| acute toxicity of dechlorinated ddt, chlordane and lindane to bluegill (lepomis macrochirus) and daphnia magna. | | 1979 | 88975 |
| [resistance of yeast cells to plastics and elastics]. | for the investigation of plastics and elastics several sensitive biological methods are in use. in the pharmacopeia of gdr, 2nd edition, a safety-test on isolated frogheart is prescribed for plastics and a safety-test on daphnia magna for elastics. ionescu-stoian had recommended a test using saccharomyces cerevisiae. we found a good conformity of the result given by this test with the results of the daphnia-test. on the other hand, the saccharomyces cerevisiae-test is much more sensitive than th ... | 1978 | 356015 |
| toxicity of microencapsulated permethrin to selected nontarget aquatic invertebrates. | microencapsulated permethrin (penncapthrin) was evaluated under laboratory conditions for its toxicity toward several nontarget aquatic invertebrates. average lc50 estimates for selected lotic invertebrates, based on a one hour dosing regime, were: 2.71 mg/l for simulium vittatum, 4.59 mg/l for hydropsyche spp., and 13.41 mg/l for isonychia bicolor. in acute static tests with daphnia magna, there was no significant difference (p less than or equal to 0.05) between the toxicity of penncapthrin at ... | 1991 | 2014998 |
| [daphnia magna straus as consumers of enteropathogenic bacteria]. | the ability of daphnia magna straus to digest enteropathogenic bacteria, i.e. salmonella, shigella and yersinia was studied in a series of experiments. high antibacterial activity of daphnia magna straus against these enteropathogenic bacteria was demonstrated by bacteriological and radionuclide methods. thus, on the 3d-5th day of experiment a complete water clearance was observed in experimental flasks where daphnia were fed salmonella, shigella and yersinia, while attempts to isolate bacteria ... | 1984 | 6498328 |
| ecotox-evaluation strategy for soil bioremediation exemplified for a pah-contaminated site. | during a bioremediation of a pah-contaminated site chemical and biological analyses were carried out. the biological investigations included ecotoxicological analyses in the aqueous extract, (pseudomonas putida, photobacterium phosphoreum, daphnids, algae, fish) and analyses in the soil with introduced organisms (plants, earthworms) and natural soil organisms (nematodes, microorganisms). in all test systems a correspondence between decreasing toxicity and degradation of the easily biodegradable ... | 1994 | 7922149 |
| the use of daphnia magna for detection of okadaic acid in mussel extracts. | okadaic acid (oa), the main toxin responsible for diarrheic shellfish poisoning (dsp) has toxicity for daphnia magna (ec50 = 15 +/- 1.8 micrograms/l). a daphnia bioassay was developed and used to analyse okadaic acid in mussel extracts. a linear correlation was found between oa concentration determined by the daphnia bioassay and by hplc assay (r = 0.85; p < 0.001). the daphnia bioassay can measure oa levels 10 times below the threshold of the mouse bioassay method. it is an inexpensive sensitiv ... | 1993 | 8224329 |
| dna cleavage, antiviral and cytotoxic reactions photosensitized by simple enediyne compounds. | very potent antibiotic antitumor natural products contain a enediyne moiety which, upon thermal activation, is capable of abstracting hydrogens from dna. 1,6-diphenyl-3-hexene-1,5-diyne was selected as a candidate for inducing dna strand breaks photochemically. easily interconverted with light, both geometric isomers 1 and 2 were expected to be phototoxic. as anticipated, they photosensitized the production of strand breaks in double-stranded supercoiled pbr322, and in single-stranded m13 dna. t ... | 1993 | 8301409 |
| environmental effects of the usage of avermectins in livestock. | abamectin (avermectin b1) and ivermectin (22,23-dihydroavermectin b1) are high molecular weight hydrophobic compounds, active against a variety of animal parasites and insects. numerous environmental fate and effects studies have been carried out in the development of these two compounds as antiparasitic agents and for abamectin as a crop protection chemical. they were found to be immobile in soil (koc > or = 4000), rapidly photodegraded in water (degradation half-life (t1/2) in the summer 0.5 d ... | 1993 | 8346626 |
| phototoxicity of (1h-indenyl)thiophenes. | the (1h-indenyl)thiophene derivatives 2 and 3 were recently reported to be excellent singlet oxygen sensitizers, comparable to alpha-terthienyl (1). the phototoxicity of these compounds was compared, using human erythrocytes, aedes aegypti mosquito larvae, daphnia magna, and fish (fathead minnows, pimephales promelas). the known ranking of the photooxidation properties was found to be a good predictor of phototoxic properties in erythrocytes and mosquito larvae but not in daphnias. all three com ... | 1993 | 8378432 |
| predation by a cyprinodontid fish, aphanius mento, on culex pipiens: effects of alternative prey and vegetation. | we assessed the effects of an alternative prey species (daphnia magna) and a submergent plant (ceratophyllum demersum) on the efficiency of the fish, aphanius mento, to prey on mosquito (culex pipiens) larvae in the laboratory. aphanius mento is an untested biological control candidate of mosquitoes. when d. magna was introduced with equal numbers of cx. pipiens larvae, there was a 50.7% reduction in predation by a. mento on the mosquito larvae. however, the more d. magna a fish ate, the more cx ... | 1993 | 8245949 |
| inactivation of glutaraldehyde by reaction with sodium bisulfite. | the microbiocidal activity of glutaraldehyde was inactivated by reaction with sodium bisulfite via formation of a proposed glutaraldehyde-bisulfite complex. high-performance liquid chromatography (hplc) analysis of 2% (0.2m) alkaline glutaraldehyde indicated complete loss of glutaraldehyde at a 2.2:1 molar ratio of sodium bisulfite to glutaraldehyde. neither 1.7% (0.17 m) sodium bisulfite alone nor the glutaraldehyde-bisulfite complex was microbiocidal when tested against escherichia coli, pseud ... | 1996 | 8604152 |
| toxicity of fluoranthene to daphnia magna, hyalella azteca, chironomus tentans, and stylaria lacustris in water-only and whole sediment exposures. | | 1996 | 8661471 |
| human acute toxicity prediction of the first 50 meic chemicals by a battery of ecotoxicological tests and physicochemical properties. | five acute bioassays consisting of three cyst-based tests (with artemia salina, streptocephalus proboscideus and brachionus calyciflorus), the daphnia magna test and the bacterial luminescence inhibition test (photobacterium phosphoreum) are used to determine the acute toxicity of the 50 priority chemicals of the multicentre evaluation of in vitro cytotoxicity (meic) programme. these tests and five physiocochemical properties (n-octanol-water partition coefficient, molecular weight, melting poin ... | 1994 | 8132177 |
| toxicity identification evaluations for the investigation of fish kills: a case study. | a large fish-kill was observed in the river tajo during the spring-summer of 1991. the mortality was first detected between aranjuez and toledo, affecting several fish species. then it was slowly going downstream, affecting only carp (cyprinus carpio), reaching the spanish-portuguese border several months later. short-term toxicity tests on daphnia magna and in vitro cytotoxicity tests on rtg-2 cells were used as toxicity monitoring systems in water samples and different water fractions. the fis ... | 1994 | 8044634 |
| characterization of lake ladoga sediments. i. toxicity to chironomus riparius and daphnia magna. | toxicity of surficial sediment of lake ladoga, russia, was studied using bioassays with a midge, chironomus riparius and daphnia magna. many lake ladoga sediments caused high mortality of midge larvae in 10-d growth and 40-d emergence tests. in most sediments the biomass production of chironomids was also lowered. however, no statistically significant effect on timing of emergence was observed. sediment elutriate or pore water tests did not exhibit toxicity to daphnia magna. the adverse effects ... | 1996 | 8920594 |
| [hygienic express-diagnosis of the toxicity of drinking water disinfectants using biotests]. | toxicity of water treated by two disinfectants, aokh-k and gaseous chlorine, was studied by biotesting on daphnia magna, tetrahymena pyriformis (tp) and renal epithelium of porcine embryo (repe). the study showed that aokh-k preparation is nontoxic and chlorine toxic for tp and repe in concentrations 2 and 3 mg/l. | 1994 | 7721136 |
| lethal and sublethal effects of azulene and longifolene to microtox(r), ceriodaphnia dubia, daphnia magna, and pimephales promelas. | | 1997 | 8975804 |
| toxicity of sediments and sediment pore waters from the grand calumet river-indiana harbor, indiana area of concern. | the assessment of contaminated sediments is a difficult task due to the complex nature of the sediment matrix and the potential for exposure of aquatic organisms to in-place contaminants via several routes. differential species sensitivity also precludes the completion of a meaningful environmental assessment with only one species. therefore, a battery of assays approach with the microtox assay, 48 hr daphnia magna and ceriodaphnia dubia tests and a 10-day chironomous tentans test was used to ev ... | 1993 | 7691537 |
| the toxicity of the mutagen 'mx' and its analogue, mucochloric acid, to rainbow trout hepatocytes and gill epithelial cells and to daphnia magna. | the cytotoxicity of the, in salmonella, potent mutagenic compound, 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5h)-furanone (mx) and its structural analogue 3,4-dichloro-5-hydroxy-2[5h]-furanone (mucochloric acid, mca), was studied in freshly isolated rainbow trout hepatocytes and gill epithelial cells by determining 86rb-leakage and decrease in fluorescence intensity in calcein am-loaded cells. the acute toxicity of the compounds to daphnia magna was studied by determining the concentration causing ... | 1995 | 7624884 |
| the environmental risks of industrial waste disposal: an experimental approach including acute and chronic toxicity studies. | the toxicity of 15 leachates of various solid industrial wastes accepted in an engineered landfill has been studied. a cost-effective battery of tests allowing evaluation of acute and chronic toxicity, as well as genotoxicity, and investigations on different trophic levels in the aquatic environment has been used. acute toxicity was tested on bacteria (microtox assay with photobacterium phosphoreum) and microcrustaceans (daphnia magna immobilization assay). a growth inhibition test of microalgae ... | 1994 | 7525226 |
| phototoxicology. 3. comparative toxicity of trinitrotoluene and aminodinitrotoluenes to daphnia magna, dugesia dorotocephala, and sheep erythrocytes. | 2,4,6-trinitrotoluene (tnt) and compounds associated with its production are toxic and phototoxic to a wide range of biota. the planarian dugesia dorotocephala, but not daphnia magna, metabolized tnt (1 mg/liter) to 4-amino-2,6-dinitrotoluene (4a; 0.4 mg/liter) and 2-amino-4,6-dinitrotoluene (2a; 0.2 mg/liter). coexposure to near-ultraviolet (nuv) light enhanced the toxicity of 2a more than that of tnt and 4a. the toxicities of tnt, 4a, and 2a to du. dorotocephala were all decreased by glutathio ... | 1994 | 7525203 |
| remarks about some pharmacopoieal safety tests for plastics and elastomers. | a survey of the biological methods for quality control of plastics and elastomers included in pharmacopoeias is given. the value of some of these methods (test for pyrogen-like substances, test for acute systemic toxicity in mice, tests on frog hearts, on daphnia magna and on rat sperm, mode of extraction) is discussed. | 1980 | 7454616 |
| comparative studies on ecotoxicology of synthetic detergents. | to predict the comparative toxicological response of synthetic detergents on aquatic ecosystems, the effects of various concentrations of neutralized alkyl benzene sulfonate were studied. the median tolerance limit at 48 hr, 95% confidence limit, slope function, presumable harmless concentration, and rate of survival of different species of aquatic fauna such as water fleas (daphnia magna), mosquito larvae (culex pipiens), slug worms (tubifex rivulorum), snails (lymnaea vulgaris), tadpoles (rana ... | 1983 | 6662055 |
| role of particulate organic matter in decreasing accumulation of polynuclear aromatic hydrocarbons by daphnia magna. | | 1983 | 6357107 |
| toxicity of aquatic herbicides to daphnia magna. | accurate determination of the acute toxicities of a series of 16 aquatic herbicides to daphnia magna reveals that several of them may present a hazard to food-chain microfauna whether the compounds are environmentally destroyed or not. | 1966 | 5914766 |
| correlation of metal ion toxicities to mice. | recently reported correlations of acute ip ld50 metal ion toxicities to mice by turner et al. (1983), have been re-investigated using the ion-specific parameters reported by kaiser (1980) for sublethal metal ion toxicities to daphnia magna. for the 15 ions with partially or completely filled d-shells, rh(iii), fe(iii), cr(iii), mn(ii), co(ii), pd(ii), ni(ii), au(iii), zn(ii), pt(ii), ag(i), cu(ii), in(iii), hg(ii), and cd(ii), a correlation coefficient of r2 = 0.76 is found. this is a significan ... | 1985 | 4081779 |
| toxic impact of effluents from petrochemical industry. | the toxicity of effluents from a petrochemical industry center in southern finland was tested by conducting bioassays on organisms from three different trophic levels. in fish tests, rainbow trout (salmo gairdneri) were caged at the discharge site and simultaneously at a reference area. the only clear differences, among the measurements of 25 metabolic parameters, were observed in fish liver where activities of two detoxication enzymes were significantly increased in the exposed group. the water ... | 1985 | 3921341 |
| morphological and compositional changes in a planktonic bacterial community in response to enhanced protozoan grazing. | we analyzed changes in bacterioplankton morphology and composition during enhanced protozoan grazing by image analysis and fluorescent in situ hybridization with group-specific rrna-targeted oligonucleotide probes. enclosure experiments were conducted in a small, fishless freshwater pond which was dominated by the cladoceran daphnia magna. the removal of metazooplankton enhanced protozoan grazing pressure and triggered a microbial succession from fast-growing small bacteria to larger grazing-res ... | 1999 | 10049890 |
| environmental risk assessment for the widely used iodinated x-ray contrast agent iopromide (ultravist). | iodinated x-ray contrast media are diagnostic pharmaceuticals that are applied to enhance the contrast between organs or vessels examined and surrounding tissues during radiography. these substances are applied in doses up to ca. 200 g per person (corresponding to approx 100 g iodine) and are rapidly excreted. in the sewage system they contribute to the burden of adsorbable organic halogens (aox). to assess the potential environmental impact of this release, studies on environmental fate and eff ... | 1999 | 10090816 |
| [resistance of the alimentary canal of daphnia magna straus to the effect of enteropathogenic nag-vibrios]. | the interrelations between 30 daphnias and enteropathogenic nag-vibrios were experimentally investigated. using histological and immunoserological techniques, nag-vibrio administration into the medium inhabited by crustaceous was shown to cause no pathological changes in the animal alimentary canal. daphnias used these organisms as food. the intestinal epithelium is well protected from mechanical injury by peritrophic membrane, chitinous lining and peritrophic cavity where digestion takes place. | 1986 | 3756339 |
| acute toxicity of furazolidone on artemia salina, daphnia magna, and culex pipiens molestus larvae. | as a result of evidence of the ecotoxicity of nitrofurans, the acute toxicity of furazolidone was tested in vivo on two aquatic organisms, artemia salina and daphnia magna, which are both crustaceans. toxicity studies were also performed on larvae of culex pipiens molestus. results indicated a significant toxicity of the compound on culex pipiens and daphnia magna, while artemia salina proved to be the least sensitive. | 1988 | 3234296 |
| [toxic action of carbendazim on aquatic animals]. | the toxic effect of carbendazim was studied using as biologic indicators, lebistes reticulatus peters, asellus aquaticus racov and daphnia magna (cladocera) in the laboratory of human epidemiology and ecology in rzeszów. the experiments were done in crystallizers of from 150 ml capacity for aselius to 250 ml for young lebistes and in tubes of 30 ml capacity for daphnia. each experiment was done in triplicate with 10 animals in each repetition. the observation of carbendazim toxicity was carried ... | 1989 | 2637484 |
| bioavailability of benzo(a)pyrene and dehydroabietic acid from a few lake waters containing varying dissolved organic carbon concentrations to daphnia magna. | | 1990 | 2383683 |
| acute toxicity of the natural algicide, cyanobacterin, to daphnia magna. | cyanobacterin is a potent, photosynthetic inhibitor produced as a secondary metabolite by the filamentous, freshwater cyanobacterium scytonema hofmanni. with a spectrum of activity encompassing species of cyanobacteria and eucaryotic algae as well as higher plants, cyanobacterin might be utilized as a commercial algicide for algae waterbloom control. as a component of the preliminary environmental risk/hazard evaluation of this proposed application, the acute toxicity of cyanobacterin to the pla ... | 1990 | 2276362 |
| regression and cluster analysis of the acute toxicity of 267 chemicals to six species of biota and the octanol/water partition coefficient. | the acute toxicities of 267 compounds to six aquatic and one terrestrial species were investigated with correlation, principal component and cluster analysis techniques for relationships with each other and with the compounds' octanol/water partition coefficient. selection of the investigated chemicals was based on the availability of at least three of the following measured parameters: acute (24-h to 96-h) lethal concentrations (lc50) to the fish fathead minnow (pimephales promelas), the fish g ... | 1991 | 1815369 |
| qsar studies of comparative toxicity in aquatic organisms. | this study investigated the relationships between the toxicities of common organic pollutants to the fathead minnow (pimephales promelas), to daphnia magna, to tetrahymena pyriformis and in the microtox test, which uses the luminescent bacterium photobacterium phosphoreum. the toxicity data were compiled from the literature, with the exception of 40 experimentally determined microtox data. encouraging correlations are seen, indicating significant relationships between fish toxicities and those t ... | 1991 | 1815364 |
| use of bioassays for assessment of water-extractable ecotoxic potential of soils. | the characterization of contaminated soils is based on heterogeneous strategies considering chemical analyses or bioassays. in the report bioassays for soils, test methods which are at an advanced state of development and standardization are recommended by the german dechema (german society for chemical apparatus, chemical engineering and biotechnology e.v.). following this report six soil samples contaminated with different organic and inorganic substances are applied to bioassays using the fol ... | 2000 | 10702342 |
| [neutral and zwitterionic detergents: dependence of biological effectiveness on critical micellar concentration]. | the biological activity of various zwitterionic and nonionic detergents was studied as a function of the corresponding critical micellar concentration (cmc-values). the criteria chosen to measure biological activities were inhibition of bioluminescence, lysis and cell-killing of vibrio fischeri, hemolysis, and inhibition of daphnia magna. when zwittergent-detergents were studied in three different bioassays their biological activity increased with decreasing cmc-values. however, the biological a ... | 1992 | 1307831 |
| standard curves for nuvacron, malathion, sevin, ddt and kelthane tested against the mosquito culex pipiens l. and the microcrustacean daphnia magna straus. | the fourth instar larvae of culex pipiens l. and adults of microcrustacean daphnia magna straus were reared under standardized conditions and used as bioassay test organisms for the preparation of the standard log concentration--probit (lc--p) regression lines for each of the following pesticides: nuvacron, malathion, sevin, ddt and kelthane. when the above pesticides were tested against the larvae of c. pipiens, the lc50 values (in ppm) ranged as follows: nuvacron 0.0014--0.0019, malathion 0.00 ... | 1975 | 807992 |
| simple analogs of the toxin callicarpone. | callicarpone, a component 10 times as toxic to fish as rotenone, has been isolated from the leaves of callicarpa candicans. it is reasonable to assume that callicarpone will act as an insecticidal agent as does rotenone. therefore, the structure-activity relationship of callicarpone was examined by synthesizing a series of compounds having certain of its structural features. those compounds were tested for insecticidal and antimicrobial activities. a study of synthetic analogs elucidated the fun ... | 1979 | 501532 |
| [toxic effect of ddt, chlordane and water from the ignacio ramírez dam (mexico), on daphnia magna (crustacea: daphnidae)]. | chlorodiphenylnitrichloroethane (ddt) and chlordane (clo) are currently used in mexico to control malaria and termites. from 1990 to 1996 a total of 27 ton of ddt and 508 of clo were imported. we establish a methodology to determine their environmental impact in a mexican dam (ignacio ramírez). the toxic effect of ddt and clo were evaluated on the o-demethylase (od) and acethycholinesterase activities (acha) of the cladoceran daphnia magna exposed to different concentrations of the insecticides ... | 1999 | 11021309 |
| toxicity of methyl tertiary butyl ether to daphnia magna and photobacterium phosphoreum. | | 1995 | 8555689 |
| inter- and intra-laboratory testing of the daphnia magna iq toxicity test. | | 1996 | 8694887 |
| inhibition of acetylcholinesterase activity as effect criterion in acute tests with juvenile daphnia magna. | in this work we investigated the possibility of using the enzyme acetylcholinesterase (ache) activity in daphnia magna homogenates, both in vivo and in vitro conditions, as a specific method for rapid toxicity evaluations. the results from in vivo and in vitro ache inhibition tests were compared with 48 hours ec50 values obtained in conventional acute bioassays. ec50 values from in vivo ache inhibition tests were: 2.4 micrograms/l for parathion, 0.2 microgram/l for paraoxon; dca and cadmium at t ... | 1996 | 8867149 |
| use of a miniaturized test system for determining acute toxicity of toxicity identification evaluation fractions. | a miniaturized test system was developed and used to determine the acute toxicity of effluent fractions separated by hplc to daphnia magna and pimephales promelas. the miniaturized test system consists of exposing test organisms in 1 ml of test solution using 48-well microtiter plates for the test vessels. several factors were investigated to determine the acceptability of this test system. these factors included organism biomass to test solution ratio, toxicity of the microtiter plates to the o ... | 1996 | 8930499 |
| environmental health assessment of the benthic habitat adjacent to a pulp mill discharge. i. acute and chronic toxicity of sediments to benthic macroinvertebrates. | in this study, we assessed the acute and chronic toxicity of sediments contaminated by bleached kraft pulp mill effluent (bkme). sediments were collected in august 1991 and 1992, and may 1993 from eight stations exposed directly to the effluent and from four reference sites.acute toxicity was determined for five macroinvertebrates (hyalella azteca, daphnia magna, chironomus riparius, hexagenia spp., and tubifex tubifex) using pore water, elutriate, and bulk sediment exposures. chronic toxicity w ... | 1997 | 9096076 |
| assessment of the ecotoxic potential of soil contaminants by using a soil-algae test. | to assess the ecotoxic potential of soil contaminants, a test with the soil alga chlorococcum infusionum has been developed, enabling investigations of soil pollutions with soluble and fairly soluble chemicals. three soil types artificially contaminated with sb compounds and five soils from a historical mining area, which were highly polluted with sb, as, hg, and cu, were used as test soils. for antimony, ec50 values from 125 mg/kg up to > 1000 mg/kg, depending on soil type, were determined. two ... | 1998 | 9626553 |
| qsar study of the toxicity of benzoic acids to vibrio fischeri, daphnia magna and carp. | the toxicities of benzoic acids to vibrio fischeri, daphnia magna and carp were measured. the results showed that the toxicity to v. fischeri and daphnia decreased in the order of bromo > chloro > fluoro approximately equal to aminobenzoic acids. the toxicity of substituted benzoic acids to carp and daphnia was much lower that to v. fischeri. the results also showed that the toxicity of benzoic acids to daphnia decreased as the ph increased. it is suggested that ionized and non-ionized forms hav ... | 1998 | 9646529 |
| the toxicity of margosan-o, a product of neem seeds, to selected target and nontarget aquatic invertebrates | margosan-o, an insecticide formulated from extracts of neem tree (azadirachta indica) seed kernels, besides being toxic, also has feeding, oviposition-deterring, and growth-inhibitory effects on insects. this product, registered in the united states for ornamental plants, has been proposed for food crop use. however, little information exists on its effects on aquatic organisms. this study investigated toxicity of margosan-o to the mosquito culex spp., a possible target species, and to nontarget ... | 1998 | 9732473 |
| a new low-cost microbiotest with the protozoan spirostomum teres: culture conditions and assessment of sensitivity of the ciliate to 14 pure chemicals. | this paper defines the culture conditions of the ciliate spirostomum teres and assesses its sensitivity to some xenobiotics for the development of a new low-cost microbiotest. the model was selected for its ubiquitous distribution, large size for a unicellular species, easy culture in holoxenic medium, moderate generation time, and high sensitivity to pure toxicants. the influence of different culture waters, inocula of ciliates, food, temperature, light, and darkness on the growth of the ciliat ... | 1998 | 9799574 |
| effects of different protective agents on the phototoxicity of fluoranthene to daphnia magna. | some compounds, accumulated by organisms, are transformed into toxic forms when irradiated with uv light. the polycyclic aromatic hydrocarbon (pah) fluoranthene is one such compound of environmental importance. in this study on daphnia magna, fluoranthene toxicity increased significantly after a 2 h exposure to solar-simulating uv light, if organisms were allowed to accumulate the substance for 24 h prior to irradiation. since no enhanced toxicity was observed if the solutions were irradiated be ... | 1998 | 9827053 |
| toxicity-based criteria for the evaluation of textile wastewater treatment efficiency. | brazilian textile mills import wastewater treatment technologies, performances of which are generally evaluated only on a physicochemical basis. thus, a battery of bioassays was used to evaluate the performance of an ozonation system to treat textile effluents. comparative toxicological profiles for bacteria (vibrio fischeri), algae (scenedesmus subspicatus), daphnia (daphnia magna), fish (poecilia reticulata), and plants (soybean--glycine max, rice--oryza sativa, and wheat--triticum aestivum), ... | 2001 | 11345461 |
| identification of an enzymatically formed glutathione conjugate of the cyanobacterial hepatotoxin microcystin-lr: the first step of detoxication. | cyanobacterial toxins have adverse effects on mammals, birds and fish and are being increasingly recognised as a potent stress factor and health hazard factor in aquatic ecosystems. microcystins, cyclic heptapeptides and a main group of the cyanotoxins are mainly retained within the producer cells during cyanobacterial bloom development. however, these toxins are released into the surrounding medium by senescence and lysis of the blooms. any toxin present could then come into contact with a wide ... | 1998 | 9838216 |
| use of new microbiotests with daphnia magna and selenastrum capricornutum immobilized forms. | a preliminary assessment of toxicity to aquatic life of water from rice fields treated with pesticides, and particularly with the herbicides molinate and quinclorac, was performed from june to august 1996 in a rice paddy area integrated in a natural reserve. new rapid-screening microbiotests with daphnia magna and selenastrum capricornutum were used. water samples were collected from: a water source for irrigating the rice fields, two rice plots, a drainage channel and the river in which the wat ... | 1998 | 9839408 |
| altered cholinesterase and monooxygenase levels in daphnia magna and chironomus riparius exposed to environmental pollutants. | biochemical indices were investigated for their potential use as variables of sublethal toxicity in daphnia (cholinesterase) and chironomus (cholinesterase and biotransformation enzymes). parathion, dichlorvos, and aldicarb caused dose-related inhibition of cholinesterase (che) in 24-h bioassays with both species. ratios of daphnia and chironomus che ic50 values to corresponding immotility ec50 values derived from the same experiment covered the range 0.26 to 1.2. estimates of the che inhibition ... | 1999 | 9931232 |
| the toxicity and concentrations of pahs in creosote-contaminated lake sediment. | sediment samples, divided into three layers (0-10, 10-20 and 20-30 cm), were collected from 16 sites in lake jämsänvesi, central finland. the acute toxicity of pore waters and elutriates (sediment + water 1:4 v/v) were studied by bioluminescence inhibition test and by immobilisation of water fleas (daphnia magna straus). concentrations of polycyclic aromatic hydrocarbons (pahs) in sediments and elutriates were measured by gas chromatography using flame ionization detection (gc/fid). the highest ... | 1999 | 10028662 |
| quality assurance in aquatic biology--a user's perspective. | the essential elements of developing biological quality assurance systems are presented in terms of the 4m principles. these relate to methods, manpower, materials, and machines. the use of international or european standards is recommended where such standards exist. users must be sure that these are appropriate to their specific needs as standardisation can require considerable compromise. examples of limitations in international standards are given with reference to the coliform isolation by ... | 1998 | 10356849 |
| bioassay-directed identification of organic toxicants in river sediment in the industrial region of bitterfeld (germany)-a contribution to hazard assessment | bioassay-directed identification of toxicants in an acetonic extract of a sediment of the riverine spittelwasser in the industrial region of bitterfeld (germany) was conducted. for this purpose, a combination of chromatographical fractionation, chemical analysis, and a biotest battery including vibrio fischeri (inhibition of bioluminescence), daphnia magna (immobilization), and scenedesmus vacuolatus (inhibition of cell multiplication) was applied. major toxicants identified and confirmed were m ... | 1999 | 10398766 |
| bioassays for risk assessment of coal conversion products. | traditional as well as biotechnological processing of coal leads to complex mixtures of products. besides chemical and physical characterization, which provides the information for product application, there is a need for bioassays to monitor properties that are probably toxic, mutagenic or cancerogenic. investigations carried out focused on the selection, adaptation and validation of bioassays for the sensitive estimation of toxic effects. organisms like bacteria, daphnia magna and scenedesmus ... | 1999 | 10461379 |
| evaluation of acute toxicity and genotoxicity of liquid products from pyrolysis of eucalyptus grandis wood. | slow pyrolysis of eucalyptus grandis wood was performed in an oven laboratory, and smoke was trapped and condensed to yield liquid products. polycyclic aromatic hydrocarbons (pahs) and phenolic fractions were isolated from the former liquid products using adsorption column chromatography (acc) and identified by gc/ms. concentrations of pah and phenolic fractions in total pyrolysis liquids were respectively 48.9 microg/g and 8.59% (w/w). acute toxicity of total samples of pyrolysis liquids and th ... | 2000 | 10629278 |
| environmental risk assessment for the polycyclic musks, ahtn and hhcb. ii. effect assessment and risk characterisation. | reports of the polycyclic musks ahtn and hhcb in surface water and fish, primarily in europe, have prompted studies of their environmental effects. these effects then are used, along with the predicted environmental concentrations in a risk assessment according to the approach developed under european union regulation 793/93, in line with the technical guidance document for risk assessment of new and existing chemicals. in 72-h studies with algae (pseudokirchneriella subcapitata), noecs were 0.3 ... | 1999 | 10630704 |
| ecotoxicological evaluation of pig slurry. | swine sewage could be source of nutrients and pollutants. this work estimates the environmental risk in nine samples from different farm treatment systems based on the evaluation of their effects in daphnia magna acute test, and on the assessment of cu, zn and ammonia as main contributors. nh3 and cu were responsible for lc50 results (1-5% of dilution). organic compounds were quantified through several extraction methods (spmds, spe and solvent extraction). a more exhaustive extraction was perfo ... | 2000 | 11057690 |
| purification of vitellin from grass shrimp palaemonetes pugio, generation of monoclonal antibodies, and validation for the detection of lipovitellin in crustacea. | much effort has been put into developing vitellogenin antibodies against a wide variety of aquatic vertebrate species to study potential estrogen or anti-estrogen endocrine disrupters. little work has been done on endocrine disruption in aquatic invertebrates. although some antibodies have been produced against blue crab and penaeid shrimp lipovitellin, they have only poor cross-reactivity with the important estuarine grass shrimp, palaemonetes pugio. vitellin was purified from eggs, monoclonal ... | 2000 | 11083030 |
| influence of uv radiation on four freshwater invertebrates. | laboratory tests confirmed a negative and variable response of the following four species to artificial uv radiation: cypridopsis vidua, an ostracode; chironomus riparius, a midge larvae; hyalella azteca, an amphipod; and daphnia magna, a daphnid. severe damage occurred at uv-b irradiance ranging from 50 to 80% of incident summer values. under constant exposure to uv and photosynthetically active radiation (par) the acute lethal response was recorded at 0.3, 0.8, 0.8 and 4.9 w m-2 uv-b for d. ma ... | 2000 | 11107851 |
| acute toxicity of locust insecticides to two indigenous invertebrates from sahelian temporary ponds. | during desert locust plagues large amounts of insecticides are used for control operations. drift from these treatments and accidental overspraying may contaminate small surface waters such as temporary ponds. the present study describes methods for static acute toxicity tests with two abundant organisms that occur in temporary ponds in the african sahel region: the fairy shrimp streptocephalus sudanicus daday (branchiopoda, anostraca, streptocephalidae) and the backswimmer anisops sardeus herri ... | 2001 | 11161680 |
| the role of time as a quantifiable variable of toxicity and the experimental conditions when haber's c x t product can be observed: implications for therapeutics. | one hundred years ago, warren established for the first time a quantitative link between dose and time while studying the toxicity of sodium chloride in daphnia magna (straus). during this century, many toxicologists in different contexts returned to this idea, which has become known as haber's rule of inhalation toxicology. most attempts to explore this relationship ended in frustration because of the observed deviations from it, which were unfortunately called exceptions. thus, toxicologists c ... | 2001 | 11181890 |
| single and combined effects of sediment-associated pahs on three species of freshwater macroinvertebrates. | polycyclic aromatic hydrocarbons (pahs) are ubiquitous pollutants of sediments. sediment quality criteria often use toxicity data for individual pahs. however, pahs always occur in field sediments as a complex mixture of compounds. in this study, the toxicity of phenanthrene (p), fluoranthene (fla) and benzo(k)-fluoranthene (b), alone or in combination, was assessed using monospecific sediment tests of acute toxicity (between 24 h and 14 days). the test sediments were spiked formulated sediments ... | 2001 | 11759569 |
| fate and effect of monoalkyl quaternary ammonium surfactants in the aquatic environment. | the effect of the alkyl chain of quaternary ammonium-based surfactants on their aquatic toxicity and aerobic biodegradability has been studied. two families of monoalkylquats surfactants were selected: alkyl trimethyl ammonium and alkyl benzyl dimethyl ammonium halides. acute toxicity tests on daphnia magna and photobacterium phosphoreum were carried out and ec50 values in the range of 0.1-1 mg/l were obtained for the two series of cationic surfactants. although the substitution of a benzyl grou ... | 2001 | 11202711 |
| assessment of toxicity reduction after metal removal in bioleached sewage sludge. | sewage sludge can be applied to land to supply and recycle organic matter and nutrients. trace elements in sludge, however, may accumulate in the soil with repeated sludge applications. reducing metal content may therefore reduce the adverse effects of sludge application. the objective of this study was to evaluate the efficiency of bioleaching technology in reducing metal content and toxicity as measured by a battery of terrestrial and liquid-phase bioassays. sludge-soil mixtures simulating the ... | 2001 | 11317888 |
| factors influencing predictive models for toxicology. | comparisons of different models to predict toxicity and evaluation of the predictive power of a model are affected by the variability of the data. we assessed this problem by considering experimental toxicity data and chemical descriptors. we evaluated several toxicological end-points (oncorhynchus mykiss, daphnia magna, acceptable daily intake, anas platyrhynchos, colinus virginianus and muridae) in the case of pesticides and also considered the availability of toxicological data. we calculated ... | 2001 | 11813807 |
| phototactic behavior of daphnia and the continuous monitoring of water quality: interference of fish kairomones and food quality. | we carried out a laboratory study to evaluate the sensitivity of phototactic behavior of daphnia magna to sublethal concentrations of pentachlorophenol (pcp) and copper. more specifically, we determined whether the sensitivity of a d. magna clone to those pollutants is influenced by food quality and the presence of fish kairomones. test animals were fed either unicellular green algae (scenedesmus acutus) or fresh baker's yeast (saccharomyces cerevisiae) and were cultured in the presence or absen ... | 2001 | 11337874 |
| toxicity evaluation of metal plating wastewater employing the microtox assay: a comparison with cladocerans and fish. | the relative sensitivity of the microtox assay is closely related to the type of toxicant, and hence its utility in biomonitoring effluents is better evaluated on a case-by-case basis. the microtox assay, employing the marine bacterium vibrio fischeri, was evaluated for its applicability in monitoring metal plating wastewater for toxicity. the results of the microtox assay after 5, 15, and 30 min of exposure, were compared with data obtained from conventional whole effluent toxicity testing (wet ... | 2001 | 11339713 |
| toxicity tests to assess pollutants removal during wastewater treatment and the quality of receiving waters in argentina. | in argentina, legislation to control adverse impacts of effluent discharges and the quality of receiving waters is scant and relies mainly on the physicochemical characteristics of the effluents and receiving waters. objectives of this study were to use standardized acute toxicity tests to assess treatment of petrochemical industry effluents and the toxicity of various treated industrial effluents in the buenos aires metropolitan area and their receiving waters. tests for the first objective use ... | 2001 | 11409193 |
| the cause of parasitic infection in natural populations of daphnia (crustacea: cladocera): the role of host genetics. | disease patterns in nature may be determined by genetic variation for resistance or by factors, genetic or environmental, which influence the host-parasite encounter rate. elucidating the cause of natural infection patterns has been a major pursuit of parasitologists, but it also matters for evolutionary biologists because host resistance genes must influence the expression of disease if parasite-mediated selection is to occur. we used a model system in order to disentangle the strict genetic co ... | 2000 | 11416906 |
| the use of acute and chronic bioassays to determine the ecological risk and bioremediation efficiency of oil-polluted soils. | to compare the effectiveness of acute and chronic bioassays for the ecological risk assessment of polluted soils, soil samples from a site with an historical mineral oil contamination (< 50-3,300 mg oil/kg dry soil) at the petroleum harbour in amsterdam, the netherlands, were screened for ecological effects using acute and chronic bioassays. a two-step 0.001 m ca(no3)2 extraction at a final solution-to-soil ratio of 1:1 was used to prepare extracts for the acute bioassays. acute bioassays (< or ... | 2001 | 11434283 |
| incomplete ecdysis is an indicator of ecdysteroid exposure in daphnia magna. | daphnia magna were exposed for 21 d to the ecdysteroids, 20-hydroxyecdysone (20-e), the accepted molting hormone, and ponasterone a (poa), an ecdysteroid found in some crustaceans and many plants. daphnids were monitored for alterations in molting, fecundity, and survival time. the 20-e elicited no significant effects on molting frequency, and its significant effects on reproduction were only at concentrations (260 nm) associated with premature death caused by incomplete ecdysis. we also examine ... | 2001 | 11434299 |
| biodegradation of aliphatic-aromatic copolyesters: evaluation of the final biodegradability and ecotoxicological impact of degradation intermediates. | the biological degradation behaviour of the aliphatic-aromatic copolyester ecoflex was investigated with regard to the degree of degradation and the intermediates formed during the degradation process. the individual thermophilic strain thermomonospora fusca, isolated from compost material, was used for the degradation experiments in a defined synthetic medium at 55 degrees c. after 22 days of degradation more than 99.9% of the polymer had depolymerized and with regard to the degradation of the ... | 2001 | 11444312 |
| assessment of toxicity hazards of dredged lake sediment contaminated by creosote. | in order to predict the potential toxicity hazards of sediment remediation by dredging, an experimental laboratory simulation was made by investigating seven ratios of creosote-contaminated sediment (lake jämsänvesi, central finland) and artificial lake water mixtures. sediment was suspended in water at the ratios of 1:1, 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, 1:128 v/v. the elutriates were analysed for the acute toxicity by photoluminescence bacterial and waterflea (daphnia magna straus) tests. the c ... | 1999 | 10635593 |
| [the possibility of using daphnia magna as an alternative test object for evaluating the receptor selectivity of cholinotropic substances]. | the results of study of the selectivity of the effects of cholinonegative and cholinopositive agents obtained on daphnia magna hydrobionts were compared with the results of investigations on rats. this allowed daphnia to be recommended as an alternative test object for studying the selectivity of the effect of cholinotropic agents in relation to some subtypes of muscarine receptors in an intact organism. | 1999 | 10650521 |
| toxicity of a neem (azadirachta indica) insecticide to certain aquatic organisms. | neem based insecticides are likely to show a large increase in use in the near future. in the present work, the toxicity of a neem insecticide, neem-azal-t/s, was tested against the mosquito larvae, as well as against certain non target organisms occurring in a polluted pond and a shallow stream, located in a cultivated area in giza, egypt. samples of water containing the experimental animals were collected from this area, and toxicity tests were conducted in the laboratory by exposing them to a ... | 2000 | 10786033 |
| microbial and cod removal in a municipal wastewater treatment plant using coagulation flocculation process. | this study was designed to improve the removal efficiency of cod, ss, and microorganism at the s. giovanni a teduccio municipal wastewater treatment plant, naples, italy. the plant consists of screen, sand grinder, oil removal, coagulation, flocculation and sedimentation units, hypochlorite disinfection, mechanical dewatering, and thermal sludge conditioning. a series of jar-test was conducted on twelve samples taken after screen using feso4 alone or together with ca(oh)2 at 100 rpm rapid mixing ... | 2002 | 12369640 |
| acute toxicity test with daphnia magna: an alternative to mammals in the prescreening of chemical toxicity? | in this study, the association between the acute toxicity of 15 compounds to daphnia magna, expressed as 24- and 48-h lc(50) values, and the corresponding oral ld(50) values for the rat was tested. since there was evidence of a strong relationship between the two species, the sample was extended to 54 cases by including the values for acute toxicity to d. magna and rat of more chemicals published by other authors. thus, a total of 54 data points were further used to ascertain the relationship be ... | 2000 | 10903834 |
| ecotoxicological experiences on lemna minor test system. | are plants generally less sensitive to toxicity than aquatic animals as indicated by some authors (1)? the use of phytotoxicity (higher plant) tests as a part of ecotoxicology is relatively underdeveloped. the objective of this study was to compare the results of the oecd lemna growth inhibition test with other mainly used test systems. three toxicants were tested applying the alga growth inhibition test (seleneastrum capricornutum), the daphnia immobilization test (daphnia magna) and the microt ... | 2000 | 10943492 |
| comparison of four chronic toxicity tests using algae, bacteria, and invertebrates assessed with sixteen chemicals. | the performances of four chronic toxicity tests, comprising the daphnia magna 21-day (d) (crustacean), brachionus calyciflorus 2-d (rotifer), pseudokirchneriella subcapitata 72-h (green algae), and the microtox chronic 22-h (bacteria) tests, were compared. sixteen chemicals with toxicity covering 6 orders of magnitude were studied. very high correlations were found between the noec/ec(10) pseudokirchneriella 72-h, noec/ec(10) brachionus 2-d, and the noec daphnia 21-d tests. the toxicological res ... | 2000 | 11023697 |
| assessment of the influence of use on ecotoxicological characteristics of synthetic ester lubricants. | synthetic ester lubricants need optimisation about their technical and their ecotoxicological characteristics. to determine the ecotoxicological potential the required examinations can be based on the procedure for a risk assessment of chemicals. at present risk classification of lubricant oils is carried out with new oil fluids that are normally prepared before application in aqueous bioassays. in order to improve the ecotoxicological characteristics of some lubricant oils, the quality of the p ... | 2002 | 12463681 |
| a test battery for the ecotoxicological evaluation of pentachlorophenol. | experimental bioassays are currently used in ecotoxicology and environmental toxicology to provide information for risk assessment evaluation of new chemicals and to investigate their effects and mechanisms of action; in addition, ecotoxicological models are used for the detection, control and monitoring of the presence of pollutants in the environment. as a single bioassay will never provide a full picture of the quality of the environment, a representative, cost-effective and quantitative test ... | 2001 | 11566584 |
| tests for the toxicity assessment of cyanobacterial bloom samples. | cyanobacterial (blue-green algal) blooms are one of the common consequences of the increasing eutrophication of surface waters. the production of cyanobacterial toxins and their presence in drinking and recreational waters represents a growing danger to human and animal health. due to a lack of toxin standards and to resource limitations on the wide-scale use of analytical methods (e.g., high-performance liquid chromatography, enzyme-linked immunosorbent assay (elisa)) in cyanobacterial toxin mo ... | 2001 | 11594024 |
| the toxicities of a polyunsaturated fatty acid and a microcystin to daphnia magna. | polyunsaturated fatty acids (pufas) are essential components of zooplankton diets. however, studies with pufas from cyanobacteria indicate toxic properties. we investigated the toxicity of the pufa gamma-linolenic acid and the cyanobacterial peptide toxin microcystin-lr to daphnia. the pufa was acutely toxic at a concentration of 9 micrograms ml-1. the effect of microcystin-lr was not statistically significant at the concentration used (3 micrograms ml-1), but an additive effect with the pufa wa ... | 2001 | 11594032 |
| degradation in soil and water and ecotoxicity of rimsulfuron and its metabolites. | the degradation and ecotoxicity of sulfonylurea herbicide rimsulfuron and its major metabolites were examined in batch samples of an alluvial sandy loam and in freshwater. an hplc-dad method was adapted to simultaneously identify and quantify rimsulfuron and its metabolites, which was successfully validated by gc-ms analysis. in aqueous solutions, pure rimsulfuron was rapidly hydrolyzed into metabolite 1 (n-(4,6-dimethoxypyrimidin-2-yl)-n-(3-(ethylsulfonyl)-2-pyridinylurea)), which itself was tr ... | 2001 | 11680747 |
| ecotoxicological study of lithuanian and estonian wastewaters: selection of the biotests, and correspondence between toxicity and chemical-based indices. | the toxicity of industrial and urban wastewater (ww) samples collected in lithuania and estonia was evaluated by using a suite of biological tests comprising the algaltoxkit f with selenastrum capricornutum, the charatox with nitellopsis obtusa, daphtoxkit f with daphnia magna, thamnotoxkit f with thamnocephalus platyurus, protoxkit f with tetrahymena thermophila and the microtox with vibrio fischeri. the charatox and thamnotoxkit f tests showed highest relative sensitivity, responding to 80-90% ... | 2003 | 12615419 |
| evaluation of bioassays versus contaminant concentrations in explaining the macroinvertebrate community structure in the rhine-meuse delta, the netherlands. | it is often assumed that bioassays are better descriptors of sediment toxicity than toxicant concentrations and that ecological factors are more important than toxicants in structuring macroinvertebrate communities. in the period 1992 to 1995, data were collected in the enclosed rhine-meuse delta, the netherlands, on macroinvertebrates, sediment toxicity, sediment contaminant concentrations, and ecological factors. the effect of various groups of pollutants (polycyclic aromatic hydrocarbons, tra ... | 2001 | 11764175 |
| partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. | the partitioning, bioavailability, and toxicity of cypermethrin in water-sediment systems was investigated. cypermethrin adsorbed extensively and rapidly, with an overall mean organic carbon (oc) adsorption partition coefficient (koc) of 350,000, and approximately 99% adsorption occurred within 24 h. bioavailability was measured via body burdens of daphnia magna and chironomus tentans. mean biota-sediment accumulation factors (bsafs), that is, the concentration in the organism as a proportion of ... | 2002 | 11808535 |
| study on quantitative structure-toxicity relationships of benzene derivatives acting by narcosis. | hydrophobicity (logp) as well as quantiative structure-toxicity relationships (qstrs) of some benzene derivatives acting by narcosis have been established based on narcotic mechanisms of action and toxicity data to the fathead minnow, daphnia magna and vibrio fischeri using information-theoretic topological index (id). excellent results are obtained in multiparametric regression upon introduction of dummy parameters (indicator variables). consistent increase in r(2)(a) values indicated that insp ... | 2002 | 11937334 |
| strong inbreeding depression in a daphnia metapopulation. | the deleterious effects of inbreeding have long been known, and inbreeding can increase the risk of extinction for local populations in metapopulations. however, other consequences of inbreeding in metapopulations are still not well understood. here we show the presence of strong inbreeding depression in a rockpool metapopulation of the planktonic freshwater crustacean daphnia magna, which reproduces by cyclical parthenogenesis. we conducted three experiments in real and artificial rockpools to ... | 2002 | 11989682 |
| [daphnia magna for studies of cholinergic preparations]. | published data and original experimental results are summarized to justify biochemically the use of daphnia magna straus as an additional or alternative test object for the study of cholinotropic substances. the data of radioligand analysis provide direct evidence that the organism of daphnia contains m-cholinoreceptors identical (with respect to pharmacodynamic parameters) to those in the human and animal organism. | 2002 | 12025794 |
| aquatic toxicity of triclosan. | the aquatic toxicity of triclosan (tcs), a chlorinated biphenyl ether used as an antimicrobial in consumer products, was studied with activated-sludge microorganisms, algae, invertebrates, and fish. triclosan, a compound used for inhibiting microbial growth, was not toxic to wastewater microorganisms at concentrations less than aqueous solubility. the 48-h daphnia magna median effective concentration (ec50) was 390 microg/l and the 96-h median lethal concentration values for pimephales promelas ... | 2002 | 12109732 |
| the use of a daphnia magna bioassay for rapid screening of acute intoxications with insecticides in dogs and cats. | sudden death due to acute insecticide intoxications occurs frequently in dogs and cats. the absence of characteristic lesions at autopsy often renders post-mortem diagnosis dependent on the analysis of samples taken from the carcase at autopsy. in the present study, a bioassay utilizing daphnia magna was proposed and tested as a rapid screening method for acute intoxications in dogs and cats. the bioassay was shown to be highly sensitive for detecting carbamate and organophosphate insecticides i ... | 2001 | 11469513 |
| genetic variation in a host-parasite association: potential for coevolution and frequency-dependent selection. | models of host-parasite coevolution assume the presence of genetic variation for host resistance and parasite infectivity, as well as genotype-specific interactions. we used the freshwater crustacean daphnia magna and its bacterial microparasite pasteuria ramosa to study genetic variation for host susceptibility and parasite infectivity within each of two populations. we sought to answer the following questions: do host clones differ in their susceptibility to parasite isolates? do parasite isol ... | 2001 | 11475049 |
| acute and chronic toxicity of dimethylsulfoxide to daphnia magna. | | 2003 | 12756470 |
| temporal patterns of genetic variation for resistance and infectivity in a daphnia-microparasite system. | theoretical studies have indicated that the population genetics of host-parasite interactions may be highly dynamic. with parasites perpetually adapting to common host genotypes and hosts evolving resistance to common parasite genotypes. the present study examined temporal variation in resistance of hosts and infectivity of parasites within three populations of daphnia magna infected with the sterilizing bacterium pasteuria ramosa. parasite isolates and host clones were collected in each of two ... | 2001 | 11475050 |