Extension d’un modèle de fissuration multi échelle en mode mixte (I+II) et mise en oeuvre dans un code XFEM.

Un modèle de fissuration en mode mixte I+II, permettant de prendre en compte à l'échelle macroscopique le comportement élasto-plastique des aciers en pointe de fissure, a été intégré dans un code éléments-finis étendu (X-FEM) développé au LMT. Le code ainsi enrichi est ensuite utilisé pour prédire la réponse de structures fissurées à des chargements cycliques en mode mixte en tenant compte des effets mémoire liés au comportement élasto-plastique du matériau

Aménagements des parcours de poulets Label Rouge et Biologiques

La présence d'un parcours est un élément majeur caractérisant les productions de volailles sous signes de qualité Label Rouge et Biologique. Pour permettre la durabilité de ces modes de production, il est nécessaire d'optimiser la gestion des parcours, afin de concilier au mieux les besoins des volailles, la production d'un revenu supplémentaire pour l'éleveur et une gestion environnementale pertinente. Pour cela, il était avant tout nécessaire de connaître la diversité des caractéristiques des parcours existants. Une enquête a été réalisée auprès des éleveurs de différents bassins de production français, et a permis de décrire les aménagements arborés des parcours, et les pratiques de gestion. Sept types d'aménagements des parcours ont été mis en évidence selon la présence ou non de haies périphériques, d'arbustes à proximité des trappes des bâtiments à vocation d'aménagements zootechniques, d'arbres à distance plus ou moins éloignée du bâtiment, de plantations arborées entre ces deux zones de parcours. Cette typologie permet d'apporter des préconisations d'amélioration adaptées à chaque situation

Maîtriser la reproduction des petits ruminants

En élevage biologique, les traitements hormonaux pour gérer la reproduction des animaux (induction et synchronisation des chaleurs) sont interdits, alors qu'ils sont fréquemment utilisés en élevages ovins et caprins conventionnels. Leur utilisation dans ces derniers pourrait toutefois être remise en cause par une nouvelle réglementation. Afin de proposer des alternatives en termes de gestion de la reproduction en élevages ovins et caprins, le programme Casdar Reprobio s'est penché sur deux innovations : - l'utilisation de phéromones de synthèse pour induire les chaleurs ; - des appareils de détection automatisés des chaleurs. Grâce à une enquête, ces deux outils ont été soumis, pour avis, à des éleveurs et des professionnels de l'élevage, en agricultures biologique et conventionnelle. Leurs retours sont présentés dans cet article. L'utilisation des phéromones, qui doit toutefois faire face à un vide juridique en bio, suscite l'intérêt, alors que les détecteurs automatisés de chaleurs posent davantage de questions

Brachytherapy for lower lip epidermoid cancer: tumoral and treatment factors influencing recurrences and complications

From 1972 to 1991, 237 patients with squamous cell carcinoma of the lower lip were treated by exclusive LDR brachytherapy (192Ir). There were 158 T1, 61 T2, 17 T3 and 1 T4 with 231 N0, 3 N1 and 3 N2 patients. The actuarial values at 5 years for local and regional controls, overall and specific survivals were 95%, 91%, 74% and 91%. Salvage treatment increased local control up to 99% and regional control to 94%. No heterolabial recurrence has been observed since the entire lip is treated, even for small tumors. The regional control depends closely on the thickness of the labial tumor (≥ 1 cm, p 1.4 cm, p = 0.018) and particularly to the thickness of normal tissue included in the 85% isodose (treated thickness - tumoral thickness > 0.4 cm, p = 0.025). The use of a leaded protection and low linear radioactivity wires (<2 mCi/cm, <8.6 μGy/h · m2/cm) especially for large target volumes is required to lessen late complications. Based on this review, we advocate exclusive brachytherapy for small and intermediate tumors, with elective bilateral submaxillary and submental dissection for thick, high grade or commissure tumors. Simple recommendations are made to assure quality of the brachytherapy treatment. © 1994.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Relation between hysterectomy, oophorectomy and the risk of incident differentiated thyroid cancer: The E3N cohort

International audienceBACKGROUND:Thyroid cancers are threefold more frequent in women than in men. A role of reproductive or hormonal factors has been suggested but with contradictory results. We investigated potential associations between history of hysterectomy, with or without oophorectomy, and history of benign gynaecological disease (uterine fibroids, endometriosis) and the incidence of differentiated thyroid cancer, in a large French prospective cohort.METHODS:A total of 89 340 women from the E3N cohort were followed up between 1990 and 2012. Gynaecological diseases treated by surgery were self-reported. Thyroid cancers were validated by histological reports. Time-dependent covariates included smoking status, BMI and history of benign thyroid disease. Cox proportional hazard models with age as timescale were used to estimate Hazard Ratios (HR) and 95% confidence intervals (CI).RESULTS:A total of 412 cases of thyroid cancer were diagnosed during follow-up. A history of hysterectomy was associated with an increased risk of differentiated thyroid cancer (adjusted HR=2.05; 95%CI: 1.65-2.55). The association was not altered after further adjustment for reproductive factors. Endometriosis, uterine polyps, ovarian cysts and oophorectomy without hysterectomy were not associated with the risk of thyroid cancer. A history of fibroids was also significantly related to the risk of thyroid cancer over the follow-up period (adjusted HR=1.91; 95%CI: 1.50-2.44) and the increased risk persisted after adjustment for history of hysterectomy.CONCLUSIONS:Women who had either a history of fibroids or hysterectomy had an increased risk of differentiated thyroid cancer. These findings suggest shared biological mechanisms between fibroids and thyroid cancer, which deserve to be further dissected

Associations between serum lipids and breast cancer incidence and survival in the E3N prospective cohort study.

International audiencePURPOSE:Several mechanistic studies support a role of cholesterol or its metabolites in breast cancer etiology, but associations have been inconsistent in epidemiological studies. In observational studies, possible reverse causation must be accounted for using a prospective design. We investigated prospective associations between pre-diagnostic serum lipid concentrations [total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides], and both breast cancer risk and survival in the E3N cohort study.METHODS:Analyses were performed on 583 cases from the E3N prospective cohort diagnosed between 1994 and 2005, and 1,043 controls matched on date, age, recruitment center and menopausal status at blood collection. Odds ratios (OR) and 95% confidence intervals were estimated using conditional logistic regression. Risks of recurrence were estimated among cases using Cox proportional hazards model. Models were adjusted for lifestyle risk factors and mutually adjusted for lipid concentrations. Survival analyses were additionally adjusted for tumor characteristics.RESULTS:Overall, there was no association between any serum lipid and breast cancer risk or survival. In stratified analyses, statistically significant interaction was observed between TC and menopausal status (P interaction = 0.05) and between TC and waist circumference (P interaction = 0.03), although the ORs did not reach statistical significance in any of the strata. There was no statistically significant effect modification by BMI, time between blood donation and diagnosis or ER status.CONCLUSIONS:Our results suggest that serum lipids are not associated with breast cancer risk overall, but that menopausal status and waist circumference should be considered in further studies

A comparison between different prediction models for invasive breast cancer occurrence in the French E3N cohort

Breast cancer remains a global health concern with a lack of high discriminating prediction models. The k-nearest-neighbor algorithm (kNN) estimates individual risks using an intuitive tool. This study compares the performances of this approach with the Cox and the Gail models for the 5-year breast cancer risk prediction. The study included 64,995 women from the French E3N prospective cohort. The sample was divided into a learning (N = 51,821) series to learn the models using fivefold cross-validation and a validation (N = 13,174) series to evaluate them. The area under the receiver operating characteristic curve (AUC) and the expected over observed number of cases (E/O) ratio were estimated. In the two series, 393 and 78 premenopausal and 537 and 98 postmenopausal breast cancers were diagnosed. The discrimination values of the best combinations of predictors obtained from cross-validation ranged from 0.59 to 0.60. In the validation series, the AUC values in premenopausal and postmenopausal women were 0.583 [0.520; 0.646] and 0.621 [0.563; 0.679] using the kNN and 0.565 [0.500; 0.631] and 0.617 [0.561; 0.673] using the Cox model. The E/O ratios were 1.26 and 1.28 in premenopausal women and 1.44 and 1.40 in postmenopausal women. The applied Gail model provided AUC values of 0.614 [0.554; 0.675] and 0.549 [0.495; 0.604] and E/O ratios of 0.78 and 1.12. This study shows that the prediction performances differed according to menopausal status when using parametric statistical tools. The k-nearest-neighbor approach performed well, and discrimination was improved in postmenopausal women compared with the Gail model

Maîtriser la reproduction des petits ruminants

National audienceEn agriculture conventionnelle (AC), pour gérer la reproduction des ovins et caprins, des traitements hormonaux sont utilisés. Ils permettent de préparer l'insémination animale (IA) ou de grouper les mises-bas par l'induction et la synchronisation des chaleurs. En AB, ces traitement hormonaux sont interdits, et leur utilisation pourrait se voir limitée en conventionnel par des évolutions réglementaires. Ainsi, le programme Casdar Reprobio amis à l'étude deux nouveaux outils : les phéromones de synthèse (alternative à la synchronisation hormonale de chaleurs) et la détection automatisée des chaleurs (pour faciliter la mise en place de l'IA sur chaleurs synchronisées ou pas). Voici les retours d'éleveurs et d’intervenants en élevages sur ces innovations

Le répertoire de l’Opéra de Paris (1671-2009)

L'Opéra de Paris, loin de l'uniformité qui règne aujourd'hui entre tous les opéras du monde, a longtemps fait cavalier seul : en jouant majoritairement des œuvres anciennes, en se refusant aux langues étrangères, en cultivant jalousement sa propre tradition. Les études réunies ici explorent les principales options qui structurent son répertoire pendant plus de trois siècles : l'ancien et le nouveau, l'équilibre entre opéra et ballet, l'inclusion progressive d'autres genres et d'autres styles, la montée en puissance de la mise en scène. Ce répertoire forme un continent en grande partie englouti, mais il suffit d'en chercher la problématique sous-jacente pour qu'il nous apparaisse sous un jour étrangement familier