Monetary value of a life expectancy gain due to reduce air pollution : lessons

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Evaluation monétaire d’un gain d’espérance de vie dû à une réduction de la pollution de l’air : les enseignements d’une évaluation contingente en France

International audienceThis paper presents the results of a contingent valuation in France of the life expectancy gain due to a reduction of air pollution. A questionnaire developed by Krupnick at al. [2002] for North America was translated and administered to 300 individuals aged 40 to 75, but by contrast to the application in other countries, an open question was added after each set of bids and at the end of the questionnaire the willingness-to-pay (WTP) values were recalled to give the respondents the opportunity to correct their values. Each questionnaire was followed by detailed written debriefing to learn how the respondents interpreted the questions. Furthermore, to test the robustness of the answers and provide guidance for improving the questionnaire, five variants were tested (with about 50 individuals for each), including variants phrased in terms of life expectancy gain. That allows to evaluate the sensitivity of the answers to the bids offered, and to the way how the good is described. The results are used to provide estimates for the value of a life year (VOLY): they range from 0.020 to 0.220 M?. The wide scatter of the results is a reflection of the difficulties that the respondents have in understanding risk reductions and replying to the WTP question.Ce papier présente les résultats d’une enquête d’évaluation contingente effectuée en France afin d’estimer les gains en termes d’espérance de vie de la réduction de la pollution de l’air. Le questionnaire utilisé a été développé par Krupnick at al. [2002] pour les Etats Unis. Il a été traduit et administré à 300 individus âgés de 40 à 75 ans. Le questionnaire original a été modifié. D’une part, une question ouverte a été ajoutée après chacune des trois séries d’offre. D’autre part, à la fin du questionnaire et après avoir rappelé au répondant les valeurs de consentement à payer exprimées, l’opportunité lui était donnée de modifier ces valeurs. Chaque questionnaire se termine par un ″debriefing″ écrit détaillé afin d’appréhender comment les personnes interrogées avaient interprété les questions posées. De plus, afin de tester la robustesse des réponses, cinq variantes du questionnaire initial ont été testées sur des échantillons composés d’environ 50 individus chacun. Ces variantes incluaient en particulier des scénarios où le bénéfice issus de la réduction de la pollution de l’air était exprimé en terme de gain d’espérance de vie. Il a alors été possible de tester la sensibilité des réponses recueillies aux offres proposées ou à la description retenue afin de présenter le ″bien″ à évaluer. Pour chaque scénario une ″valeur d’une année de vie″ (VOLY) a été estimée. Ces valeurs sont comprises entre 0.020 to 0.220 M€. Cette forte dispersion reflète la grande difficulté qu’ont les personnes interrogées à comprendre les concepts de variation de risque et à répondre à ces propositions en terme de consentement à payer

Monetary Value of a Life Expectancy Gain due to Reduced Air Pollution : Lessons from a Contingent Valuation in France

This paper presents the results of a contingent valuation in France of the life expectancy gain due to a reduction of air pollution. A questionnaire developed by Krupnick at al. [2002] for North America was translated and administered to 300 individuals aged 40 to 75, but by contrast to the application in other countries, an open question was added after each set of bids and at the end of the questionnaire the willingness-to-pay (WTP) values were recalled to give the respondents the opportunity to correct their values. Each questionnaire was followed by detailed written debriefing to learn how the respondents interpreted the questions. Furthermore, to test the robustness of the answers and provide guidance for improving the questionnaire, five variants were tested (with about 50 individuals for each), including variants phrased in terms of life expectancy gain. That allows to evaluate the sensitivity of the answers to the bids offered, and to the way how the good is described. The results are used to provide estimates for the value of a life year (VOLY): they range from 0.020 to 0.220 M?. The wide scatter of the results is a reflection of the difficulties that the respondents have in understanding risk reductions and replying to the WTP question.mortality risk, value of life year, value of statistical life, value of prevented fatality, medical treatment, elicitation question willingness-to-pay

Evaluation of Gonadal Function in 107 Intersex Patients by Means of Serum Antimüllerian Hormone Measurement.

International audienceFetal male sexual differentiation is driven by two testicular hormones: testosterone (synthesized by interstitial Leydig cells) and antimüllerian hormone (AMH; produced by Sertoli cells present in the seminiferous tubules). Intersex states result either from gonadal dysgenesis, in which both Leydig and Sertoli cell populations are affected, or from impaired secretion or action of either testosterone or AMH. Until now, only Leydig cell function has been assessed in children with ambiguous genitalia, by means of testosterone assay. To determine whether serum AMH would help in the diagnosis of intersex conditions, we assayed serum AMH levels in 107 patients with ambiguous genitalia of various etiologies. In XY patients, AMH was low when the intersex condition was caused by abnormal testicular determination (including pure and partial gonadal dysgenesis) but was normal or elevated in patients with impaired testosterone secretion, whereas serum testosterone was low in both groups. AMH was also elevated during the first year of life and at puberty in intersex states caused by androgen insensitivity. In 46,XX patients with a normal male phenotype or ambiguous genitalia, in whom the diagnosis of female pseudohermaphroditism had been excluded, serum AMH levels higher than 75 pmol/L were indicative of the presence of testicular tissue and correlated with the mass of functional testicular parenchyma. In conclusion, serum AMH determination is a powerful tool to assess Sertoli cell function in children with intersex states, and it helps to distinguish between defects of male sexual differentiation caused by abnormal testicular determination and those resulting from isolated impairment of testosterone secretion or action

Principles of chromatin organization in yeast: relevance of polymer models to describe nuclear organization and dynamics

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Somatic mosaicism has been implicated as a causative mechanism in a number of genetic and genomic disorders. X-linked acrogigantism (XLAG)syndrome is a recently characterized genomic form of pediatric gigantism due to aggressive pituitary tumors that is caused by submicroscopic chromosome Xq26.3 duplications that include GPR101. We studied XLAG syndrome patients (n = 18)to determine if somatic mosaicism contributed to the genomic pathophysiology. Eighteen subjects with XLAG syndrome caused by Xq26.3 duplications were identified using high-definition array comparative genomic hybridization (HD-aCGH). We noted that males with XLAG had a decreased log2 ratio (LR)compared with expected values, suggesting potential mosaicism, whereas females showed no such decrease. Compared with familial male XLAG cases, sporadic males had more marked evidence for mosaicism, with levels of Xq26.3 duplication between 16.1 and 53.8% These characteristics were repl