Individual-based model of Chironomus riparius population dynamics over several generations to explore adaptation following exposure to uranium-spiked sediments.

Natural populations are chronically exposed to various pollutants over many generations. It is thus crucial to understand and quantify adaptive dynamics of stressed populations in order to increase the relevance of ecotoxicological risk assessment. However, long-term consequences to population exposure are not much studied yet. The present study investigated evolutionary responses of Chironomus riparius populations exposed to uranium (heavy metal pollutant) and to assess the underlying mechanisms. To fulfil our objective, we produced data with organisms exposed to four relevant concentrations of uranium through eight successive generations. We built an individual-based (IBM) model of C. riparius population dynamics to analyse these data and to test several assumptions about the mechanisms involved in the phenotypic changes. The IBM was based on a dynamic energy budget (DEB) model for C. riparius by Pery et al. (2002). DEB models account mathematically for the acquisition and use of energy to describe and predict growth, maintenance, development and reproduction of living organisms. The IBM accounted for the influence of the test conditions on the observations over eight generations and highlighted some trait evolution such as time to emergence and adult size in control conditions. The model was then used to analyse the exposed population data. Our results showed that exposure to uranium led to a phenotypic selection via a differential survival characterised by longer time to emergence and smaller larval maximal size. As a general conclusion, IBMs based on DEB-based modelling developed to analyse multi-generation experiments are very promising for understanding and quantifying long term selection and tolerance mechanisms in a population under toxic stress.

Exposure of Chironomus riparius larvae to uranium: effects on survival, development time, growth, and mouthpart deformities.

Among non-biologically essential metals, data concerning uranium effects on freshwater benthic macroinvertebrates are scarce. The effects of uranium on survival, development time, growth and mouthpart deformities of midge Chironomus riparius were investigated. A 10-day static laboratory bioassay was performed exposing first instar larvae to artificial sediment spiked with four concentrations of uranium (2.97; 6.07; 11.44; 23.84 microg U g(-1) dry wt). As uranium was released from the sediment to the overlying water during this bioassay, both the sediment and the water column act as contamination pathways in giving rise to the observed effects. Significant negative effects on survival, development time, and growth were detected at 6.07, 6.07 and 2.97 microg U g(-1) dry wt, respectively. An LC20 of 2.49 microg U g(-1) dry wt (95% CI=1.48-4.27), and an LC50 of 5.30 microg U g(-1) dry wt (95% CI=3.94-7.25) were estimated. With respect to effects of uranium on larvae mouthpart deformities, we found that the lower the concentrations, the higher the deformity rates. These results highlight the potential impact of uranium at population level in environmentally realistic concentrations.

Análise Psicodramática: Teoria da Programaçäo Cenestésica / Psychodramatic analysis: theory of the programation Kenestesic

Este livro traz uma proposta teórica sobre o desenvolvimento psicológico do ser humano tendo como base as teorias do Psicodrama e as observaçöes clínicas do autor. Trata-se de uma sistematizaçäo das condutas e procedimentos a serem tomados durante uma psicoterapia, tanto para a abordagem intrapsiquica como relacional. O autor sistematiza ainda os procedimentos para trabalhar as contradiçöes justificadas, as defesas intrapsiquicas e os vínculos compensatórios

Análise Psicodramática: Teoria da Programação Cenestésica

Este livro traz uma proposta teórica sobre o desenvolvimento psicológico do ser humano tendo como base as teorias do Psicodrama e as observações clínicas do autor. Trata-se de uma sistematização das condutas e procedimentos a serem tomados durante uma psicoterapia, tanto para a abordagem intrapsiquica como relacional. O autor sistematiza ainda os procedimentos para trabalhar as contradições justificadas, as defesas intrapsiquicas e os vínculos compensatórios.