| algicidal activity of phthalocyanines--screening of 31 compounds. | phthalocyanines and their analogues show great potential as photodynamic agents producing reactive oxygen species (ros), especially in medicine. however, their biocidal effects may also be employed to inhibit various undesirable organisms. this study explores their potential algicidal effects. the laboratory tests concern the effects of various phthalocyanine derivatives on the green alga pseudokirchneriella subcapitata and cyanobacterium synechococcus nidulans. their effects on one example of t ... | 2008 | 18214913 |
| ecotoxicity of quinoline and hydroxylated derivatives and their occurrence in groundwater of a tar-contaminated field site. | in the groundwater of a timber impregnation site higher concentrations of hydroxylated quinolines compared to their parent compounds quinoline and isoquinoline were found. studying the toxicity of parent compounds and metabolites, genotoxicity was found with metabolic activation in the sos-chromotest and ames fluctuation test only for quinoline. an adverse effect on algae was observed only for the parent compounds quinoline and isoquinoline, while in the daphnia magna immobilization assay most h ... | 2009 | 18550163 |
| host-parasite coevolution: insights from the daphnia-parasite model system. | daphnia and its parasites have become recognized as a model system for studying the epidemiological, evolutionary and genetic interactions between hosts and parasites. the key advantages of the daphnia-parasite system are the propagation of the host as iso-female lines, that is clonal, but at the same time the possibility to cross lines. furthermore, daphnia have diverse parasites, including bacteria, fungi, microsporidia and helminths, which can be kept in culture with the hosts. for two parasi ... | 2008 | 18556238 |
| temperature-dependent costs of parasitism and maintenance of polymorphism under genotype-by-environment interactions. | the maintenance of genetic variation for infection-related traits is often attributed to coevolution between hosts and parasites, but it can also be maintained by environmental variation if the relative fitness of different genotypes changes with environmental variation. to gain insight into how infection-related traits are sensitive to environmental variation, we exposed a single host genotype of the freshwater crustacean daphnia magna to four parasite isolates (which we assume to represent dif ... | 2008 | 18557795 |
| a comparison of the response of simocephalus mixtus (cladocera) and daphnia magna to contaminated freshwater sediments. | the southeast region of mexico is characterized by intensive oil industry activities carried out by the national public enterprise petróleos mexicanos (pemex). the freshwater lagoon "el limón", located in the municipality of macuspana, state of tabasco, mexico, has received over 40 years discharges of untreated waste waters from the petrochemical complex "ciudad pemex", located on the border of the lagoon. to assess the toxicity of the sediments and, hence, to obtain information on the biologica ... | 2008 | 18573528 |
| bacterial infection changes the elemental composition of daphnia magna. | 1. an animal's elemental composition can be an important indicator of its physiological state and role in ecosystem nutrient cycling. we examined the interactive effects of bacterial (pasteuria ramosa) infection and phosphorus (p)-poor food on the body stoichiometry of daphnia magna. daphnia were exposed to or held free of a bacterial parasite and fed algal food of different c:p ratios (100-500) over a 28-day period. 2. to assess the effects of exposure and infection on daphnia stoichiometry, we ... | 2008 | 18631369 |
| biodegradation and detoxication of phenol by using free and immobilized cells of acinetobacter sp. xa05 and sphingomonas sp. fg03. | strain xa05 and fg03 with high biodegradation activity of phenol were isolated from the activated sludge and phenol-contaminated soils in northwest of china, respectively. dna sequencing and homologous analysis of 16s rrna gene identified that xa05 belonged to an acinetobacter sp. and fg03 was closely related to the sphingomonas sp. cells of strain xa05 and fg03 were mixed at the ratio of 1:1, and polyvinyl alcohol (pva) was used as a gel matrix to immobilize mixed cells by repeated freezing and ... | 2009 | 19123092 |
| comparison of different treatment strategies for industrial landfill leachate. | the aim of our research was to determine appropriate treatment technique for effective treatment of heavily polluted tannery landfill leachate. we have accomplished several treatment experiments: (i) aerobic biological treatment, (ii) air stripping at various ph, (iii) adsorption to activated carbon, (iv) coagulation-flocculation and (v) advanced oxidation process with fe(2+)/h(2)o(2). efficiency of each procedure was monitored by chemical analysis and changes in biodegradability and acute toxic ... | 2009 | 18650010 |
| effect of temperature on imidacloprid oxidation by homogeneous photo-fenton processes. | this paper presents experimental results on the effect of temperature on the rate of imidacloprid removal from waste water using homogeneous photo-fenton processes. experiments were conducted in a 2 l photo reactor set at 15-42 degrees c, initial concentrations in the range of 10 to 40 mg l(-1) fe(ii) and 100-450 mg l(-1) h(2)o(2); 30 150 min processing times. initial h(2)o(2) concentration determined the extent of the oxidation process, whereas iron concentration played a key role in the proces ... | 2008 | 18653963 |
| comparison of a test battery for assessing the toxicity of a bleached-kraft pulp mill effluent before and after secondary treatment implementation. | pulp and paper mill effluents may cause harmful effects to the aquatic environment due to the combined influence of physical factors, toxic compounds, and nutrient enrichment. in the present study, the effectiveness of secondary treatment in reducing the toxicity of an elemental chlorine-free bleached-kraft pulp mill effluent was evaluated. to characterize the toxicity of the effluent, before and after the implementation of secondary treatment, a battery of tests with organisms bearing different ... | 2010 | 19242815 |
| fluoxetine effects assessment on the life cycle of aquatic invertebrates. | fluoxetine is a serotonin re-uptake inhibitor, generally used as an antidepressant. it is suspected to provoke substantial effects in the aquatic environment. this study reports the effects of fluoxetine on the life cycle of four invertebrate species, daphnia magna, hyalella azteca and the snail potamopyrgus antipodarum exposed to fluoxetine spiked-water and the midge chironomus riparius exposed to fluoxetine-spiked sediments. for d. magna, a multi-generational study was performed with expositio ... | 2008 | 18656226 |
| toxicity assessment of organic pollutants: reliability of bioluminescence inhibition assay and univariate qsar models using freshly prepared vibrio fischeri. | the toxicity of 14 industrially relevant organic chemicals was determined using freshly grown vibrio fischeri bioluminescence inhibition assay. the results were compared to lyophilized v. fischeri, 96h fish, 48h daphnia magna and 95h green algae bioassays. reliability of octanol-water partition coefficient (k(ow)), and first order simple and valence molecular connectivity index ((1)chi, (1)chi(v)) based regression models for predicting toxicity to v. fischeri was studied. correlations were obtai ... | 2008 | 18701087 |
| ista13--international interlaboratory comparative evaluation of microbial assay for risk assessment (mara). | the microbial assay for risk assessment (mara) is an innovative system based on an array of 11 different microbial species freeze-dried in a 96-well micro-titer plate. developed for testing the toxicity of chemicals, mixtures, and environmental samples, the assay employs species of a taxonomically diverse range. in addition to 10 prokaryotic species, a eukaryote (yeast) is included in the range. the mara's innate scope of a multi-dimensional test allows determination of toxicity based on a uniqu ... | 2008 | 18712790 |
| fate and effects of amphoteric surfactants in the aquatic environment. | amphoteric surfactants form part of specialty surfactants available for formulators to improve or design new formulations in response to environmental, toxicity, safety and performance demands. nevertheless, limited information on the ecological properties of amphoterics is available. in the present work, the aerobic and anaerobic biodegradability and the aquatic toxicity of different types of amphoteric surfactants (three alkyl betaines, one alkylamido betaine and three alkyl imidazoline deriva ... | 2008 | 18456334 |
| ecotoxicological assessment of water and sediment of the corumbataí river, sp, brazil. | the corumbataí river drains an economically important area which is mainly represented by the municipalities of piracicaba and rio claro. in view of the impacts caused by the discharge of industrial waste and domestic sewage into the piracicaba river, the corumbataí has become increasingly significant as a source of water for the municipality of piracicaba. however, chemical, physical, and microbiological analyses carried out prior to the present study had already indicated a decline in the qual ... | 2008 | 18470378 |
| an assessment of the potential toxicity of runoff from an urban roadscape during rain events. | the potential negative impact of urban storm water on aquatic freshwater ecosystems has been demonstrated in various studies with different types of biological methods. there are a number of factors that influence the amount and bioavailability of contaminants in storm water even if it is derived from an area with a fairly homogenous land use such as a roadscape where a variation in toxicity during rain events might be expected. there are only a few previous investigations on the toxicity of hig ... | 2008 | 18504838 |
| assessment of chemical, biochemical and ecotoxicological aspects in a mine soil amended with sludge of either urban or industrial origin. | a greenhouse pot experiment was conducted to evaluate the effect of sewage sludge (ss), of sugar beet sludge (sbs), or of a combination of both, in the remediation of a highly acidic (ph 3.6) metal-contaminated soil, affected by mining activities. the ss was applied at 100 and 200 mg ha(-1) (dry weight basis), and the sbs at 7 mg ha(-1). all pots were sown with italian ryegrass (lolium multiflorum lam.). after 60 d of growth, shoot biomass was quantified and analysed for cu, pb and zn. the pseud ... | 2008 | 18547605 |
| acute toxicity of parabens and their chlorinated by-products with daphnia magna and vibrio fischeri bioassays. | the acute toxicity of 21 parabens and their chlorinated derivatives was investigated by means of two toxicity bioassays: daphnia magna immobilization test and the inhibition of bioluminescence of vibrio fischeri. the median effective concentration (ec(50)) values of the tested parabens ranged from 2.2 to 62 mg l(-1) in the d. magna test and from 0.0038 to 5.9 mg l(-1) in the v. fischeri test at 15 min after exposure. the toxicity of dichlorinated methyl- and n-propylparaben, the most commonly us ... | 2009 | 19089854 |
| organic residues as immobilizing agents in aided phytostabilization: (ii) effects on soil biochemical and ecotoxicological characteristics. | sewage sludge (ss), municipal solid waste compost, and garden waste compost (gwc) were used as immobilizing agents in aided phytostabilization of an acid metal-contaminated soil affected by mining activities. the organic residues were applied at 25, 50 and 100 mg ha(-1) (dry weight basis) and perennial ryegrass (lolium perenne l.) was used as a "green cover". we studied the effects of the treatments on soil phytotoxicity and enzymatic activities, and on the composition and toxicity of the soil l ... | 2009 | 19091381 |
| comparative metagenomics of daphnia symbionts. | shotgun sequences of dna extracts from whole organisms allow a comprehensive assessment of possible symbionts. the current project makes use of four shotgun datasets from three species of the planktonic freshwater crustaceans daphnia: one dataset from clones of d. pulex and d. pulicaria and two datasets from one clone of d. magna. we analyzed these datasets with three aims: first, we search for bacterial symbionts, which are present in all three species. second, we search for evidence for cyanob ... | 2009 | 19383155 |
| prophenoloxidase in daphnia magna: cdna sequencing and expression in relation to resistance to pathogens. | invertebrates utilise the innate immune system when defending against pathogenic attack. however, except for some effectors as prophenoloxidase (propo), the innate immune response is less well understood outside model insect species, and its role in natural host-pathogen systems is generally not well documented. we have therefore initiated studies on the immune response of the crustacean daphnia when exposed to the specialist endobacterial pathogen, pasteuria ramosa. this study was focused on th ... | 2009 | 19103220 |
| leachates from plastic consumer products--screening for toxicity with daphnia magna. | plastic products can contain chemicals that are hazardous to human health and the environment. in this study, it was investigated if various plastic products emit hazardous chemical substances to water. two leaching methods (batch and diffusion tests) were used and the leachates were tested for acute toxicity to daphnia magna. nine out of 32 tested plastic product leachates had daphnia 48-h ec(50)s ranging from 5 to 80 g plastic material l(-1). for the remaining 23 products no effect on mobility ... | 2009 | 19108869 |
| generation of endocrine disruptor compounds during ozone treatment of tannery wastewater confirmed by biological effect analysis and substance specific analysis. | ozone (o3) with its high oxidation potential was used to degrade or eliminate pollutants contained in tannery wastewater when applying different phs and quantities of o3. our objective was a chemical degradation by o3 to achieve an enhancement of biodegradability, with a parallel decrease in toxicity. conventional analyses and bioassays beside substance specific analyses were performed to clear-up the behaviour of wastewater content from tanning process. the results demonstrate that the dominant ... | 2009 | 19151483 |
| analyses of perch (perca fluviatilis) bile suggest increasing exposure to pahs and other pollutants in a reference area on the swedish baltic coast. | kvädöfjärden on the swedish baltic coast has been used as a reference station in the swedish national marine monitoring programme since 1988. during this time an increasing trend in ethoxyresorufin-o-deetylase (erod) activity and a decreasing trend in gonad size for female perch have been observed. it is known that erod activity respond to exposure to certain groups of pollutants, including polycyclic aromatic hydrocarbons (pahs). in the present study, perch bile from two years with high (2006) ... | 2009 | 19212598 |
| occurrence of dna methylation in daphnia magna and influence of multigeneration cd exposure. | most of the research on the epigenetic phenomenon of dna methylation has been performed with vertebrates and plants. knowledge on dna methylation in daphnia magna, a key test organism in aquatic toxicology, is completely lacking. through epigenetic inheritance, effects of transient chemical exposure could be transferred to non-exposed generations, which could have a major impact on ecological risk assessment procedures. in this study, we determined if cpg methylation occurs in d. magna and if th ... | 2009 | 19249097 |
| a whole sample toxicity assessment to evaluate the sub-lethal toxicity of water and sediment elutriates from a lake exposed to diffuse pollution. | the impact of diffuse pollution in aquatic systems is of great concern due to the difficult to measure and regulate it. as part of an ecological risk assessment (era), this study aims to use a whole sample toxicity assessment to evaluate the toxicity of water and sediment from lake vela, a lake that has been exposed to diffuse pollution. in this way, standard (algae: pseudokirchneriella subcapitata; cladoceran: daphnia magna) and local species (algae: aphanizomenon flos-aquae; cladoceran: daphni ... | 2009 | 18655178 |
| biochemical biomarkers in environmental studies--lessons learnt from enzymes catalase, glutathione s-transferase and cholinesterase in two crustacean species. | for reliable environmental risk assessment of pollutants, knowledge on the effects at different levels of biological organisation is needed. during the early days of biomarker research in environmental studies approximately two decades ago, biochemical biomarkers were considered as the most promising tool for such purposes. among these, three enzymes have often been studied: catalase (cat), glutathione s-transferase (gst) and cholinesterase (che). however, despite their intensive research, their ... | 2010 | 19259718 |
| weighing the evidence of ecological risk from pahs contamination in the estuarine environment of salina cruz bay, méxico. | results of bulk-phase chemical measurements, toxicological tests combined with bioaccumulation measures in fishes, were used to evaluate the toxicity of the 16 usepa priority polycyclic aromatic hydrocarbons from the sediment collected from eight stations of the ventosa estuarine system, located close to the main center of processing oil in the mexican pacific coast. levels of the sum of polycyclic aromatic hydrocarbons varied from 22 to 6,850 microg kg(-1) dry weight. based on sediment quality ... | 2010 | 19266302 |
| larvicidal activity of the water extract of moringa oleifera seeds against aedes aegypti and its toxicity upon laboratory animals. | in this work, biological effects of the water extract of moringa oleifera seeds (wemos) were assessed on eggs and 3rd instar larvae of aedes aegypti and on its toxicity upon laboratory animals (daphnia magna, mice and rats). crude wemos showed a lc50 value of 1260microg/ml, causing 99.2 +/- 2.9% larvae mortality within 24 h at 5200microg/ml, though this larvicidal activity has been lost completely at 80 masculinec/10 min. wemos did not demonstrate capacity to prevent egg hatching. after extensiv ... | 2009 | 19488625 |
| hazard identification of imidacloprid to aquatic environment. | the use of a very effective insecticide against sucking pests, neonicotinoid imidacloprid, has been increasing extensively. for this reason elevated concentrations are expected in aquatic environment. despite this fact, there is still a lack of data available on its possible risk for the environment. in this study, the potential hazards of imidacloprid and its commercial product confidor sl 200 to aquatic environment were identified by the acute and chronic toxicity assessment using bacteria vib ... | 2009 | 19505710 |
| the toxicity of sulfamethazine to daphnia magna and its additivity to other veterinary sulfonamides and trimethoprim. | sulfonamides (sas), the oldest chemotherapeutic agents used for antimicrobial therapy, still play an important role in veterinary mass treatments. consequently, traces of these compounds, alone or in combinations, have been repeatedly detected in the environment. sulfamethazine (smz) deserves particular attention not only because it is the most used veterinary sa, but also due to its proven effects on fertility in mice and on thyroid hormone homeostasis in rats. in this study, after evaluating t ... | 2009 | 19269673 |
| acute toxicity of atrazine, endosulfan sulphate and chlorpyrifos to vibrio fischeri, thamnocephalus platyurus and daphnia magna, relative to their concentrations in surface waters from the alentejo region of portugal. | ecotoxicological effects of the herbicide atrazine and the insecticides endosulfan sulphate and chlorpyrifos were evaluated using a test battery comprising aquatic organisms from different trophic levels. according to the categories established in the eu legislation, atrazine can be considered non-harmful for the species tested, while the insecticides can be considered very toxic for the crustaceans. the results of acute toxicity tests showed that the sensitivity of organisms were as follows: th ... | 2008 | 18777155 |
| c60 fullerene: a powerful antioxidant or a damaging agent? the importance of an in-depth material characterization prior to toxicity assays. | since the discovery of fullerenes in 1985, these carbon nanospheres have attracted attention regarding their physico/chemical properties. despite little knowledge about their impact on the environment and human health, the production of fullerenes has already reached an industrial scale. however, the toxicity of c(60) is still controversially discussed. the aim of this study was to clarify the biological effects of tetrahydrofuran (thf) suspended c(60) fullerene in comparison to water stirred c( ... | 2009 | 18824284 |
| molecular characterization of microbial population dynamics during sildenafil citrate degradation. | little is known about pharmaceutical and personal care products pollutants (ppcps), but there is a growing interest in how they might impact the environment and microbial communities. the widespread use of viagra (sildenafil citrate) has attracted great attention because of the high usage rate, the unpredictable disposal and the unknown potential effects on wildlife and the environment. until now information regarding the impact of viagra on microbial community in water environment has not been ... | 2009 | 18855147 |
| effects of the cyanobacterium cylindrospermopsis raciborskii on feeding and life-history characteristics of the grazer daphnia magna. | laboratory experiments were used to test the hypothesis that feeding and growth of the zooplankton grazer daphnia magna will decrease with increasing proportions of the cyanobacterium cylindrospermopsis raciborskii in the diet (mixed feeds with the green alga scenedesmus obliquus). a strain of c. raciborskii, which does not produce cylindrospermopsin but contains saxitoxins and gonyautoxins, was not acutely toxic to daphnia, as the daphnids survived slightly longer in suspensions with the cyanob ... | 2009 | 18951629 |
| biodegradability and toxicity of sulphonate-based surfactants in aerobic and anaerobic aquatic environments. | four types of commonly used sulphonate-based surfactants (alkane sulphonates, alpha-olefin sulphonates, sulphosuccinates and methyl ester sulphonates) were tested for their aerobic and anaerobic biodegradability as well as for their toxicity to daphnia magna and photobacterium phosphoreum to assess the effect of the surfactant structure on those properties. aerobic biodegradation was evaluated by means of the co2 headspace test and anaerobic biodegradation was assessed by a method based on the e ... | 2009 | 18976786 |
| effect of increasing nitrobenzene loading rates on the performance of anaerobic migrating blanket reactor and sequential anaerobic migrating blanket reactor/completely stirred tank reactor system. | a laboratory scale anaerobic migrating blanket reactor (ambr) reactor was operated at nitrobenzene (nb) loading rates increasing from 3.33 to 66.67 g nb/m(3)day and at a constant hydraulic retention time (hrt) of 6 days to observe the effects of increasing nb concentrations on chemical oxygen demand (cod), nb removal efficiencies, bicarbonate alkalinity, volatile fatty acid (vfa) accumulation and methane gas percentage. moreover, the effect of an aerobic completely stirred tank reactor (cstr) re ... | 2009 | 19286317 |
| experimental evolution of field populations of daphnia magna in response to parasite treatment. | although there is little doubt that hosts evolve to reduce parasite damage, little is known about the evolutionary time scale on which host populations may adapt under natural conditions. here we study the effects of selection by the microsporidian parasite octosporea bayeri on populations of daphnia magna. in a field study, we infected replicated populations of d. magna with the parasite, leaving control populations uninfected. after two summer seasons of experimental evolution (about 15 genera ... | 2008 | 18462312 |
| preparation, characterization of nipam and nipam/bam copolymer nanoparticles and their acute toxicity testing using an aquatic test battery. | poly n-isopropylacrylamide and n-isopropylacrylamide/n-tert-butylacrylamide copolymer nanoparticles of 50-70 nm were prepared by free radical polymerisation. the particle sizes of the copolymer nanoparticles were measured in the test media milli-q water, algae media, daphnia media and microtox diluent as a function of temperature. whereas in milli-q water the particle size was seen to decrease above the lower critical solution temperature of the thermoresponsive polymer, in the test media it was ... | 2009 | 19303150 |
| assessment of the environmental risk of long-chain aliphatic alcohols. | an environmental assessment of long-chain alcohols (lcoh) has recently been conducted under the oecd sids high production volume (hpv) program via the global international council of chemical associations (icca) aliphatic alcohols consortium. lcoh are used primarily as intermediates, as a precursor to alcohol-based surfactants and as alcohol per se in a wide variety of consumer product applications. global production volume is approximately 1.58 million metric tonnes. the oecd hpv assessment cov ... | 2009 | 19013645 |
| evaluation of wastewater reclamation technologies based on in vitro and in vivo bioassays. | when municipal secondary effluent is used as the main supplementation water source for surface water bodies, its potential adverse ecological effects should not be neglected. the objective of this work was to investigate the effectiveness of several technologies, i.e. combination of coagulation and sand filtration (csf), ultraviolet (uv) irradiation, chlorination, ozonation, ultrafiltration (uf) and reverse osmosis filtration (ro), on the removal of acute ecotoxicity, genotoxicity and retinoic a ... | 2009 | 19054546 |
| phototoxicity and oxidative stress responses in daphnia magna under exposure to sulfathiazole and environmental level ultraviolet b irradiation. | sulfonamide antibiotics frequently occur in aquatic environments. in this study, phototoxicity of sulfathiazole (stz) and its mechanism of action were investigated using daphnia magna. we evaluated the changes of molecular level stress responses by assessing gene expression, enzyme induction and lipid peroxidation, and the related organism-level effects in d. magna. in the presence of ultraviolet b (uv-b) light (continuous irradiation with 13.8+/-1.0microwcm(-2)d(-1)), stz (at the nominal concen ... | 2009 | 19054584 |
| an ecotoxicological study of poly(amidoamine) dendrimers-toward quantitative structure activity relationships. | polyamidoamine (pamam) dendrimers of generation 6-4, g-5 and g-6 were evaluated for their aquatic toxicity using the test models vibrio fischeri, daphnia magna, thamnocephalus platyurus, and two fish cell lines. physico-chemical characterization of the particles in each of the different test media was performed. a significant eco- and cytotoxicological response was recorded at concentrations from 0.129 microm (7.4 mg l(-1)) to 16.30 microm (231.5 mg l(-1)). daphnia magna was found to be the most ... | 2009 | 19764261 |
| chemical stabilization of medical waste fly ash using chelating agent and phosphates: heavy metals and ecotoxicity evaluation. | chemical stabilization of heavy metals in medical waste fly ash has been carried out using the following compounds: a chelating agent (ashnite s803), a commercial acidic phosphoric acid solution (ashnite r303) as well as basic one (ashnite r201). in order to predict the leachability of heavy metals, japanese leaching test (jlt-13) procedure was applied to the stabilized fly ash products. an ecotoxicity assessment of the stabilized fly ash products leachate and the unstabilized fly ash leachate w ... | 2009 | 19356916 |
| evaluation of surface water quality using an ecotoxicological approach: a case study of the alqueva reservoir (portugal). | freshwater reservoirs can be impacted by several hazardous substances through inputs from agricultural activity, sewage discharges, and groundwater leaching and runoff. the water quality assessment is very important for implementation of the monitoring and remediation programs to minimize the risk promoted by hazardous substances in aquatic ecosystems. evaluation of the degree of contamination of aquatic environments must not take in account only its chemical characterization but it must be comp ... | 2010 | 19396484 |
| an ancient immunity gene duplication in daphnia magna: rna expression and sequence analysis of two nitric oxide synthase genes. | no (nitric oxide) is a highly reactive free radical gas thought to play a major role in the invertebrate immune response by harming pathogens and limiting their growth. here we report on studies of nitric oxide synthase (nos) genes in the crustacean daphnia, one of the few non-insect arthropod models used to study host-pathogen interactions. while the nos gene is found as a single copy in other invertebrates, we found two copies (nos1 and nos2), which a phylogenetic reconstruction showed to be t ... | 2009 | 19416737 |
| demographic responses of daphnia magna fed transgenic bt-maize. | the food/feed quality of a variety of genetically modified (gm) maize expressing cry1ab bt-toxin was tested over the life-cycle of daphnia magna, an arthropod commonly used as model organism in ecotoxicological studies. demographic responses were compared between animals fed gm or unmodified (um) near isogenic maize, with and without the addition of predator smell. age-specific data on survival and birth rates were integrated and analysed using life tables and leslie matrices. survival, fecundit ... | 2010 | 19859805 |
| selective bactericidal potential of rice (oryza sativa l. var. japonica) hull extract on microcystis strains in comparison with green algae and zooplankton. | we examined the selective inhibitory potential of rice hull extract on the toxic cyanobacterium microcystis aeruginosa, in comparison with inhibitory effects on two green algae (ankistrodesmus convolutus and scenedesmus quadricauda) and a zooplankton (daphnia magna) species. the inhibitory effect of rice hull extract, measured by algal growth or zooplankton survival using four different concentrations of extract (1, 10, 100 and 1000 microg l(-1)), was highest on microcystis strains (average: 98% ... | 2009 | 19434356 |
| degradation of sulfamethoxazole in water by solar photo-fenton. chemical and toxicological evaluation. | in this work, the photocatalytic degradation of the antibiotic sulfamethoxazole (smx) by solar photo-fenton at pilot plant scale was evaluated in distilled water (dw) and in seawater (sw). degradation and mineralization of smx were strongly hindered in sw compared to dw. the influence of h(2)o(2) and iron concentration on the efficiency of the photocatalytic process was evaluated. an increase in iron concentration from 2.6 to 10.4 mg l(-1) showed only a slight improvement in smx degradation and ... | 2009 | 19443009 |
| evaluation of toxic and interactive toxic effects of three agrochemicals and copper using a battery of microbiotests. | three commonly used test organisms of different trophic levels (vibrio fischeri, pseudokirchneriella subcapitata and daphnia magna) were exposed to selected agrochemicals (fosthiazate, metalaxyl-m, imidacloprid) and copper, in single doses or in binary mixtures. the toxicity of each single compound varied up to two orders of magnitude, depending on the test species examined. v. fischeri was the most sensitive test organism regarding fosthiazate and metalaxyl-m, indicating an ic(50) value of 0.20 ... | 2009 | 19447473 |
| uptake and toxicity of hexafluoroarsenate in aquatic organisms. | the arsenic species hexafluoroarsenate has been described as a contaminant of surface waters of anthropogenic origin. here, we undertake to identify the most sensitive biological receptor among several sentinel aquatic species used in eco-toxicological assessment and to understand toxicity in terms of internal dose. therefore, a screening of short-term effects using different aquatic organisms (bacterium vibrio fischeri, fish danio rerio, crustacean daphnia magna and green alga desmodesmus subsp ... | 2010 | 19900693 |
| measuring parasite fitness under genetic and thermal variation. | accurate measures of parasite fitness are essential to study host-parasite evolution. parasite fitness depends on several traits involved in establishing infection, growth and transmission. individually, these traits provide a reasonable approximation of fitness, but they may also be under the shared control of both host and parasite genetics (g(h) x g(p) interactions), or be differentially sensitive to environmental variation. using the natural host-parasite system daphnia magna-pasteuria ramos ... | 2009 | 19455181 |
| differences in phytotoxicity and dissipation between ionized and nonionized oil sands naphthenic acids in wetland plants. | naphthenic acids (nas) are composed of alkyl-substituted acyclic and cycloaliphatic carboxylic acids and, because they are acutely toxic to fish, are of toxicological concern. during the caustic hot-water extraction of oil from the bitumen in oil sands deposits, nas become concentrated in the resulting tailings pond water. the present study investigated if dissipation of nas occurs in the presence of hydroponically grown emergent macrophytes (typha latifolia, phragmites australis, and scirpus ac ... | 2009 | 19469588 |
| genotoxic effects of nonylphenol and bisphenol a exposure in aquatic biomonitoring species: freshwater crustacean, daphnia magna, and aquatic midge, chironomus riparius. | the geno-, and eco-toxicity of nonlyphenol (np) and bisphenol a (bpa) were investigated in daphnia magna, and chironomus riparius. bpa may exert a genotoxicity on both species, whereas np-induced dna damage occurred only in c. riparius. in np-exposed d. magna, increased mortality, without effect on dna integrity was observed, an example of a false-negative result from the biomarkers perspective. false-positive results from the genotoxicity were observed in bpa-exposed d. magna and in np-exposed ... | 2009 | 19475328 |
| influence of environmental factors on the response of a natural population of daphnia magna (crustacea: cladocera) to spinosad and bacillus thuringiensis israelensis in mediterranean coastal wetlands. | the present study was undertaken to assess the impact of a candidate mosquito larvicide, spinosad (8, 17 and 33 microg l(-1)) on a field population of daphnia magna under natural variations of water temperature and salinity, using bti (0.16 and 0.50 microl l(-1)) as the reference larvicide. microcosms (125 l) were placed in a shallow temporary marsh where d. magna was naturally present. the peak of salinity observed during the 21-day observation period may have been partly responsible for the de ... | 2010 | 19939529 |
| co-combustion of coal and sewage sludge: chemical and ecotoxicological properties of ashes. | the co-combustion of sewage sludge (ss) and coal is widely used for the treatment and thermal valorization of ss produced in wastewater treatment plants. the chemical and ecotoxicological properties of the ashes produced in this thermal treatment have not been fully studied. two combustion tests were performed in a fluidized bed combustor. colombian coal was used as fuel in test a. a blend (1+1) of this coal and a stabilized ss (biogran) was used in a second test b. samples of the bottom and fly ... | 2009 | 19515486 |
| identification of water soluble and particle bound compounds causing sublethal toxic effects. a field study on sediments affected by a chlor-alkali industry. | a combination of cost effective sublethal daphnia magna feeding tests, yeast- and cell culture-based bioassays and toxicity identification evaluation (tie) procedures was used to characterize toxic compounds within sediments collected in a river area under the influence of the effluents from a chlor-alkali industry (ebro river, ne spain). tests were designed to measure and identify toxic compounds in the particulate and filtered water fractions of sediment elutriates. the combined use of bioassa ... | 2009 | 19540603 |
| priority effects in experimental populations of the cyanobacterium microcystis. | the arrival order of colonists in developing populations can have a lasting influence on community and population structure, a phenomenon referred to as priority effects. to explore whether such priority effects are important in determining strain composition of populations of the cyanobacterium microcystis, four microcystis strains, isolated from a single lake and differing in functional traits, were grown during 4 weeks in the laboratory in all possible pairwise combinations, with the two stra ... | 2009 | 19555379 |
| a comparison of nanoparticle and fine particle uptake by daphnia magna. | the use of nanoparticles in various applications is steadily on the rise, with use in a range of applications, including printer toner, sunscreen, medical imaging, and enhanced drug delivery. while research on human effects via, for example, inhalation is relatively well developed, the environmental assessment of nanoparticles is in its infancy. in the present study, we assessed the uptake and quantitative accumulation, as well as the depuration, of a model nanoparticle, a 20-nm fluorescent carb ... | 2009 | 19588999 |
| removal of organics from different types of landfill leachate by ozonation. | the objective of this investigation was determination of feasibility of ozonation for treatment of leachates from municipal landfill. efficiency of ozonation was determined for two leachates, different in age, composition and toxicity. we have studied the impact of ozonation time on removal of organics. the efficiency of treatment was monitored by cod, bod(5) and doc analyses, removal of nitrogen compounds, as well as changes in toxicity. therefore, acute toxicity tests with luminiscent bacteria ... | 2009 | 19657154 |
| development of an inhibitive enzyme assay for copper. | in this work the development of an inhibitive assay for copper using the molybdenum-reducing enzyme assay is presented. the enzyme is assayed using 12-molybdophosphoric acid at ph 5.0 as an electron acceptor substrate and nadh as the electron donor substrate. the enzyme converts the yellowish solution into a deep blue solution. the assay is based on the ability of copper to inhibit the molybdenum-reducing enzyme from the molybdate-reducing serratia sp. strain dry5. other heavy metals tested did ... | 2009 | 20112861 |
| whole effluent assessment of industrial wastewater for determination of bat compliance. part 2: metal surface treatment industry. | toxicity testing has become a suitable tool for wastewater evaluation included in several reference documents on best available techniques of the integrated pollution prevention and control (ippc) directive. the ippc directive requires that for direct dischargers as well as for indirect dischargers, the same best available techniques should be applied. within the study, the whole effluent assessment approach of ospar has been applied for determining persistent toxicity of indirectly discharged w ... | 2010 | 20127188 |
| pilot study on control of phytoplankton by zooplankton coupling with filter-feeding fish in surface water. | a pilot-scale facility was originally designed to control phytoplankton in algae-laden reservoir water characterized by summer cyanobacteria blooms (mainly microcystis flos-aquae). the system made good use of the different food habits of daphnia magna and silver carp. zooplankton (daphnia magna), filter-feeding fish (silver carp), and zooplankton (daphnia magna) were stocked in three separated tanks in sequence, respectively. thus, single-cell phytoplankton and some microcystis flos-aquae in sma ... | 2009 | 19657169 |
| acute toxicity of metals and reference toxicants to a freshwater ostracod, cypris subglobosa sowerby, 1840 and correlation to ec(50) values of other test models. | the ostracod cypris subglobosa sowerby, 1840 static bioassay test on the basis of a 48h of 50% of immobilization (ec(50)) has been used to measure the toxicity of 36 metals and metalloids and 12 reference toxicants. among the 36 metals and metalloids, osmium (os) was found to be the most toxic in the test while boron (b), the least toxic. the ec(50) values of this study revealed positive linear relationship with the established test models of cladoceran (daphnia magna), sludge worm (tubifex tubi ... | 2009 | 19683870 |
| expression of bacillus cereus hemolysin ii in bacillus subtilis renders the bacteria pathogenic for the crustacean daphnia magna. | hemolysin ii (hlyii) is a pore-forming toxin of the opportunistic pathogen bacillus cereus. despite our understanding of the mechanism of hlyii cytotoxicity in vitro, many of its characteristics, including potential target cells, conditions of its action and expression, are not known. here we report that the expression of hlyii in bacillus subtilis renders the bacteria hemolytic and is able to kill the crustacean daphnia magna. the hemolytic activity of hlyii-encoded b. subtilis strains in cultu ... | 2009 | 19686345 |
| identification of intermediates and assessment of ecotoxicity in the oxidation products generated during the ozonation of clofibric acid. | the degradation of an aqueous solution of clofibric acid was investigated during catalytic and non-catalytic ozonation. the catalyst, tio(2), enhanced the production of hydroxyl radicals from ozone and raised the fraction or clofibric acid degraded by hydroxyl radicals. the rate constant for the reaction of clofibric acid and hydroxyl radicals was not affected by the presence of the catalyst. the toxicity of the oxidation products obtained during the reaction was assessed by means of vibrio fisc ... | 2009 | 19709806 |
| life history responses of daphnia magna feeding on toxic microcystis aeruginosa alone and mixed with a mixotrophic poterioochromonas species. | the toxic effects of a mixotrophic golden alga (poterioochromonas sp. strain zx1) and a cyanobacterium microcystis aeruginosa grazed by poterioochromonas to a cladoceran were investigated through life history experiments using daphnia magna. poterioochromonas cultured in two ways (fed m. aeruginosa in an inorganic medium or grown in an organic medium) both induced starvation-like effects on d. magna, indicating that poterioochromonas is neither acutely toxic nor a good food for d. magna. despite ... | 2009 | 19748652 |
| toxicity assays applied to wastewater treatment. | the utility and validity of toxicity tests for monitoring of wastewater treatment have been assessed. the evaluated acute toxicity tests have been vibrio fischeri, selenastrum capricornotum and daphnia magna tests. the validation studies indicated that the acute toxicity tests can be considered as high sensitivity analytical tools to detect common environmental concentrations of the pollutants at concentration levels as low as ngl(-1). the toxicity tests showed to have discriminatory ability to ... | 2005 | 18969807 |
| effects of temperature and dietary sterol availability on growth and cholesterol allocation of the aquatic keystone species daphnia. | enhanced water temperatures promote the occurrence of cyanobacterial blooms, which may be detrimental to aquatic herbivores. especially, the often-dominant crustaceans could be negatively affected because cyanobacteria are deficient in phytosterols, which are required by the crustaceans to form the membrane component cholesterol, which in turn plays a role in thermal adaptation. here, we determined the influence of temperature on growth, reproduction and the allocation of dietary sterol into som ... | 2009 | 19749097 |
| colimitation of a freshwater herbivore by sterols and polyunsaturated fatty acids. | empirical data providing evidence for a colimitation of an herbivore by two or more essential nutrients are scarce, particularly in regard to biochemical resources. here, a graphical model is presented, which describes the growth of an herbivore in a system with two potentially limiting resources. to verify this model, life-history experiments were conducted with the herbivore daphnia magna feeding on the picocyanobacterium synechococcus elongatus, which was supplemented with increasing amounts ... | 2009 | 19324803 |
| ecotoxicity assessment of lipid regulators in water and biologically treated wastewater using three aquatic organisms. | the high consumption of blood lipid regulators is leading to frequent reports of the occurrence of fibrates in natural streams and wastewater effluents. this paper describes a study undertaken to evaluate the acute toxicity of bezafibrate, clofibric acid, gemfibrozil, and fenofibric acid, a metabolite of fenofibrate whose ecotoxicity has not been previously reported. | 2010 | 19333638 |
| molecular cloning of daphnia magna catalase and its biomarker potential against oxidative stresses. | catalase (ec 1.11.1.6) is an important antioxidant enzyme that protects aerobic organisms against oxidative damage by degrading hydrogen peroxide to oxygen and water. catalase mrnas have been cloned from many species and employed as useful biomarkers of oxidative stress. in the present study, we cloned the cdna from the catalase gene in daphnia magna, analyzed its catalytic properties, and investigated mrna expression patterns after the exposure to known oxidative stressors. the catalase proxima ... | 2010 | 20470898 |
| effectiveness of ozonation and chlorination on municipal wastewater treatment evaluated by a battery of bioassays and biomarkers. | a battery of bioassays, including biological toxicity as well as in vitro mouse spleen lymphoproliferative responses and cytokine production, was conducted to compare the effectiveness of tertiary treatment methods such as coagulation (coag) and absorption on granular activated carbon (gac) and disinfection processes such as chlorination and ozonation in removing toxic or stress inducing agents from reclaimed wastewater. whole effluent toxicity (wet) testing of secondary treated (st) wastewater ... | 2009 | 19759452 |
| genetic variation in the cellular response of daphnia magna (crustacea: cladocera) to its bacterial parasite. | linking measures of immune function with infection, and ultimately, host and parasite fitness is a major goal in the field of ecological immunology. in this study, we tested for the presence and timing of a cellular immune response in the crustacean daphnia magna following exposure to its sterilizing endoparasite pasteuria ramosa. we found that d. magna possesses two cell types circulating in the haemolymph: a spherical one, which we call a granulocyte and an irregular-shaped amoeboid cell first ... | 2010 | 20534618 |
| assessment of peracetic acid disinfected effluents by microbiotests. | bioassays were performed by commercially available kits on peracetic acid (paa) solutions, at different concentrations, and on secondary effluents (from two different wastewater treatment plants) after disinfection at bench-scale, considering both samples containing residual active paa and the same samples where residual paa was quenched. four indicator organisms were used: vibrio fischeri, thamnocephalus platyurus, daphnia magna, and selenastrum capricornutum. the experiments lead to conclude t ... | 2009 | 19764220 |
| a comparison of the chronic effects of human pharmaceuticals on two cladocerans, daphnia magna and ceriodaphnia dubia. | scientific researchers and regulators are focusing attention on trace quantities of pharmaceuticals in wastewater effluents and surface waters, resulting in an increased level of concern regarding the potential environmental impact of these compounds. the current european regulatory guideline requires evaluation of the chronic effects of active pharmaceutical ingredients on daphniamagna. based on the life cycle of d. magna, chronic studies to establish survival and reproductive endpoints require ... | 2010 | 20547406 |
| bacteria dispersal by hitchhiking on zooplankton. | microorganisms and zooplankton are both important components of aquatic food webs. although both inhabit the same environment, they are often regarded as separate functional units that are indirectly connected through nutrient cycling and trophic cascade. however, research on pathogenic and nonpathogenic bacteria has shown that direct association with zooplankton has significant influences on the bacteria's physiology and ecology. we used stratified migration columns to study vertical dispersal ... | 2010 | 20547852 |
| exploring the molecular landscape of host-parasite coevolution. | host-parasite coevolution is a dynamic process that can be studied at the phenotypic, genetic, and molecular levels. although much of what we currently know about coevolution has been learned through phenotypic measures, recent advances in molecular techniques have provided tools to greatly deepen this research. both the availability of full-genome sequences and the increasing feasibility of high-throughput gene expression profiling are leading to the discovery of genes that have a key role in a ... | 2009 | 19843595 |
| ecotoxicity and genotoxicity assessment of cytotoxic antineoplastic drugs and their metabolites. | in spite of growing scientific concern about pharmaceuticals in the environment, there is still a lack of information especially with regard to their metabolites. the present study investigated ecotoxicity and genotoxicity of three widely used cytostatic agents 5-fluorouracil (5-fu), cytarabine (cyt) and gemcitabine (gemc) and their major human metabolites, i.e. alpha-fluoro-beta-alanine (fbal), uracil-1-beta-d-arabinofuranoside (arau) and 2',2'-difluorodeoxyuridine (dfdu), respectively. effects ... | 2010 | 20624627 |
| aquatic multi-species acute toxicity of (chlorinated) anilines: experimental versus predicted data. | aquatic toxicity information is essential in environmental risk assessment to determine the potential hazards and risks of new and existing chemicals. prediction and modelling techniques, such as quantitative structure activity relationships (qsar) and species sensitivity distributions (ssds), are applied to fill data gaps and to predict, assess and extrapolate the toxicity of chemicals. in this study, both techniques (i.e. the ecosar programme as qsar tool and ssds) were assessed for a set of p ... | 2010 | 20637490 |
| a saccharomyces cerevisiae-based bioassay for assessing pesticide toxicity. | this study evaluates the toxic effect of three pesticides (azoxystrobin, cymoxanil, and diuron) on the yeast saccharomyces cerevisiae for the development of a new bioassay based on inhibition of s. cerevisiae metabolic activity at the level of adenosine-5-triphosphate (atp) synthesis, as compared with two different toxicity tests based on inhibition of daphnia magna mobility (nf en iso 6341) and inhibition of vibrio fisheri activity (nf en iso 11348). the s. cerevisiae bioassay is cheaper and 96 ... | 2009 | 19856193 |
| photodegradation of sulfamethoxazole in various aqueous media: persistence, toxicity and photoproducts assessment. | the photochemical transformation of sulfamethoxazole (smx) was investigated in different water matrices: distilled water (dw), distilled water+nitrate (10 and 20 mg l(-1)) and seawater (sw) to evaluate its persistence, toxicity and degradation pathway. a solar simulator suntest cps+ was used for the irradiation experiments. identification of transformation products was performed in dw by liquid chromatography-time of flight-mass spectrometry (lc-tof-ms). acute toxicity of irradiated solutions wa ... | 2009 | 19879626 |
| environmental risk assessment of human pharmaceuticals in the european union: a case study with the β-blocker atenolol. | β-adrenergic receptor blockers (β-blockers) are applied to treat high blood pressure, ischemic heart disease, and heart rhythm disturbances. due to their widespread use and limited human metabolism, β-blockers are widely detected in sewage effluents and surface waters. β-adrenergic receptors have been characterized in fish and other aquatic animals, so it can be expected that physiological processes regulated by these receptors in wild animals may be affected by the presence of β-blockers. becau ... | 2010 | 19886730 |
| enantioselective interaction with acetylcholinesterase of an organophosphate insecticide fenamiphos. | enantioselectivity in the environmental behavior and ecotoxicity of chiral pesticide is widely observed. however, the investigation of the enantioselective mechanisms remains limited. in this study, we used fenamiphos (fap), an organophosphorus insecticide, to study enantioselectivity in toxicity to arthropods and the inhibition potential towards acetylcholinesterase (ache) in the rat pheochromocytoma 12 (pc 12) cell line. furthermore, we carried out molecular docking to help explain the mechani ... | 2010 | 19899158 |
| pathogen dose infectivity curves as a method to analyze the distribution of host susceptibility: a quantitative assessment of maternal effects after food stress and pathogen exposure. | stress conditions have been found to change the susceptibility of hosts or their offspring to infection. the usual method of testing at just one parasite dose level does not allow conclusions on the distribution of susceptibility. to better understand the epidemiology and evolution of host-parasite systems, however, knowledge about the distribution of host susceptibility, the parameters that characterize it, and how it changes in response to environmental conditions is required. we investigated ... | 2010 | 19911987 |
| target gene approaches: gene expression in daphnia magna exposed to predator-borne kairomones or to microcystin-producing and microcystin-free microcystis aeruginosa. | two major biological stressors of freshwater zooplankton of the genus daphnia are predation and fluctuations in food quality. here we use kairomones released from a planktivorous fish (leucaspius delineatus) and from an invertebrate predator (larvae of chaoborus flavicans) to simulate predation pressure; a microcystin-producing culture of the cyanobacterium microcystis aeruginosa and a microcystin-deficient mutant are used to investigate effects of low food quality. real-time quantitative polyme ... | 2009 | 19917101 |
| phytoplankton, not allochthonous carbon, sustains herbivorous zooplankton production. | terrestrial organic matter inputs have long been thought to play an important role in aquatic food web dynamics. results from recent whole lake (13)c addition experiments suggest terrestrial particulate organic carbon (t-poc) inputs account for a disproportionate portion of zooplankton production. for example, several studies concluded that although t-poc only represented approximately 20% of the flux of particulate carbon available to herbivorous zooplankton, this food source accounted for appr ... | 2009 | 19934044 |
| draft genome sequence of the daphnia pathogen octosporea bayeri: insights into the gene content of a large microsporidian genome and a model for host-parasite interactions. | the highly compacted 2.9-mb genome of encephalitozoon cuniculi placed the microsporidia in the spotlight, encoding a mere 2,000 proteins and a highly reduced suite of biochemical pathways. this extreme level of reduction is not universal across the microsporidia, with genomes known to vary up to sixfold in size, suggesting that some genomes may harbor a gene content that is not as reduced as that of enc. cuniculi. in this study, we present an in-depth survey of the large genome of octosporea bay ... | 2009 | 19807911 |
| transgenerational effects of poor elemental food quality on daphnia magna. | environmental effects on parents can strongly affect the phenotype of their offspring, which alters the heritability of traits and the offspring's responses to the environment. we examined whether p limitation of the aquatic invertebrate, daphnia magna, alters the responses of its offspring to inadequate p nutrition. mother daphnia consuming p-poor algal food produced smaller neonates having lower body p content compared to control (p-rich) mothers. these offspring from p-stressed mothers, when ... | 2010 | 19957090 |
| assessing the toxicity on [c3mim][tf2n] to aquatic organisms of different trophic levels. | ionic liquids (ils) are an exciting class of neoteric solvents that are being object of great attention as a potential replacement to conventional environmental damaging solvents in industrial applications. despite some progress concerning ils' toxicity and their environmental impact, the information about these compounds is still scarce. in this work, biological tests were performed to establish the toxicity of 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, [c3mim][tf2n], in fi ... | 2010 | 20018392 |
| effects of ivermectin-spiked cattle dung on a water-sediment system with the aquatic invertebrates daphnia magna and chironomus riparius. | a two-species test using a water-sediment test system was performed to investigate chronic effects of the parasiticide ivermectin on daphnia magna and chironomus riparius. to simulate exposure by direct excretion of cattle into surface waters, ivermectin was applied via spiked cattle dung. the parasiticide was applied once, at concentrations ranging from 11 to 1314 microg kg(-1) dung dry weight. the highest concentration corresponds to the maximum concentration in dung 3 days after topical appli ... | 2010 | 20060604 |
| use of a (quantitative) structure-activity relationship [(q)sar] model to predict the toxicity of naphthenic acids. | naphthenic acids (na) are a complex mixture of carboxylic acids that are natural constituents of oil sand found in north-eastern alberta, canada. na are released and concentrated in the alkaline water used in the extraction of bitumen from oil sand sediment. na have been identified as the principal toxic components of oil sands process-affected water (ospw), and microbial degradation of lower molecular weight (mw) na decreases the toxicity of na mixtures in ospw. analysis by proton nuclear magne ... | 2010 | 20077300 |
| does the actual standard of 0.1 microg/l overestimate or underestimate the risk of plant protection products to groundwater ecosystems? | the present groundwater standard of 0.1 microg/l for plant protection products (ppps) has been under much debate because an ecotoxicological base is missing. in the present study, groundwater threshold values were calculated for all ppps currently included in annex i to directive 91/414/eec using three different approaches: (1) first-tier (daphnia magna and vibrio fisheri); (2) species sensitivity distributions, constructed for surrogate freshwater organisms for the truncated groundwater biodive ... | 2010 | 20083305 |
| chronic toxicity and cytotoxicity of synthetic pyrethroid insecticide cis-bifenthrin. | with the increasing use of synthetic pyrethroids (sps), the significance of ecological safety and health risk is an emerging concern. in this study, we evaluated the chronic aquatic toxicity of cis-bifenthrin (cis-bf) in daphnia magna and its cytotoxicity in chinese hamster ovary (cho) cells as well as human cervical carcinoma (hela) cells. chronic aquatic toxicity tests showed that cis-bf could significantly affect the reproduction of d. magna. the lowest observed effective concentration and th ... | 2009 | 20131602 |
| quantification of water solubilized cdse/zns quantum dots in daphnia magna. | the relative transparency of daphnia magna (daphnia) and the unique optical properties of quantum dots (qds) were paired to study the accumulation potential and surface coating effects on uptake of amphiphilic polymer coated cdse/zns qds. fluorescence confocal laser scanning microscopy was used to visualize and spectrally distinguish qds from competing autofluorescent signals arising from the daphnia themselves and their food sources. qds were found to accumulate within the digestive tracts of d ... | 2010 | 20131897 |
| chronic effects of cyanobacterial toxins on daphnia magna and their offspring. | the zooplankton grazer daphnia magna endures living in water bodies up to moderate densities of cyanobacteria, such as microcystis spp., known for producing toxic secondary metabolites. although daphnids are affected via decreased food filtering, inhibition of digestive proteases and lethality, development of tolerance against cyanobacterial toxins has also been observed. aim of our study was to investigate in detail chronic effects of cyanobacterial toxins, with emphasis on microcystin, on d. m ... | 2010 | 20132836 |
| oxidative stress responses of daphnia magna exposed to tio(2) nanoparticles according to size fraction. | size is one of important factors determining titanium dioxide nanoparticle (tio(2) np) toxicity since penetration is eased with decreasing particle size and bioavailability is increased. the effect of particle size on oxidative stress against titanium dioxide nanoparticle (tio(2) np) exposure to daphnia magna was investigated with both acute and chronic toxicity tests. experiments on biochemical responses, repeatedly performed after size fractionation of the nps using filtration, focused on the ... | 2010 | 20153877 |
| comparison of laser ablation-inductively coupled plasma-mass spectrometry and micro-x-ray fluorescence spectrometry for elemental imaging in daphnia magna. | visualization of elemental distributions in thin sections of biological tissue is gaining importance in many disciplines of biological and medical research. laser ablation-inductively coupled plasma-mass spectrometry (la-icp-ms) and scanning micro-x-ray fluorescence spectrometry (micro-xrf) are two widely used microanalytical techniques for elemental mapping. this article compares the capabilities of the two techniques for imaging the distribution of selected elements in the model organism daphn ... | 2010 | 20226927 |
| an assessment of chemical and physical parameters, several contaminants including metals, and toxicity in the seven major wastewater treatment plants in the state of aguascalientes, mexico. | forty-eight hours acute toxicity tests were employed with daphnia magna and lecane quadridentata to assess the influents and effluents of the seven most important wastewater treatment plants (wtp) in the state of aguascalientes, mexico, during the 2006 dry and rainy seasons. the wtp of the city of aguascalientes treated 1948 ls(-1). the remaining six plants treated wastewater in the range from 28 to 93 ls(-1). plants efficiently removed toxicity when daphnia magna was used as a model organism, b ... | 2010 | 20390835 |
| determination of ec50 toxicity data of selected heavy metals toward heterocypris incongruens and their comparison to "direct-contact" and microbiotests. | the sensitivity of heterocypris incongruens to selected heavy metal ions is discussed. although the ostracodtoxkit ® has been present on the market for a few years, data on its selectivity and sensitivity to toxicants is scarce; such data is indispensable when interpreting the results of sediment toxicity. the lc(50) and ec(50) results with the ostracodtoxkit ® are compared with those obtained with other commercially available "direct-contact" tests (utilizing hyalella azteca and chironomus ripa ... | 2011 | 20431939 |