Repeated Measures Designs

Paine, Michael D.

doi:10.1897/1551-5028(1996)015<1439:rmd>2.3.co;2

Cited by 21 publications

(22 citation statements)

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“…The number of live insects per experimental unit was subjected to repeated-measures (multivariate) analysis of variance because determination of insect numbers per plant was carried out on the same plots at each evaluation date, 34,35 thereby avoiding the problem of pseudoreplication in time. 35 -37 This analysis was carried out using the PROC MANOVA procedure with the PROFILE statement, as suggested by von Ende. 38 When necessary, post hoc Tukey's HSD tests ( = 0.05) were performed to compare treatment means.…”

Section: Discussionmentioning

confidence: 99%

Competition between the phytophagous stink bugs Euschistus heros and Piezodorus guildinii in soybeans

Tuelher

Silva

Hirose

et al. 2016

Pest Management Science

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Section: Discussionmentioning

confidence: 99%

Competition between the phytophagous stink bugs Euschistus heros and Piezodorus guildinii in soybeans

Tuelher

Silva

Hirose

et al. 2016

Pest Management Science

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“…In experiment I, the same variable (egestion rate) was measured repeatedly over the test periods for each replicate using analysis of variance (ANOVA) [18,19]. The sphericity assumption of a test was checked with Mauchly's test.…”

Section: Statisticsmentioning

confidence: 99%

Relationship Between Reproduction, Sediment Type, and Feeding Activity of Lumbriculus Variegatus (Müller): Implications for Sediment Toxicity Testing

Leppänen¹,

Kukkonen²

1998

Environ Toxicol Chem

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The impact of reproduction and its interaction with sediment type on feeding activity of Lumbriculus variegatus are important because one major pathway in bioaccumulation of hydrophobic sediment-associated contaminants takes place through ingested sediment. In this study, the surface egesting behavior and the reproduction of the oligochaete were studied to understand this relationship and to give recommendations for the use of L. variegatus in sediment toxicity testing. Single individuals were used as replicates allowing proper control of reproduction behavior and egestion rate. Reproduction, growth, and egestion rates were clearly different in the two fine-grained unpolluted lake sediments used in the first 28-d experiment. The feeding of oligochaetes stopped during the reproduction process in the second 30-d experiment. Individuals divided at their middle; the anterior part took 2 d and the posterior part took 6 to 7 d to regenerate new segments and to initiate egestion. Culture conditions determined at what size the animals were able to reproduce during the test. In our tests 9 mg wet weight was the approximate minimum organism size needed for reproduction behavior. Recommendations for sediment toxicity and bioaccumulation testing using L. variegatus include using the largest oligochaetes in culture if reproduction is the endpoint and using recently fragmented individuals with complete segments if animals are employed in bioaccumulation tests.

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“…The BSAFs based on accumulation kinetics (k s /k e ) were tested by the Z-test applied procedure as described by Bailer et al [29]. The differences in egestion rates were measured using univariate repeated-measures analyses of variance [30] with SPSS 11.0. The sphericity assumption of the test was checked by Mauchly's test.…”

Section: Statisticsmentioning

confidence: 99%

Influence of sediment ingestion and exposure concentration on the bioavailable fraction of sediment‐associated tetrachlorobiphenyl in oligochaetes

Sormunen

Leppänen

Kukkonen

2008

Enviro Toxic and Chemistry

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The desorption and bioavailability of 3,3',4,4'-tetrachlorobiphenyl (PCB 77) were studied in spiked natural sediments at six concentrations. The desorption kinetics were measured in a sediment-water suspension using Tenax resin extraction, and the bioavailability was measured by exposing Lumbriculus variegatus (Oligochaeta) to PCB 77-spiked sediment in a 14-d kinetic study. In addition, freely dissolved pore-water concentrations were measured using the polyoxymethylene solid-phase extraction method. The present study examined whether bioavailability can be defined more accurately by measuring the size of desorbing fractions and the pore-water concentrations than by using the standard equilibrium partitioning approach. The importance of ingested sediment in bioaccumulation also was investigated. Our data showed a clear, decreasing trend in the rapid-desorbing fractions and in the standard biota-sediment accumulation factors (BSAF) with increasing concentration in sediment. Desorbing fractions-refined BSAFs were more uniform across the concentration treatments, and the pore-water PCB 77 concentration predicted tissue concentrations close to observed values. In the risk assessment process, pore-water concentration or desorbing fractions would lead to more precise bioavailability estimates compared with those from the traditional equilibrium partitioning approach. The result also showed, however, that sediment-ingesting worms had access to an additional bioavailable chemical fraction that was especially evident when PCB 77 pore-water concentrations most likely approached the solubility limit. Thus, feeding may modify the bioavailable fraction that cannot be explained by simple equilibrium partitioning models.

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Repeated Measures Designs

Cited by 21 publications

References 0 publications

Competition between the phytophagous stink bugs Euschistus heros and Piezodorus guildinii in soybeans

Competition between the phytophagous stink bugs Euschistus heros and Piezodorus guildinii in soybeans

Relationship Between Reproduction, Sediment Type, and Feeding Activity of Lumbriculus Variegatus (Müller): Implications for Sediment Toxicity Testing

Influence of sediment ingestion and exposure concentration on the bioavailable fraction of sediment‐associated tetrachlorobiphenyl in oligochaetes

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