Mesure non paramétrique des efficacités : une approche duale

L'efficience des politiques de régulation des marchés, notamment agricoles, se révèle largement dépendante des niveaux d'efficacité micro-économique des agents concernés. Après un résumé de la littérature sur les mesures de l'efficacité, celles-ci sont présentées dans une double approche primale et duale. Le système de prix observé est utilisé sous l'angle dual, ce qui permet un encadrement des technologies et des mesures de l'efficacité tant technique qu'allocative

Surgically created double-orifice left atrioventricular valve: A valve-sparing repair in selected atrioventricular septal defects

AbstractObjectives: Some features of the left atrioventricular valve (large mural leaflet, dystrophic tissue) represent a challenge for repair of atrioventricular septal defects without postoperative regurgitation. A retrospective study was conducted to evaluate the results of surgically creating a double-orifice left atrioventricular valve in such circumstances. Clinical results were analyzed according to valvular and subvalvular left atrioventricular valve measurements in pathologic specimens with atrioventricular septal defects. Methods: Among 157 patients operated on for atrioventricular septal defect since October 1989, 10 patients underwent primary repair (n = 8) or reoperation (n = 2) by this procedure. Median age at repair was 3.3 years (0.1-33 years). Anatomic types were complete (n = 3), intermediate (n = 5), and partial (n = 2). Preoperative moderate to severe left atrioventricular valve regurgitation was present in 6 patients. After the repair (two-patch technique in complete atrioventricular septal defect, cleft closed in each case), these 10 patients were found to have moderate to severe residual regurgitation not amenable to repair by annuloplasty. The top edge of the mural leaflet was anchored to the facing free edge of the cleft. Results: No hospital death or morbidity was observed. Left atrioventricular valve regurgitation was absent or trivial (8 patients) and mild (2 patients). Color-coded echocardiography did not show significant left atrioventricular valve stenosis. The mean diastolic pressure gradient across the left atrioventricular valve was 3.2 ± 1.1 mm Hg (1.4-4.5 mm Hg). At a median follow-up of 72 months (6-91 months), there was 1 late death, unrelated to left atrioventricular valve malfunction, due to pulmonary vascular obstructive disease. Left atrioventricular valve regurgitation did not increase over time, except in 1 patient in whom regurgitation recently progressed from mild to moderate. At rest, the mean diastolic pressure gradient across the left atrioventricular valve was 3.8 ± 2.9 mm Hg (1.5-11.2 mm Hg). One child had an early moderate stenosis without pulmonary hypertension. Studies on pathologic specimens (n = 34) indicated that long chordal lengths and large mural leaflet size are essential independent anatomic features to assess its feasibility. Conclusions: Surgical creation of a double-orifice left atrioventricular valve is an effective additional procedure for repair of atypical cases of atrioventricular septal defect. The operation may decrease the need for reoperation or left atrioventricular valve replacement. (J Thorac Cardiovasc Surg 2001;121:352-65

Réforme de la Politique Agricole Commune : évolution des rendements céréaliers entre inefficacité technique et prix-efficacité

Cette étude tente de justifier, au sein du secteur agricole, l'hypothèse suivant laquelle le niveau d'efficacité micro-économique conditionne largement le degré d'efficience des politiques de régulation des marchés. L'illustration porte sur la toute récente réforme de la Politique Agricole Commune qui s'est donnée comme catalyseur une baisse notable du prix des céréales. Un cadre méthodologique non paramétrique permet de révéler les inefficacités proprement techniques de même que les inefficacités allocatives, c'est-à-dire relatives au système de prix. Cette approche est appliquée à l'examen d'échantillons d'exploitations céréalières du RICA, pour les années 1987 à 1990. Les inefficacités techniques observées s'interprètent comme des gains potentiels de productivité traduits ici sous forme d'accroissement des rendements céréaliers à l'hectare. Pour l'année 1990, l'inefficacité technique serait en moyenne d'environ 10% sur l'échantillon considéré. La résorption de cette seule inefficacité technique pourrait conduire à une augmentation de 11,2% des rendements céréaliers. L'effet escompté du gel de 15% des terres sur l'offre céréalière sera donc vraisemblablement amorti. Ce résultat global se différencie suivant les régions et la taille des exploitations

Left-sided lesions after anatomic repair of transposition of the great arteries, ventricular septal defect, and coarctation: Surgical factors

AbstractObjectiveThis study was undertaken to identify potential anatomic and surgical factors creating left-sided lesions, namely recoarctation of the aorta and neoaortic regurgitation, after anatomic repair of transposition of the great arteries with ventricular septal defect and aortic coarctation.MethodsFrom 1983 to September 2002, 109 survivors out of 120 patients were studied. Two-stage repair was performed in 42 patients (group A), and single-stage repair was performed in 67 (groups B and C). Before repair, the diameters of the ascending aorta and main pulmonary artery were measured. In the patients with single-stage repair, coarctation was repaired by extended end-to-end anastomosis in 35 patients (group B) and by pulmonary homograft patch augmentation in 32 patients (group C). The ventricular septal defect was closed through the pulmonary artery in 70 patients and through the right ventricle or atrium in 39 patients. The neoaorto-aortic discrepancy was treated by V-shaped resection of the posterior sinus of Valsalva in 7 cases, pulmonary homograft patch in 32 cases, and anterior splitting of the ascending aorta in all cases. Before discharge from the hospital, neoaortic root and ascending aorta diameters and aortic regurgitation grade were recorded. Neoaortic regurgitation progression and reintervention were the end points of follow-up (97.2 ± 61.2 months).ResultsEarly and late survivals were significantly better in group C (P < .001). Risk factors for neoaortic regurgitation at discharge by univariate analysis were single-stage repair (P < .05) and ventricular septal defect closure through the pulmonary artery (P = .0076). On multivariate analysis, the latter was the only risk factor for neoaortic regurgitation at discharge and at last follow-up. Multivariate analysis showed that higher neoaortic root/ascending aorta ratio and ventricular septal defect closure through the pulmonary artery were risk factors for neoaortic regurgitation evolution at last follow-up. There were 29 reinterventions, 19 for recoarctation of the aorta and 10 for neoaortic regurgitation with or without aortic root dilatation. Group B (P < .05), high neoaortic root/ascending aorta ratio (P < .01), and progressive neoaortic regurgitation (P < .05) were risk factors for recoarctation of the aorta. Group A was a risk factor for aortic valve replacement at 10 years (P < .05).ConclusionNeonatal single-stage repair with pulmonary homograft aortic augmentation remains the optimal approach to transposition of the great arteries with ventricular septal defect and aortic coarctation. It provides better early and late survivals and freedoms from left-sided lesions. Avoidance of late recoarctation of the aorta and progressive neoaortic regurgitation requires meticulous closure of the ventricular septal defect and evenly sized reconstruction of the aorta from root to distal arch

Severe Compromise of Preosteoblasts in a Surgical Mouse Model of Bisphosphonate-Associated Osteonecrosis of the Jaw.

Objectives: The effect of amino-bisphosphonates on osteoblastic lineage and its potential contribution to the pathogenesis of bisphosphonate-associated osteonecrosis of the jaw (BONJ) remain controversial. We assessed the effects of zoledronic acid (ZOL) on bone and vascular cells of the alveolar socket using a mouse model of BONJ. Material and Methods: Thirty-two mice were treated twice a week with either 100 μg/kg of ZOL or saline for 12 weeks. The first left maxillary molar was extracted at the third week. Alveolar sockets were assessed at both 3 weeks (intermediate) and 9 weeks (long-term) after molar extraction by semi-quantitative histomorphometry for empty lacunae, preosteoblasts (Osterix), osteoclasts (TRAP), and pericyte-like cells (CD146). Also, the bone microarchitecture was assessed by micro-CT. Results: Osteonecrotic-like lesions were observed in 21% of mice. Moreover, a decreased number of preosteoblasts contrasted with the increased number of osteoclasts at both time points. In addition, osteoclasts display multinucleation and detachment from the endosteal surface. Furthermore, the number of pericyte-like cells increased at the intermediate time point. The alveolar bone mass increased exclusively with long-term ZOL treatment. Conclusion: The severe imbalance between bone-forming cells and bone-resorbing cells showed in this study could contribute to the pathogenesis of BONJ

Impact of early complications on outcomes in patients with implantable cardioverter-defibrillator for primary prevention

International audienceBackground - The lifesaving benefit of implantable cardioverter-defibrillators (ICDs) has been demonstrated. Their use has increased considerably in the past decade, but related complications have become a major concern. Objective - The purpose of this study was to assess the incidence and effect on outcomes of early (≤30 days) complications after ICD implantation for primary prevention in a large French population. Methods - We analyzed data from 5539 patients from the multicenter French DAI-PP (Défibrillateur Automatique Implantable-Prévention Primaire) registry (2002-2012) who had coronary artery disease or dilated cardiomyopathy and were implanted with an ICD for primary prevention. Results - Overall, early complications occurred in 707 patients (13.5%), mainly related to lead dislodgment or hematoma (57%). Independent factors associated with occurrence of early complications were severe renal impairment (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.17-2.37, P = .02), age ≥75 years (OR 1.01, 95% CI 1.00-1.02, P = .03), cardiac resynchronization therapy (OR 1.58, 95% CI 1.16-2.17, P = .01), and anticoagulant therapy (OR 1.28, 95% CI 1.02-1.61, P = .03). During a mean ± SD follow-up of 3.1 ± 2.3 years, 824 (15.8%) patients experienced ≥1 late complication (>30 days), and 782 (14.9%) patients died. After adjustment, early complications remained associated with occurrence of late complications (OR 2.15, 95% CI 1.73-2.66, P < .0001) and mortality (OR 1.70, 95% CI 1.34-2.17, P = .003). Conclusion - Early complications are common after ICD implantation for primary prevention, occurring in 1 in 7 patients, and are associated with an increased risk of late complications and overall mortality. Further studies are needed to investigate the underlying mechanisms of such associations

Mesure non paramétrique des efficacités : une approche duale

L'efficience des politiques de régulation des marchés, notamment agricoles, se révèle largement dépendante des niveaux d'efficacité micro-économique des agents concernés. Après un résumé de la littérature sur les mesures de l'efficacité, celles-ci sont présentées dans une double approche primale et duale. Le système de prix observé est utilisé sous l'angle dual, ce qui permet un encadrement des technologies et des mesures de l'efficacité tant technique qu'allocative

[Modélisation de l'évolution des rendements céréaliers : de l'inefficacité technique à l'efficacité prix]

National audienceCet article tente de justifier l'hypothèse selon laquelle le niveau d'efficacité micro-économique conditionne largement le degré d'efficience des politiques de régulation de marché. Dans cette optique, nous proposons une analyse de l'évolution des rendements céréaliers suite à la réforme de la PAC en tenant compte de différents niveaux d'efficacité économique. Dans une première partie, nous supposons que les agriculteurs ne sont pas tous sur les frontières de production. A l'aide d'une approche non paramétrique, nous mesurons leur efficacité technique que ce soit à facteur terre variable ou quasi-fixe. Une croissance des rendements céréaliers semble alors possible si tous les producteurs résorbent leur inefficacité technique. Dans une seconde partie, nous supposons que tous les producteurs sont "profit maximizers". A l'aide d'une approche paramétrique, nous constatons une baisse des rendements céréaliers atténuée par quelques effets amortisseurs

Pricing organic nitrogen under the weak disposability assumption : an application to the French pig sector

L'approche non paramétrique Data Envelopment Analysis (DEA) est utilisée pour mesurer l'efficacité technique. Différents modèles sont évalués à partir des données du Réseau d'information comptable agricole (RICA 1991) sur les exploitations porcines. L'azote organique, coproduit de l'activité d'élevage, peut être utilisé pour la fertilisation des cultures mais au-delà d'un certain niveau d'épandage, son utilisation peut concourir à la pollution des eaux de surface et des nappes phréatiques. Dans cet article, l'hypothèse de libre disposition de l'azote organique est affaiblie pour tenir compte du coût lié à l'élimination des pollutions. Les mesures de l'efficacité déterminées sous hypothèse de forte et de faible disponibilité de l'azote organique sont comparées, et l'utilisation de l'information duale fournie par l'approche DEA permet de donner un prix implicite de l'azote organique ; ce prix pouvant ensuite être comparé au coût unitaire des différentes techniques de traitement des déjections animales

Hepatic apo B gene expression during fetal bovine development

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