633 research outputs found

    La place des cours de recherche dans la formation des enseignants du degré primaire

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    Ce mémoire professionnel vise à s’interroger quant à la place qu’occupent les cours de recherche dans le cursus de formation des futurs enseignants du degré primaire étudiant à la HEP-BEJUNE. Depuis la création des Hautes Ecoles Pédagogique en lieu et place des Ecoles normales, une dimension réflexive et scientifique fut introduite au sein des plans de cours, ceci afin de permettre aux étudiants d’adopter des postures critiques et objectives et à identifier et définir des problématiques pertinentes. Le cadre théorique tend tout d’abord à cerner la problématique en s’intéressant tant au cadre légal qui entoure la formation des enseignants qu’aux théories scientifiques qui mettent l’accent sur le caractère indispensable d’une interaction permanente entre théorie et pratique. Il s’agit, par la suite, de savoir si la recherche possède un impact sur la pratique quotidienne des enseignants ayant étudié à la HEP-BEJUNE. La méthodologie consistait ainsi à soumettre un questionnaire aux enseignants du Jura bernois et de la Bienne romande. Nous découvrons, entre autre, que, si une majorité des participants interrogés admettent que, lors de leur formation, ils n’arrivaient pas ou peu à lui reconnaître une quelconque légitimité, il est intéressant de relever qu’ils ne remettent pas nécessairement la recherche en question

    Sex differences in urinary levels of several biological indicators of exposure: a simulation study using a compartmental based toxicokinetic model

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    Toxicokinetic modeling is a useful tool to describe or predict the behavior of a chemical agent in the human or animal organism. A general model based on four compartments was developed in a previous study in order to quantify the effect of human variability on a wide range of biological exposure indicators. The aim of this study was to adapt this existing general toxicokinetic model to three organic solvents, which were methyl ethyl ketone, 1-methoxy-2-propanol and 1,1,1,-trichloroethane, and to take into account sex differences. We assessed in a previous human volunteer study the impact of sex on different biomarkers of exposure corresponding to the three organic solvents mentioned above. Results from that study suggested that not only physiological differences between men and women but also differences due to sex hormones levels could influence the toxicokinetics of the solvents. In fact the use of hormonal contraceptive had an effect on the urinary levels of several biomarkers, suggesting that exogenous sex hormones could influence CYP2E1 enzyme activity. These experimental data were used to calibrate the toxicokinetic models developed in this study. Our results showed that it was possible to use an existing general toxicokinetic model for other compounds. In fact, most of the simulation results showed good agreement with the experimental data obtained for the studied solvents, with a percentage of model predictions that lies within the 95% confidence interval varying from 44.4 to 90%. Results pointed out that for same exposure conditions, men and women can show important differences in urinary levels of biological indicators of exposure. Moreover, when running the models by simulating industrial working conditions, these differences could even be more pronounced. In conclusion, a general and simple toxicokinetic model, adapted for three well known organic solvents, allowed us to show that metabolic parameters can have an important impact on the urinary levels of the corresponding biomarkers. These observations give evidence of an interindividual variablity, an aspect that should have its place in the approaches for setting limits of occupational exposure

    Assessing Human Eye Exposure to UV Light: A Narrative Review.

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    Exposure to ultraviolet light is associated with several ocular pathologies. Understanding exposure levels and factors is therefore important from a medical and prevention perspective. A review of the current literature on ocular exposure to ultraviolet light is conducted in this study. It has been shown that ambient irradiance is not a good indicator of effective exposure and current tools for estimating dermal exposure have limitations for the ocular region. To address this, three methods have been developed: the use of anthropomorphic manikins, measurements through wearable sensors and numerical simulations. The specific objective, limitations, and results obtained for the three different methods are discussed

    ART, Stoffenmanager, and TRA: a systematic comparison of exposure estimates using the TREXMO translation system

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    Several occupational exposure models are recommended under the EU's REACH legislation. Due to limited availability of high-quality exposure data, their validation is an ongoing process. It was shown, however, that different models may calculate significantly different estimates and thus lead to potentially dangerous conclusions about chemical risk. In this paper, the between-model translation rules defined in TREXMO were used to generate 319000 different in silico exposure situations in ART, Stoffenmanager, and ECETOC TRA v3. The three models' estimates were computed and the correlation and consistency between them were investigated. The best correlated pair was Stoffenmanager-ART (R, 0.52-0.90), whereas the ART-TRA and Stoffenmanager-TRA correlations were either lower (R, 0.36-0.69) or no correlation was found. Consistency varied significantly according to different exposure types (e.g. vapour versus dust) or settings (near-field versus far-field and indoors versus outdoors). The percentages of generated situations for which estimates differed by more than a factor of 100 ranged from 14 to 97%, 37 to 99%, and 1 to 68% for Stoffenmanager-ART, TRA-ART, and TRA-Stoffenmanager, respectively. Overall, the models were more consistent for vapours than for dusts and solids, near-fields than for far-fields, and indoor than for outdoor exposure. Multiple linear regression analyses evidenced the relationship between the models' parameters and the relative differences between the models' predictions. The relative difference can be used to estimate the consistency between the models. Furthermore, the study showed that the tiered approach is not generally applicable to all exposure situations. These findings emphasize the need for a multiple-model approach to assessing critical exposure scenarios under REACH. Moreover, in combination with occupational exposure measurements, they might also be used for future studies to improve prediction accuracy
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