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The present study aimed to update the state of knowledge and attitudes of teachers concerning gifted students and their educational needs in the Netherlands. Additionally, this study aimed to gain insights into teachers' professional development (PD) needs regarding giftedness, taking teachers' knowledge and attitudes concerning this topic into account. A questionnaire was filled out by 116 teachers from thirteen elementary schools in the Netherlands. Teachers seemed to have little knowledge about how to identify and support gifted students. Their overall attitude was positive, however, teachers held negative or ambivalent attitudes towards ability grouping and acceleration. All teachers were interested in receiving PD, although teachers who had the most knowledge and most positive attitude were most interested. Teachers reported the most need for PD activities that do not require too much time and take place at their workplace. However, teachers' knowledge and attitude related positively to PD activities that require a greater time investment. The findings of the present study underline the importance of PD for teachers concerning giftedness. Future research is needed to effectively design and incorporate PD activities for teachers which meet their knowledge, attitudes, and PD needs. This eventually contributes to better education for gifted students.

The present study aimed to update the state of knowledge and attitudes of teachers concerning gifted students and their educational needs in theNetherlands. Additionally, this study aimed to gain insights into teachers' professional development (PD) needs regarding giftedness, taking teachers' knowledge and attitudes concerning this topic into account. Aquestionnaire was filled out by 116 teachers from thirteen elementary schools in the Netherlands. Teachers seemed to have little knowledgeabout how to identify and support gifted students. Their overall attitude was positive, however, teachers held negative or ambivalent attitudestowards ability grouping and acceleration. All teachers were interested in receiving PD, although teachers who had the most knowledge and most positive attitude were most interested. Teachers reported the most need for PD activities that do not require too much time and take place at their workplace. However, teachers' knowledge and attitude related positively to PD activities that require a greater time investment. The findings of the present study underline the importance of PD for teachers concerning giftedness. Future research is needed to effectively design and incorporate PD activities for teachers which meet their knowledge,attitudes, and PD needs. This eventually contributes to better education for gifted students. [ABSTRACT FROM AUTHOR]

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This study evaluated the effectiveness of an 8-week mindfulness training for children aged 8-12 with ADHD and parallel mindful parenting training for their parents. Parents ( N = 22) completed questionnaires on their child's ADHD and ODD symptoms, their own ADHD symptoms, parenting stress, parental overreactivity, permissiveness and mindful awareness before, immediately after the 8-week training and at 8-week follow-up. Teachers reported on ADHD and ODD behavior of the child. A within-group waitlist was used to control for the effects of time and repeated measurement. Training was delivered in group format. There were no significant changes between wait-list and pre-test, except on the increase of teacher-rated ODD behavior. There was a significant reduction of parent-rated ADHD behavior of themselves and their child from pre-to posttest and from pre- to follow-up test. Further, there was a significant increase of mindful awareness from pre-to posttest and a significant reduction of parental stress and overreactivity from pre-to follow-up test. Teacher-ratings showed non-significant effects. Our study shows preliminary evidence for the effectiveness of mindfulness for children with ADHD and their parents, as rated by parents. However, in the absence of substantial effects on teacher-ratings, we cannot ascertain effects are due to specific treatment procedures. [ABSTRACT FROM AUTHOR]

The aryl hydrocarbon receptor (AhR) receives much attention for its role in the toxicity of dioxins and dioxin-like polychlorinated biphenyls. However, many other compounds have also been reported to bind and activate AhR, of which natural food components are of special interest from a human health perspective. Using the dioxin receptor-chemical-activated luciferase gene expression (DR CALUX®) bioassay, extracts from many food items frequently consumed in the Netherlands were screened to estimate the intake of natural AhR agonists (NAhRAs). Using the prototypical AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as standard, it was estimated that the daily intake of NAhRAs might be considerably higher than the reported intake of dioxins and dioxin-like polychlorinated biphenyls. Potatoes, cruciferous vegetables, bread, hamburgers, and grapefruit juice contained most NAhRAs. Food preparation and acid treatment can show a significant effect on AhR activation. The interaction of natural and xenobiotic AhR agonists should be taken into account when performing risk-benefit analysis of both types of compounds. [ABSTRACT FROM AUTHOR]

Abstract: Overviews of levels of n-dibutylphthalate (DBP) and di(2-ethylhexyl)phthalate (DEHP) found in freshwater, marine water, sediment, and fish in the Netherlands are given. Sampling spanned a 9-month period (all seasons except winter) and allowed assessing whether phthalate levels are season dependent. Results obtained are compared to data reported for other Western European countries and a fugacity-based modeling approach is used to assess whether there is equilibrium among the various compartments. Highest levels of dissolved DBP and DEHP were found in freshwater samples, whereas these compounds were usually below the limit of detection (LOD) in marine water and sediment. Median levels were log-normally distributed; statistical analysis showed that sampling season is not a relevant determinant parameter. Similar results were obtained for the freshwater sediment compartment, with DEHP levels exceeding concentrations of DBP. DBP levels in fish were often below the LOD. Nevertheless, mean values around 1.8μgkg−1 wet fish were found for both DEHP and DBP. Fugacity calculations revealed that especially for DEHP there is no equilibrium among the compartments. DEHP emissions are directed to water, whereas the calculations reveal that sediments provide a sink for DEHP and there is net transport to air. Although it has been suggested that water is the primary compartment for DBP, fugacity plots suggest that air is the compartment to which emissions are directed dominantly. The data reported are in line with values found in Western Europe. [Copyright &y& Elsevier]

Understanding metal bioavailability of plants in soils requires, apart from physiological processes and symbiosis with arbuscular mycorrhizal fungi, the consideration of the chemical availability in the soil solution (the intensity of the toxic exposure) and the soil's capacity to supply the metal (capacity). In this contribution we report on the time-dependent accumulation of As, Cd, Cr, Cu, Ni, Pb, and Zn in lettuce (Lactuca sativa L.). Bioassays with 17 Dutch field soils and two artificially metal-contaminated soils were carried out. Phytotoxicity was observed in soils with pH (pore water) <4.8. Metal uptake is shown to be both metal- and soil-dependent and strongly depends on the amount of water the plant transpired and the available concentration in the water. No net accumulation of As, Pb, Ni, and especially Cr was observed in most soils tested. The latter observation is in agreement with findings of Zayed et al. (Planta, 1998 206:293–299), who reported that translocation of Cr from roots to shoots is extremely limited. Internal Cd levels in the plants varied greatly among soils, whereas plant tissue concentrations of Zn and especially Cu appear to be regulated at more or less fixed levels. The 0.01 M CaCl2-extractable metal pool provides the best descriptor for the capacity of the soil to supply Cd and Zn. This enabled the development of models that are suited to predict Zn and Cd uptake by lettuce in both field soils (weathered soils) and soils to which metal salts were added, which is common practice in toxicity testing of chemicals. It is concluded that of all metals included in this study, Cd is the metal of most concern due to bioaccumulation through the soil-plant-animal food chain as Cd is the only metal that might pose human or animal health risks at plant tissue concentrations that are not directly phytotoxic. Finally, application of the models for risk assessment purposes is discussed. [ABSTRACT FROM AUTHOR]

Abstract: In the Netherlands, risk assessment of contaminated soils is based on determining the total contaminant concentration. If this measured soil concentration exceeds the Soil Quality Standards (SQS) a higher tier risk evaluation must be performed. Experiences from the field have given rise to the perception that performing risk evaluations based on (measured) total concentrations may lead to an inaccurate assessment of the actual risks. Assuming that only the bioavailable fraction is capable of exerting adverse effects in the soil ecosystem, it is suggested, that by taking bioavailability into account in a (higher tier) risk evaluation, a more effect-based risk assessment can be performed. Bioavailability has been a subject of research for several decades. However up to now bioavailability has not been implemented in the Dutch Soil Quality Assessment Framework. First actions were taken in the Netherlands to determine whether the concept of bioavailability could be implemented in the risk assessment of contaminated soils and to find out how bioavailability can become part of the Dutch Soil Quality Assessment Framework. These actions have led to a concrete proposal for implementation of bioavailability methods in the risk assessment of organic contaminants in soils. This paper focuses on the chemical prediction of bioavailability for ecological risk assessment of contaminated soils. [Copyright &y& Elsevier]

The equilibrium partitioning method (EqP-method) can be used to calculate soil quality standards (expressed in mg/kg) from aquatic quality standards (expressed in μg/l) using a partitioning coefficient. The validity of this application of the EqP-method was studied comparing aquatic with terrestrial toxicity data. The data set collected for deriving environmental quality standards in the Netherlands, was used for this study. For 10 organic substances (chlorpyrifos, atrazine, carbofuran, pentachlorophenol, chlordane, aldrin, trichlorobenzene, heptachlor, trichlorophenol and trichloroethene) and for 8 metals, sufficient data were available. The aquatic toxicity data were multiplied by the partitioning coefficient in order to obtain aquatic data expressed in mg/kg. For some compounds the terrestrial toxicity data were significantly higher than the aquatic data but for other compounds it was the other way around. These differences indicate that the EqP-method can give significant over-or underestimations, due to inaccurate partitioning coefficients or differences in species sensitivities.These over- or underestimations can have an impact on the setting of environmental quality standards which are based on the hazardous concentration 5% (HC5) values. The uncertainty in the calculation of HC5 values attributed to the use of the EqP-method, was quantified. The HC5 values derived using the EqP-method were in 5% of the cases more than 20 times higher than the corresponding HC5 values that were derived directly from soil toxicity tests. Despite of this uncertainty the use of the EqP-method can still be advocated for setting soil quality guidelines when only a very limited number of terrestrial toxicity data are available. [Copyright &y& Elsevier]

Abstract: An extensive study was carried out in the Netherlands on the occurrence of a number of estrogenic compounds in surface water, sediment, biota, wastewater, rainwater and on the associated effects in fish. Compounds investigated included natural and synthetic hormones, phthalates, alkylphenol(ethoxylate)s and bisphenol-A. The results showed that almost all selected (xeno-)estrogens were present at low concentrations in the aquatic environment. Locally, they were found at higher levels. Hormones and nonylphenol(ethoxylate)s were present in concentrations that are reportedly high enough to cause estrogenic effects in fish. Field surveys did not disclose significant estrogenic effects in male flounder (Platichthys flesus) in the open sea and in Dutch estuaries. Minor to moderate estrogenic effects were observed in bream (Abramis brama) in major inland surface waters such as lowland rivers and a harbor area. The prevalence of feminizing effects in male fish is largest in small regional surface waters that are strongly influenced by sources of potential hormone-disrupting compounds. High concentrations of plasma vitellogenin and an increased prevalence of ovotestes occurred in wild male bream in a small river receiving a considerable load of effluent from a large sewage treatment plant. After employing in vitro and in vivo bioassays, both in situ and in the laboratory, we conclude that in this case hormones (especially 17α-ethynylestradiol) and possibly also nonylphenol(ethoxylate)s are primarily responsible for these effects. [Copyright &y& Elsevier]

Abstract: The river floodplain ‘Afferdense and Deestsche Waarden’ (ADW) in The Netherlands is diffusely contaminated with several heavy metals. It is, however, unclear whether this mixed contamination exerts any adverse ecotoxicological effects. In November 2000 and May 2001 a field survey was conducted in two areas in the ADW to collect a wide range of data concerning contamination levels, bioavailability, enchytraeids and earthworms and abiotic factors such as lutum and organic matter content, cation exchange capacity (CEC) and soil nutrient concentrations. Earthworms and enchytraeids were also analyzed for heavy metal content. At both sites arsenic and zinc were present in soil at relatively high concentrations (above the Dutch intervention value). In the two areas, both enchytraeids and earthworms accumulated metals. Fridericia ulrikae accumulated more cadmium than Enchytraeus buchholzi and Henlea perpusilla. The earthworm Lumbricus rubellus accumulated larger concentrations of Cr, Cu and Pb than Aporrectodea caliginosa and Allolobophora chlorotica. Dietary, physiological and behavioral characteristics may have contributed to these differences. [Copyright &y& Elsevier]