicity tests were performed using the cladocerans Daphnia similis and Ceriodaphnia dubia (exotic) and Daphnia laevis and Ceriodaphnia silvestrii (native) as test organisms...
October 19, 2016: Environmental Science and Pollution Research International
Silvia Echeverría-Sáenz, Freylan Mena, María Arias-Andrés, Seiling Vargas, Clemens Ruepert, Paul J Van den Brink, Luisa E Castillo, Jonas S Gunnarsson
The River Madre de Dios (RMD) and its lagoon is a biodiversity rich watershed formed by a system of streams, rivers, channels, and a coastal lagoon communicating with the Caribbean Sea. This basin sustains a large area of agricultural activity (mostly banana, rice, and pineapple) with intensive use of pesticides, continually detected in water samples. We investigated in situ the toxicological effects caused by pesticide runoff from agriculture and the relation of pesticide concentrations with different biological organization levels: early responses in fish biomarkers (sub-organismal), acute toxicity to Daphnia magna (organismal), and aquatic macroinvertebrate community structure...
October 18, 2016: Environmental Science and Pollution Research International
Martin May, Wiebke Drost, Sabine Germer, Tanja Juffernholz, Stefan Hahn
BACKGROUND: Acute-to-chronic extrapolation is an important approach to predict acceptable no-effect levels from acute data which has some uncertainties, but is valuable for risk assessment of chemical substances. With regard to the still limited and heterogenic data of chronic fish tests, conclusions on aquatic hazard estimation need to be checked and the question arises whether the chronic toxicity to fish can be adequately derived from acute data. A comprehensive dataset including ecotoxicological studies of 203 substances was used to investigate acute-to-chronic ratios (ACR) for both fish and Daphnia...
2016: Environmental Sciences Europe
Jeong-Ann Park, Song-Bae Kim
Antimicrobial electrospun poly(vinyl alcohol) (PVA) nanofibers were synthesized by impregnating benzyl triethylammonium chloride (BTEAC) as an antimicrobial agent into PVA nanofibers. The BTEAC-PVA nanofibers were heat-methanol treated during the preparation for various tests. The BTEAC-PVA nanofibers became more hydrophilic than the PVA nanofibers due to incorporation of BTEAC. Through heat-methanol treatment, thermal property, crystallinity, and water stability of BTEAC-PVA nanofibers were improved considerably...
October 14, 2016: Chemosphere
A Rodríguez-Seijo, A Cachada, A Gavina, A C Duarte, F A Vega, M L Andrade, R Pereira
Soil pollution at firing ranges is an issue of growing importance, due to the accumulation in soils of contaminants derived from ammunition and clay targets. The concentration of Pb and PAHs was determined in five soils of an abandoned shooting range in Galicia (northwest Spain), and an ecotoxicological characterization was performed in order to obtain an assessment of risks. Therefore, the retention capacity of soils was assessed using test organisms of different trophic levels, and the role of soils as habitat for soil invertebrates was assessed by reproduction tests and bioaccumulation assays with earthworms...
October 13, 2016: Science of the Total Environment
Marinela Dukić, Daniel Berner, Marius Roesti, Christoph R Haag, Dieter Ebert
BACKGROUND: Recombination rate is an essential parameter for many genetic analyses. Recombination rates are highly variable across species, populations, individuals and different genomic regions. Due to the profound influence that recombination can have on intraspecific diversity and interspecific divergence, characterization of recombination rate variation emerges as a key resource for population genomic studies and emphasises the importance of high-density genetic maps as tools for studying genome biology...
October 13, 2016: BMC Genetics
Ramsy Agha, Manja Saebelfeld, Christin Manthey, Thomas Rohrlack, Justyna Wolinska
Parasites are rarely included in food web studies, although they can strongly alter trophic interactions. In aquatic ecosystems, poorly grazed cyanobacteria often dominate phytoplankton communities, leading to the decoupling of primary and secondary production. Here, we addressed the interface between predator-prey and host-parasite interactions by conducting a life-table experiment, in which four Daphnia galeata genotypes were maintained on quantitatively comparable diets consisting of healthy cyanobacteria or cyanobacteria infected by a fungal (chytrid) parasite...
October 13, 2016: Scientific Reports
Donat-P Häder, Gilmar S Erzinger
The microcrustacean Daphnia is sensitive to many toxic substances and can be cultured easily. The Daphniatox instrument is based on computerized image analysis tracking swimming organisms in real time. The software evaluates 14 endpoints including motility, swimming velocity, orientation with respect to light and gravity as well as cell form and size. The system determines movement vectors of a large number of organisms to warrant high statistical significance and calculates mean values as well as standard deviation...
October 7, 2016: Chemosphere
Freya E Rowland, Madelyn B Rawlings, Raymond D Semlitsch
Primary production can be controlled through bottom-up (e.g., resources) or top-down (e.g., predators) constraints. Two key bottom-up resources in small aquatic systems are light and nutrients, and forest canopy cover heavily influences these factors, whereas amphibian and invertebrate colonizers exert top-down pressure as grazers and predators. We designed our experiment to specifically manipulate two different top-down and bottom-up factors. We manipulated resources by altering light (low/high) and nutrient (low/high) availability; omnivores with the presence/absence of southern leopard frog tadpoles (Lithobates sphenocephalus); and predators with the presence/absence of spotted salamander larvae (Ambystoma maculatum) in a full-factorial experiment conducted over 14 weeks...
October 7, 2016: Oecologia
Ying Zhang, Jing Ma, Liu Shi, Di Cao, Xie Quan
Information on joint toxicity is limited. To clarify the joint toxicity and the interactions among toxicants on different aquatic organisms, we investigated the acute toxicity of cadmium and sodium dodecyl benzene sulfonate, two chemicals with high concerns in Chinese waters, on the immobilization of Daphnia magna (D. magna) and the swimming behavior of Danio rerio (D. rerio). Our results illustrated that cadmium and sodium dodecyl benzene sulfonate expressed a synergistic effect on the immobilization of D...
October 5, 2016: Ecotoxicology
Nadine V Gerner, Macoura Koné, Matthew S Ross, Alberto Pereira, Ania C Ulrich, Jonathan W Martin, Matthias Liess
In Canada, the Athabasca oil sands deposits are a source of bitumen-derived contaminants, reaching the aquatic environment via various natural and anthropogenic pathways. The ecological effects of these contaminants are under debate. To quantify the effects of bitumen-derived contaminants we monitored the aquatic exposure of polycyclic aromatic hydrocarbons (PAHs), metals, and naphthenic acids as well as the invertebrate community in the Athabasca River and its tributaries. PAH concentrations over 3 consecutive years were related to discharge and were highest in the year with high autumn rainfall...
October 1, 2016: Science of the Total Environment
Cunman Yang, Ying Li, Daoping Zha, Guanghua Lu, Qin Sun, Donghai Wu
A modified polar organic chemical integrative sampler (m-POCIS) was used to determine the occurrence of and risk posed by organophosphate flame retardants (OPFRs) in the Yangtze River in Nanjing. Laboratory calibrations were performed to determine sampling rates (Rs) in different situations. Rs values increased with the flow rate, but the effect of dissolved organic matter (DOM) on Rs was relatively small. The validation of Rs in the m-POCIS for 15 days at the Yangtze River in 2015 showed that the Rs values for most of the test compounds are considerably larger than those obtained in the laboratory...
October 2, 2016: Chemosphere
You Song, Jan Thomas Rundberget, Linn Mari Evenseth, Li Xie, Tânia Gomes, Tore Høgåsen, Taisen Iguchi, Knut Erik Tollefsen
Emamectin benzoate (EMB) is an anti-sea lice chemical widely used in the aquaculture that may also unintentionally affect non-target crustaceans in the environment. Although the adverse effects of this compound are well documented in various species, the full modes of action (MoAs) are still not well characterized. The current study was therefore conducted to characterize the MoAs of EMB and link perturbations of key toxicological pathways to adverse effects in the model freshwater crustacean Daphnia magna...
October 5, 2016: Environmental Science & Technology
Soledad Chamorro, Daniela López, Pablina Brito, Mayra Jarpa, Benjamin Piña, Gladys Vidal
The implementation of elemental chlorine-free (ECF) bleaching methods has drastically reduced the aquatic toxicity of Kraft mill effluents during the last decade. However, the residual toxicity of Kraft mill effluents is still a potential concern for the environment, even when subjected to secondary wastewater treatment. The aim of this study is characterize potential sublethal effects of ECF Kraft mill effluents using Daphnia magna as model species. D. magna exposed towards increasing concentration of ECF Kraft mill effluent showed a significant, dose-dependent reduction in feeding...
October 4, 2016: Bulletin of Environmental Contamination and Toxicology
G Lofrano, G Libralato, M Carotenuto, M Guida, M Inglese, A Siciliano, S Meriç
Textile dyes and their residues gained growing attention worldwide. Textile industry is a strong water consumer potentially releasing xenobiotics from washing and rinsing procedures during finishing processes. On a decentralised basis, also final consumers generate textile waste streams. Thus, a procedure simulating home washing with tap water screened cotton textiles leachates (n = 28) considering physico-chemical (COD, BOD5, and UV absorbance) and ecotoxicological data (Daphnia magna, Pseudokirchneriella subcapitata and Lepidium sativum)...
October 4, 2016: Bulletin of Environmental Contamination and Toxicology
Florian Zindler, Berit Glomstad, Dag Altin, Jing-Fu Liu, Bjorn M Jenssen, Andy M Booth
Studies investigating the effect of carbon nanotubes (CNTs) on the bioavailability and toxicity of hydrophobic organic compounds in aquatic environments have generated contradictory results, and the influence of different CNT properties remains unknown. Here, the adsorption of the polycyclic aromatic hydrocarbon phenanthrene (70-735 µg/L) to five types of CNTs exhibiting different physical and chemical properties was studied. The CNTs were dispersed in the presence of natural organic matter (nominally 20 mg/L) in order to increase the environmental relevance of the study...
October 4, 2016: Environmental Science & Technology
Savvas J Constantinou, Ryan M Pace, A J Stangl, Lisa M Nagy, Terri A Williams
Wnt genes are a family of conserved glycoprotein ligands that play a role in a wide variety of cell and developmental processes, from cell proliferation to axis elongation. There are 13 Wnt subfamilies found among metazoans. Eleven of these appear conserved in arthropods with a pattern of loss during evolution of as many as six subfamilies among hexapods. Here we report on Wnt genes in the branchiopod crustacean, Thamnocephalus platyurus, including the first documentation of the expression of the complete Wnt gene family in a crustacean...
October 3, 2016: Evolution & Development
Ang Li, Qian-Yuan Wu, Gui-Peng Tian, Hong-Ying Hu
Methylisothiazolone (MIT) is a common biocide that is widely used in water-desalination reverse-osmosis processes. The transformation of MIT during water treatment processes is poorly understood. The kinetics and mechanisms involved in the degradation of MIT during ozonation were investigated in this study. Ozonation was found to be a useful way of degrading MIT in water, and the degradation rate constant was 0.11 (±0.1) × 10(3) L/(mol·s). The degradation rate constant did not change when the pH was increased from 3 to 9...
December 1, 2016: Journal of Environmental Management
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